WO2025230428A1 - Sustained release bolus dosage form - Google Patents

Abstract

The disclosure provides a bolus configured for administration to an animal, wherein said bolus is configured to release a substance to the animal with extended release. The bolus including (i) a core including at least one active ingredient and at least one carrier; (ii) a casing that covers at least a portion of the core; wherein the core includes (i) at least one active ingredient; (ii) at least a first cellulosic polymer that is at least about 10% w/w of the core; and (iii) optionally one or more additional excipient, preferably a carrier.

Description

Sustained release bolus dosage form

This application claims priority to New Zealand provisional applications NZ 810651 and NZ 813436 (filed on 1 May 2024 and 1 August 2024, respectively), the entire contents of which are incorporated by reference.

Field of the disclosure

The present disclosure relates to improvements in devices and methods for delivery of substances to animals, and in particular to devices and methods for administering at least one substance to the rumen of a ruminant animal, and methods of manufacturing of the devices.

Background of the disclosure

In farming it is often necessary to deliver substances to animals. This can be for various purposes, including but not limited to treatment or prevention of disease and to increase animal production.

There are various devices (eg dosage forms) and methods to deliver substances such as medicaments to animals. Some substances are for administration to the rumen of ruminant animals. Some dosage forms are for extended release (ie sustained release) to the rumen of ruminant animals. Extended release dosage forms present challenges relating to extended control of the quantity of the dosage released, and reliability of such control over time and across batches.

Extended release within the rumen presents further challenges owing to the local environment, which is less well studied, particularly with respect to extended release dosage forms, than the digestive tract of single-stomached organisms (such as humans). Controlled extended release of the substance in the rumen can increase the efficacy and reduce the side effects of administered dosage forms by reducing the maximum concentration of the active substance to a concentration that is more consistent with the effective concentration of the active substance, and maintaining such an effective concentration over an extended period.

There is a need for improved dosage forms for extended release to the rumen. Preferably, these dosage forms provide controlled extended release to the rumen, more preferably, the control is maintained until the majority of the substance is released from the dosage form to the rumen.

A sustained release may be particularly desired wherein a low dosage of active substance for an extended period may provide best efficacy of treatment.

The challenges associated with extended release of a substance increase with the amount of extension desired. Extending release for hours, days, weeks and months is progressively more difficult, as is controlling release to deliver a biologically effective and non-toxic dosage across the extended timeframe. There is a need for improved dosage forms for delivering substances with an extended release profile to the rumen of a ruminant animal for increased periods of time. Preferably, the extended release is suitably controlled over that time period.

Reference to any prior art in the specification is not an acknowledgment or suggestion that this prior art forms part of the common general knowledge in any jurisdiction or that this prior art could reasonably be expected to be understood, regarded as relevant, and/or combined with other pieces of prior art by a skilled person in the art.

Summary of the disclosure

In one aspect, the present disclosure provides a bolus including: a core; a casing that covers at least a portion of the core; wherein the core includes (i) at least one active ingredient; (ii) at least a first cellulosic polymer that is at least about 10% w/w of the core; and (iii) optionally one or more additional excipient. Preferably, the first cellulosic polymer is a hydrophobic cellulosic polymer. Preferably, the first cellulosic polymer is an extended release polymer. Preferably, the first cellulosic polymer is a hydrophobic extended release polymer.

Preferably the additional excipient is a carrier. In some embodiments, the additional excipient is an integrity agent. Optionally, the integrity agent is selected from the group consisting of hydroxypropyl methylcellulose, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), carrageenan, guar gum, xanthan gum, sodium alginate, locust bean gum, polyvinylpyrrolidone (PVP), polyvinylpyrrolidone-vinyl acetate copolymer (PVP/VA), a polyacrylic acid and/or their co-polymer variants, combinations thereof, combinations with talc thereof, and co-polymers thereof. Optionally, the integrity agent is at least about 10% w/w of the core. Optionally, the integrity agent is a second cellulosic polymer. Preferably, the integrity agent is less hydrophobic and/or less hygroscopic than the first cellulosic polymer.

In another aspect, the present disclosure provides a bolus including: a core; a casing that covers at least a portion of the core; wherein the core includes (i) at least one active ingredient; (ii) one or more of a hydrophobic cellulosic polymer, polyisobutylene, ethyl vinyl acetate (EVA), a functional wax with a melting point less than about 120 °C; and (iii) optionally one or more additional excipient; wherein the one or more of a hydrophobic cellulosic polymer, polyisobutylene, ethyl vinyl acetate (EVA), a functional wax with a melting point less than about 120 °C, are at least about 10% w/w of the core.

In another aspect, the present disclosure provides a bolus including: a core a casing that covers at least a portion of the core; wherein the core includes (i) at least one active ingredient; (ii) at least a first cellulosic polymer and at least a second cellulosic polymer; and (iii) optionally one or more additional excipient. Preferably, the first cellulosic polymer is a hydrophobic cellulosic polymer. Preferably, the first cellulosic polymer is an extended release polymer. Preferably, the first cellulosic polymer is a hydrophobic extended release polymer.

Preferably the excipient is a carrier. Preferably, the second cellulosic polymer is a hydrophilic polymer. Preferably, the second cellulosic polymer is an extended release polymer. Preferably, the second cellulosic polymer is a hydrophilic extended release polymer. Preferably, the first cellulosic polymer is at least about 10% w/w of the core. Preferably, the second cellulosic polymer is at least about 10% w/w of the core.

In any embodiment of a bolus of the disclosure, the bolus may be formulated to remain in the rumen following administration. Preferably the bolus is formulated to remains in the rumen for at least 8 weeks or at least 10 weeks.

In any embodiment of a bolus of the disclosure, optionally the core does not include an additional excipient.

In any embodiment of a bolus of the disclosure, the bolus is formulated for diffusion extended release.

In any embodiment of a bolus of the disclosure, the second cellulosic polymer and/or integrity agent may be selected from the group consisting of hydroxypropyl methylcellulose, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), carrageenan, guar gum, xanthan gum, sodium alginate, locust bean gum, combinations thereof, combinations with talc thereof, and co-polymers thereof. Preferably, the second cellulosic polymer and/or integrity agent is hydroxypropyl methylcellulose. Optionally, the second cellulosic polymer and/or integrity agent is about 10 to about 25% or about 14 to about 20% w/w of the core.

In any embodiment of a bolus of the disclosure, the first (or at least one) cellulosic polymer may be selected from the group consisting of ethyl cellulose, polyisobutylene, ethyl vinyl acetate (EVA), all functional waxes with a melting point less than about 120 °C, combinations thereof, combinations with talc thereof, and co-polymers thereof. Preferably, the first cellulosic polymer is ethyl cellulose. Optionally, the at least one (or first) cellulosic polymer is about 10 to about 40%, about 15 to about 35%, or about 20 to about 30% w/w of the core.

In any embodiment of a bolus of the disclosure, the core optionally further comprises a channelling agent. Optionally, the core does not comprise hydrophobic fumed silica. Optionally, the core does not comprise a wax. Optionally, the core is about 20 to about 55% w/w of the bolus, preferably about 30 to about 45%, or about 37% w/w of the bolus. In any embodiment of a bolus of the disclosure, the casing optionally includes one or more biodegradable polymers. In alternate embodiments, the casing includes one or more hydrophobic polymers. In some embodiments, the casing includes one or more non- biodegradable polymers, including polyvinyl chloride (PVC), polyethylene terephthalate (PET), Buna-S, nylon, polyvinyl butyral, polyethylene (low [LDPE], medium [MDPE], high [HDPE] or ultra high molecular weight [UHMWPE]), polypropylene (PP) and combinations thereof. In some embodiments, the casing includes one or more non-biodegradable polymers, including high-density polyethylene (HDPE), polypropylene (PP) and combinations thereof. Optionally, the casing includes one or more polymers selected from the list consisting of one or more polymers selected from the list consisting of polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co- adipate (PBSA), polylactic acid (PLA), poly-D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D- lactide) (TALC PDLA), Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof. Optionally, the casing includes one or more polymers selected from the list consisting of polyvinyl chloride (PVC), polyethylene terephthalate (PET), Buna-S, nylon, polyvinyl butyral, polyethylene (low [LDPE], medium [MDPE], high [HDPE] or ultra high molecular weight [UHMWPE]), polypropylene (PP), polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co-adipate (PBSA), polylactic acid (PLA), poly-D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D-lactide) (TALC PDLA), Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof. Optionally, the casing includes one or more polymers selected from the list consisting of high-density polyethylene (HDPE), polypropylene (PP), polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co-adipate (PBSA), polylactic acid (PLA), poly-D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene- acrylic copolymer (such as Joncryl®), talc-filled poly(D-lactide) (TALC PDLA), Poly(3- hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof. In some embodiments, the casing consists of one or more polymers selected from the list consisting of polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co-adipate (PBSA), polylactic acid (PLA), poly- D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D-lactide) (TALC PDLA), Poly(3- hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof, combinations thereof, and co-polymers thereof. Optionally, the casing is about 0.5 to about 2.0 mm thick, preferably about 1 .0 to about 1 .8 mm thick or about 1 .2 mm thick. Optionally, the casing is about 5% to about 15% w/w of the bolus, preferably about 7% to about 12%, or about 8% w/w of the bolus. Optionally, the casing includes one or more polymers selected from the list consisting of polylactic acid, polybutylene adipate terephthalate, combinations thereof, and co-polymers thereof. Optionally, the casing covers all of the core. Optionally, the casing is not configured to form one or more openings in at least part of the casing when exposing the casing to a temperature of between 35°C and 45°C, allowing the methane inhibiting agent to exit the bolus through said opening or openings; and/or wherein the casing is permeable and/or can become permeable to an active ingredient before exposing the casing to a temperature of between 35°C and 45°C.

In any embodiment of a bolus of the disclosure, the bolus comprises a therapeutically effective amount of an active ingredient. Optionally, the active ingredient is optionally a haloform. In some embodiments, the haloform is selected from the list of chloroform, bromoform, iodoform, or combinations thereof.

In any embodiment of a bolus of the disclosure, the bolus further comprises a densifier. Optionally, the densifier is either dispersed in the core, in or on the casing, or separate to the core and casing (preferably within the casing). Optionally, at least a portion of the densifier is present in a densifier matrix. Optionally, the densifier is about 30 to about 75% w/w of the bolus, preferably about 45 to about 65%, or about 55% w/w of the bolus.

In any embodiment of a bolus of the disclosure, the bolus is formulated to administer haloform to the rumen of the ruminant animal for at least 8 weeks after administration. Optionally, the bolus is formulated to administer haloform to the rumen of the ruminant animal for at least 20 weeks after administration.

In any embodiment of a bolus of the disclosure, the bolus optionally includes

• about 5% to about 15% (w/w) casing; • about 20 to about 55 (w/w) core; and

• about 30 to about 75 (w/w) densifier

In another aspect, the present disclosure provides a method of administering a methane inhibitor to a ruminant animal, the method including administering to the rumen of the ruminant animal the bolus in accordance with this disclosure.

In another aspect, the present disclosure provides a method of reducing methane production in the rumen of a ruminant animal, the method including administering to the rumen of the ruminant animal a bolus according to the present disclosure.

In embodiments of the methods of administration of the disclosure, the bolus administers haloform to the rumen of the ruminant animal for at least about 8 weeks after administration. Optionally, the bolus administers haloform to the rumen of the ruminant animal for at least about 20 weeks after administration.

In embodiments of the methods of administration of the disclosure, following administration of the bolus the bolus sinks below the liquid surface or to the bottom of the rumen.

In embodiments of the methods of administration of the disclosure, the bolus remains in the rumen following administration for at least about 8 weeks or at least about 20 weeks.

In embodiments of the methods of administration of the disclosure, following release of the active ingredient the bolus degrades in the rumen. Optionally, the degradation is until the remnants of the bolus is of a size that can safely pass through the ruminant.

In embodiments of the methods of administration of the disclosure, following administration of the bolus the methane emitted by the ruminant is reduced by about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80% by g/day. Optionally, this reduction occurs by about 5, about 10, or about 15 days following administration of the bolus. Optionally, the reduction continues for about 4 weeks, about 6 weeks, about 8 weeks, about 12 weeks, about 16 weeks or about 20 weeks. Optionally, the reduction continues at about 40 to about 90%, about 40 to about 70%, about 40 to about 50%, about 60 to about 90%, or about 70 to about 90% by g/day over the about 4 weeks, about 6 weeks, about 8 weeks, about 12 weeks, about 16 weeks or about 20 weeks.

In embodiments of the methods of administration of the disclosure, a second bolus is administered to the ruminant at about 8 to about 20 weeks, about 12 to about 20 weeks, about 8 to about 16 weeks or about 12 to about 16 weeks following the initial administration. Optionally, further bolus administration occurs regularly at these intervals. Optionally, this dosage regimen results in ongoing methane reduction of about 40 to about 90%, about 40 to about 70%, about 40 to about 50%, about 60 to about 90%, or about 70 to about 90% by g/day.

In embodiments of the methods of administration of the disclosure, the active ingredient is release from the bolus by diffusion.

In yet another aspect, the present disclosure provides a method of making a bolus, the method including: selecting a core and a casing inserting the core into the casing, optionally closing the casing to encapsulate or substantially encapsulates the core in the casing; wherein the core includes at least one active ingredient, preferably a haloform selected from the list of chloroform, bromoform, iodoform, or combinations thereof; and at least one carrier. Optionally, the bolus further includes a densifier either dispersed in the core, in or on the casing, or separate to the core and casing (preferably within the casing).

This method may be used to prepare bolus dosage forms according to the disclosure.

As used herein, except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising", "comprises" and "comprised", are not intended to exclude further additives, components, integers or steps. Further aspects of the present disclosure and further embodiments of the aspects described in the preceding paragraphs will become apparent from the following description, given by way of example and with reference to the accompanying drawings.

Brief description of the drawings

Figure 1a and Figure 1 b depict the bromoform release rate of Preparation 9A boluses, as described in Example 2.

Figure 2 depicts the bromoform release rate of Preparation 9B boluses, as described in Example 2.

Figure 3 depicts the bromoform release rate of a series of Preparations of varying bromoform, ethyl cellulose and hydroxypropyl methylcellulose concentration; as described in Example 3.

Figure 4 depicts the bromoform release rate of a series of Preparations of varying bromoform, ethyl cellulose and hydroxypropyl methylcellulose concentration; as described in Example 4.

Figure 5 depicts the bromoform release rate of a series of Preparations of varying bromoform, ethyl cellulose, hydroxypropyl methylcellulose and alginate concentration; as described in Example 5.

Figure 6 depicts the bromoform release rate of a series of Preparations of varying bromoform, ethyl cellulose, and hydrophobic fumed silica concentration; as described in Example 6.

Figure 7 depicts the bromoform release rate of a series of Preparations of varying carrier composition, comparing carriers comprising beeswax to those comprising ethyl cellulose; as described in Example 7. In Figure 7, the average release day once consistent (plateau) release rate is achieved was approximately as follows: Argenta HP- 58(Prototype 9A= -80 mg/day; Argenta HP-60 (Prototype 9B= -150 mg/day; CW-PW-50 (Prototype 4= -150 mg/day; Control= 0 mg/day; DNZ Treatment A(9A)= -80 mg/day; DNZ Treatment B(9B)= -150 mg/day; DNZ Treatment C(9Ax2)= -160 mg/day; DNZ Treatment D(9A+9B)= -230 mg/day; DNZ Treatment E(9Bx2)= -300 mg/day;Beeswax (Prototype 3)= -1000 mg/day; Argenta (Prototype 8A)= -170 mg/day). Figure 8 depicts a bolus of the disclosure (100), which includes a casing (101 ), a core (102), a closed region (103) and a densifier (104).

Figure 9 depicts the release profile of boluses loaded with matrix composed of 60% bromoform, 20% ethyl cellulose and 20% hydroxypropyl methylcellulose when placed in buffer at room temperature (RT: 25 °C), 30 °C, and 40 °C; as described in Example 9.

Figure 10 depicts the release profile of boluses loaded with matrix composed of 58.4% bromoform, 27.3% hydroxypropyl methylcellulose and 14.3% ethyl cellulose when placed in buffer at room temperature (RT: 25 °C), 30 °C, and 40 °C; as described in Example 9.

Figure 11 depicts the release profile of boluses with 0.9, 1.2, and 1.5 mm casing (90% polylactic acid (PLA) and 10% polybutylene adipate terephthalate (PBAT)) thicknesses loaded with matrix composed of 58.4 % bromoform, 27.3% hydroxypropyl methylcellulose and 14.3 % ethyl cellulose when placed in buffer at 40 °C; as described in Example 10.

Figure 12 depicts the release profile from boluses containing different EC:bromofrom ratio (4.5:1 vs 2.2:1 ) when the bromoform concentration in the core is 70% w/w, as described in Example 11.

Figure 13 depicts the release profile from boluses containing different EC: bromoform ratio (2.9:1 vs 2.7:1 ) when the bromoform concentration in the core is 60.3% w/w, as described in Example 11.

Figure 14 depicts the release profile from boluses containing the EC: bromoform ratio (3.1 :1 ) but different bromoform concentration (63% vs 58.4%) in the core, as described in Example 11.

Figure 15 depicts the release profile from boluses containing the same bromoform concentration (60 % w/w) in the matrix (dough) but different EC: bromoform ratio (3.3:1 vs 2.6:1 ) and loading, as described in Example 11. The bolus with F-5 formulation had 54.4 g of core and the bolus with F-12 formulation contained 60 g of core. Figure 16 depicts the release profile from boluses containing varying amounts of water as channelling agent, as described in Example 12.

Figure 17 depicts the release profile from boluses containing varying amounts of ethanol as channelling agent, as described in Example 13.

Figure 18 depicts the release profile from boluses containing varying amounts of DMSO as channelling agent, as described in Example 14.

Figure 19 depicts methane inhibition relative to control group over time in the animal study described in Example 15. Raw data presented as dashed lines, smoothed data from spline fit given as solid lines. Light grey band represents 50 - 70% inhibition relative to controls, dark grey band represents 70 - 100% inhibition.

Figure 20 depicts the area under the curve for mean methane emissions per group over time, excluding the pre-treatment period, in the animal study described in Example 15.

Figure 21 depicts the release profile of equivalent boluses containing EC (45) or EC-7, as described in Example 16.

Detailed description of the embodiments

In one aspect, the present disclosure provides a bolus including: a core; a casing that covers at least a portion of the core; wherein the core includes (i) at least one active ingredient; (ii) at least a first cellulosic polymer that is at least about 10% w/w of the core; and (iii) optionally one or more additional excipient.

In another aspect, the present disclosure provides a bolus including: a core; a casing that covers at least a portion of the core; wherein the core includes (i) at least one active ingredient; (ii) one or more of a hydrophobic cellulosic polymer, polyisobutylene, ethyl vinyl acetate (EVA), functional wax with a melting point less than about 120 °C; and (iii) optionally one or more additional excipient; wherein the one or more of a hydrophobic cellulosic polymer, polyisobutylene, ethyl vinyl acetate (EVA), functional wax with a melting point less than about 120 °C, are at least about 10% w/w of the core.

In another aspect, the present disclosure provides a bolus including: a core a casing that covers at least a portion of the core; wherein the core includes (i) at least one active ingredient; (ii) at least a first cellulosic polymer and at least a second cellulosic polymer; and (iii) optionally additional excipient.

There are specific substances that pose particular difficulty in the context of extended release delivery to the rumen. One class of compounds that are difficult to deliver to animals are hydrophobic compounds. A further class of compounds that are difficult to deliver to animals, particularly in a sustained release, are volatile or somewhatvolatile compounds. The properties of these compounds present challenges to developing technology for the sustained release of these hydrophobic and/or volatile/somewhat-volatile substances, particularly via an animal’s stomach. Haloforms such as bromoform are such substances. Surprisingly, the inventors have developed an extremely extended release (months) dosage form for delivering hydrophobic and/or volatile/somewhat-volatile substances to the rumen of ruminants, a relatively little studied environment relative to the gastrointestinal tract of single stomached animals. Surprisingly, the inventors have improved the release kinetics and duration of controlled release of the dosage form through development of the components of the core.

One specific purpose to administer substances to animals is to reduce the adverse effects of agriculture. For instance, various methane and nitrification inhibitors are known to be administered to animals to reduce or mitigate the adverse effects of the methane and nitrogen-containing compounds produced by the animals.

However, despite current efforts, climate change is creating a wide range of environmental and social impacts globally. It is widely understood that these impacts will only continue to increase over time. As a result, there has been a global push to reduce harmful greenhouse gas (GHG) emissions in an effort to avoid the worst effects of climate change.

The agricultural sector is considered to be a major source of GHG emissions. Total emissions of methane from global livestock accounts for an estimated 7.1 gigatons of CO2-equivalent per year, representing 14.5% of all anthropogenic GHG emissions. Therefore, this sector will play a key role in reducing overall GHG emissions.

The main GHGs released by agriculture are methane (CH4) and nitrous oxide (N2O), with the main source of methane emission attributed to livestock. Most methane is emitted when cattle, or other ruminant animals, burp. The amount of methane produced for each farm is directly related to the total animal feed intake, commonly measured as dry matter intake (DM I).

Countries which have a strong agricultural sector, such as New Zealand and other countries, face challenging goals in reducing agricultural emissions. For instance, the New Zealand government has introduced policies aimed to reduce methane emission by 24-50% before 2050. In New Zealand livestock methane production is estimated to comprise as much as half of the country's total GHG emissions. The reduction of methane is a critical component of meeting targets for emissions of GHGs and reducing the effects of global warming.

Release of GHGs by animals also has adverse effects on animal productivity. Any feed that is converted to a compound which is subsequently expired or released by the animal is an energy source that has not been converted to a productive use. Accordingly, for efficiency, it is important to optimise conversion of feeds into animal productivity, including in the form of weight gain or milk production.

Definitions Unless otherwise herein defined, the following terms will be understood to have the general meanings which follow.

A veterinary acceptable excipient is an excipient which upon administration to an animal subject is typically not deleterious to the subject. The skilled person will appreciate that in general veterinary acceptable excipients include pharmaceutically acceptable (ie acceptable for humans) excipients.

As used herein “haloform” is CHX3 where X is a halogen and each X atom may be a different halogen. Thus, “haloform” includes CHCIBr2 and the like. As used herein, “mixed haloform” refers to haloforms where not every X attached to the carbon atom is the same. In some embodiments, each X atom is the same.

As used herein, “degrade” and “degradation” do not require full break down of the bolus into other matter and full absorbance by the rumen fluid, but that instead only require that the bolus breaks sufficiently such that it may leave the rumen, for instance by passing through the digestive tract of the animal or being regurgitated.

As used herein, “feeds” refers to dry matter intake (DMI), supplements, grazing pasture, grains, or other feedstock.

As used herein, the term "effective amount" means that amount of an active ingredient or compound for delivery to the rumen that will elicit the biological or medical response of a tissue, system, or animal that is being sought, for instance, by a researcher or veterinarian. Furthermore, the term "therapeutically effective amount" means any amount which, as compared to a corresponding subject who has not received such amount, results in improved treatment, healing, prevention, or amelioration of a disease, disorder, or side effect, or a decrease in the rate of advancement of a disease or disorder. The term also includes within its scope amounts effective to enhance normal physiological function. For instance, a therapeutically effective amount of methane inhibiting agent such as a haloform reduces the methane output of an animal, preferably a ruminant.

It must be noted that as used herein and in the appended claims, the singular forms “a”, “an” and “the” include plural reference unless the context clearly dictates otherwise. Thus, for example, a reference to “a polymer” may include a plurality of polymers and a reference to “at least one carrier” may include one or more carriers, and so forth. The term “and/or” can mean “and” or “or”.

The term “(s)” following a noun contemplates the singular or plural form, or both.

Various features of the disclosure are described with reference to a certain value, or range of values. These values are intended to relate to the results of the various appropriate measurement techniques, and therefore should be interpreted as including a margin of error inherent in any particular measurement technique. Some of the values referred to herein are denoted by the term “about” to at least in part account for this variability. The term “about”, when used to describe a value, may mean an amount within ±25%, ±10%, ±5%, ±1% or ±0.1 % of that value.

As used herein, except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising", "comprises" and "comprised", are not intended to exclude further additives, components, integers or steps.

Modified release dosage forms

Modified release dosage forms are dosage forms that change the timing, rate or site of release of an active ingredient to achieve a clinical outcome not achievable by a non-modified release dosage form. A common form of modified release is sustained, prolonged or extended release, which slows down the release of an active ingredient so that one dosage form can provide release of an active ingredient over a longer time. This has the advantage of reducing the frequency of dosing. Reducing dosing frequency in humans is usually for a matter of hours as once-daily oral dosing is usually considered acceptable. The benefits of extended release dosage forms are even more pronounced in the treatment of livestock. Daily or even weekly dosing may be prohibitive for many livestock, particularly those needing to be herded for treatment. A treatment may only become viable with weekly, fortnightly, monthly, six-weekly, eight-weekly, two-monthly, or 10-weekly dosing. This is an extraordinary extension of release for a dosage form to achieve.

Extended release can be primarily due to the core. Extended release can be achieved with little extension of release profile arising from the casing or housing. Extended release can be due to significant extension effects arising from both the core and casing or housing. Extended release can be a release profile where the bolus is releasing methane inhibiting agent at least 20%, at least 30%, at least 40%, at least 50% of the maximal rate 24 h after the maximal rate is achieved. Extended release can be a release profile where the bolus is releasing methane inhibiting agent at least 20%, at least 30%, at least 40%, at least 50% of the maximal rate 1 week after the maximal rate is achieved. Extended release can be a release profile where the bolus is releasing methane inhibiting agent at least 20%, at least 30%, at least 40%, at least 50% of the maximal rate 1 month after the maximal rate is achieved. Extended release can be a release profile where the bolus is releasing methane inhibiting agent at least 20%, at least 30%, at least 40%, at least 50% of the maximal rate 6 months after the maximal rate is achieved.

Matrix systems, extended release coatings and other systems such as extended release particles within a matrix can be used to extend release of an active ingredient. The casing of the present disclosure functions as an extended release coating. The core of the present disclosure also has extended release properties. In preferred embodiments, the core of the present disclosure is a matrix system in which the active ingredient (as particles or granules optionally with non-extended release carrier) is homogeneously mixed into the core excipients. Alternatives that are contemplated by the disclosure include extended release particles containing active ingredient disbursed within binder, where the binder may or may not have additional extended release properties. Preferably the active ingredient is without excipient and directly and homogenously dispersed within the other components of the core.

In preferred embodiments, the matrix system in the core is hydrophobic (or water insoluble with minimal swelling). Optionally, the core is a blend of hydrophobic and hydrophilic ingredients, however the release characteristics are largely controlled by the hydrophobic ingredients.

In preferred embodiments, the casing is hydrophobic.

Zero-order release

Zero-order release of the active ingredient, which is a consistent release of active ingredient over the duration of release, is the goal of this type of dosage form.

First cellulosic polymer Preferably, the first cellulosic polymer is an extended release ingredient. Preferably, the first cellulosic polymer is hydrophobic. Preferably, the first cellulosic polymer is biodegradable. Preferably, the first cellulosic polymer is ethyl cellulose.

In some embodiments, the first cellulosic polymer is at least about 10%, about 12.5%, about 15%, about 17.5%, about 20%, about 22.5%, about 25%, about 30%, about 35%, or about 40% w/w of the core.

Optionally, the first cellulosic polymer is about 10 to about 45%, about 15 to about 45%, about 10 to about 40%, about 15 to about 35%, about 15 to about 25%, or about 20 to about 30% w/w of the core.

In some embodiments, the ratio of the first cellulosic polymer to casing in the bolus is about 0.5 to about 2.5 : 1 respectively by weight. In some embodiments, the ratio of the first cellulosic polymer to casing in the bolus is about 0.8 to about 2 : 1 respectively by weight. In some embodiments, the ratio of the first cellulosic polymer to casing in the bolus is about 0.8 to about 1.5 : 1 respectively by weight.

In some embodiments, the ratio of the active ingredient to the first cellulosic polymer in the bolus is about 2.0 to about 3.5 : about 0.5 to about 2.5 respectively by weight. In some embodiments, the ratio of the active ingredient to the first cellulosic polymer in the bolus is about 2.0 to about 3.5 : about 0.8 to about 2 respectively by weight. In some embodiments, the ratio of the active ingredient to the first cellulosic polymer in the bolus is about 2.5 to about 3 : about 0.8 to about 2 respectively by weight. In some embodiments, the ratio of the active ingredient to the first cellulosic polymer in the bolus is about 2.5 to about 3 : about 0.8 to about 1 .5 respectively by weight. In preferred embodiments, the ratio of the active ingredient to the first cellulosic polymer in the bolus is about 2:1 by weight.

In some embodiments, the ratio of the active ingredient to the first cellulosic polymer to the casing in the bolus is about 2.0 to about 3.5 : about 0.5 to about 2.5 : 1 respectively by weight. In some embodiments, the ratio of the active ingredient to the first cellulosic polymer to the casing in the bolus is about 2.0 to about 3.5 : about 0.8 to about 2 : 1 respectively by weight. In some embodiments, the ratio of the active ingredient to the first cellulosic polymer to the casing in the bolus is about 2.5 to about 3 : about 0.8 to about 2 : 1 respectively by weight. In some embodiments, the ratio of the active ingredient to the first cellulosic polymer to the casing in the bolus is about 2.5 to about 3 : about 0.8 to about 1.5 : 1 respectively by weight.

Integrity agent

An integrity agent is an excipient that improves the integrity of the core, for example, by reducing the hydrophobicity and/or hygroscopicity of the core. This can facilitate extended release, durability of the dosage form over time, or ease processing. This can also prevent excessive swelling of the core in the rumen. The integrity agent may alter one or more of the viscosity, hydrophobicity or hygroscopicity of the core. The integrity agent may also act as a channelling agent.

In some embodiments, the integrity agent is a second cellulosic polymer. Preferably, a hydrophilic polymer. Preferably, a biodegradable polymer.

In some embodiments, the integrity agent selected from the group consisting of hydroxypropyl methylcellulose, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), carrageenan, guar gum, xanthan gum, sodium alginate, locust bean gum, polyvinylpyrrolidone (PVP), polyvinylpyrrolidone-vinyl acetate co-polymer (PVP/VA), a polyacrylic acid and/or their co-polymer variants, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the integrity agent is hydroxypropyl methylcellulose.

In some embodiments, the integrity agent is at least about 10%, about 13%, about 16%, or about 19% w/w of the core.

Optionally, the integrity agent is about 5 to about 25%, about 10 to about 25%, about 15 to about 25%, about 20 to about 25%, about 5 to about 15%, or about 14 to about 20% w/w of the core.

In some embodiments, the ratio of the integrity agent to casing in the bolus is about 0.35 to about 1.75 : 1 respectively by weight. In some embodiments, the ratio of the integrity agent to casing in the bolus is about 0.6 to about 1 .5 : 1 respectively by weight. In some embodiments, the ratio of the integrity agent to casing in the bolus is about 0.6 to about 1.1 : 1 respectively by weight. In some embodiments, the ratio of the active ingredient to the integrity agent in the bolus is about 2.0 to about 3.5 : about 0.3 to about 1.8 respectively by weight. In some embodiments, the ratio of the active ingredient to the integrity agent in the bolus is about 2.0 to about 3.5 : about 0.5 to about 1 .5 respectively by weight. In some embodiments, the ratio of the active ingredient to the integrity agent in the bolus is about 2.5 to about 3 : about 0.5 to about 1.5 respectively by weight. In some embodiments, the ratio of the active ingredient to the integrity agent in the bolus is about 2.5 to about 3 : about 0.5 to about 1 respectively by weight.

In some embodiments, the ratio of the active ingredient to the integrity agent to the casing in the bolus is about 1 .4 to about 2.5 : about 0.5 to about 2.5 : 1 respectively by weight. In some embodiments, the ratio of the active ingredient to the integrity agent to the casing in the bolus is about 2.0 to about 3.5 : about 0.5 to about 1.5 : 1 respectively by weight. In some embodiments, the ratio of the active ingredient to the integrity agent to the casing in the bolus is about 2.5 to about 3 : about 0.5 to about 1.5 : 1 respectively by weight. In some embodiments, the ratio of the active ingredient to the integrity agent to the casing in the bolus is about 2.5 to about 3 : about 0.5 to about 1 : 1 respectively by weight.

In some embodiments, the ratio of the integrity agent to the first cellulosic polymer in the bolus is about 1 :1 to about 1 :2 respectively by weight. In some embodiments, the ratio of the integrity agent to the first cellulosic polymer in the bolus is about 0.8:1 to about 1 :2.5 respectively by weight. In some embodiments, the ratio of the integrity agent to the first cellulosic polymer in the bolus is about 1 :1. In some embodiments, the ratio of the integrity agent to the first cellulosic polymer in the bolus is about 1 :2 respectively by weight.

Second cellulosic polymer

In some embodiments, the second cellulosic polymer is selected from the group consisting of hydroxypropyl methylcellulose, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), carrageenan, guar gum, xanthan gum, sodium alginate, locust bean gum, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the second cellulosic polymer is hydroxypropyl methylcellulose. In some embodiments, the second cellulosic polymer is at least about 10%, about 13%, about 16%, or about 19% w/w of the core.

Optionally, the second cellulosic polymer is about 5 to about 25%, about 10 to about 25%, about 15 to about 25%, about 20 to about 25%, about 5 to about 15%, or about 14 to about 20% w/w of the core.

In some embodiments, the ratio of the second cellulosic polymer to casing in the bolus is about 0.35 to about 1 .75 : 1 respectively by weight. In some embodiments, the ratio of the second cellulosic polymer to casing in the bolus is about 0.6 to about 1.5 : 1 respectively by weight. In some embodiments, the ratio of the second cellulosic polymer to casing in the bolus is about 0.6 to about 1.1 : 1 respectively by weight.

In some embodiments, the ratio of the active ingredient to the second cellulosic polymer in the bolus is about 2.0 to about 3.5 : about 0.3 to about 1 .8 respectively by weight. In some embodiments, the ratio of the active ingredient to the second cellulosic polymer in the bolus is about 2.0 to about 3.5 : about 0.5 to about 1 .5 respectively by weight. In some embodiments, the ratio of the active ingredient to the second cellulosic polymer in the bolus is about 2.5 to about 3 : about 0.5 to about 1 .5 respectively by weight. In some embodiments, the ratio of the active ingredient to the second cellulosic polymer in the bolus is about 2.5 to about 3 : about 0.5 to about 1 respectively by weight.

In some embodiments, the ratio of the second cellulosic polymer to the integrity agent to the casing in the bolus is about 1.4 to about 2.5 : about 0.5 to about 2.5 : 1 respectively by weight. In some embodiments, the ratio of the active ingredient to the second cellulosic polymer to the casing in the bolus is about 2.0 to about 3.5 : about 0.5 to about 1.5 : 1 respectively by weight. In some embodiments, the ratio of the active ingredient to the second cellulosic polymer to the casing in the bolus is about 2.5 to about 3 : about 0.5 to about 1.5 : 1 respectively by weight. In some embodiments, the ratio of the active ingredient to the second cellulosic polymer to the casing in the bolus is about 2.5 to about 3 : about 0.5 to about 1 : 1 respectively by weight.

In some embodiments, the ratio of the second cellulosic polymer to the first cellulosic polymer in the bolus is about 1 :1 to about 1 :2 respectively by weight. In some embodiments, the ratio of the second cellulosic polymer to the first cellulosic polymer in the bolus is about 0.8:1 to about 1 :2.5 respectively by weight. In some embodiments, the ratio of the second cellulosic polymer to the first cellulosic polymer in the bolus is about 1 :1 . In some embodiments, the ratio of the second cellulosic polymer to the first cellulosic polymer in the bolus is about 1 :2 respectively by weight.

Carrier

A carrier as used herein is a compound that can be mixed with an active ingredient without changing the chemical structure of the active ingredient. Preferably, the carrier when used in a bolus of the disclosure delays the release of the active ingredient from the bolus.

A range of substances may be suitable for use as a carrier in the boluses of the present disclosure and the following examples are not limiting. Numerous large molecules and/or particles dispersible or miscible in a haloform with branching or surface modification able to associate with a haloform are suitable. For instance, the carrier may be selected from the list of waxes, myristic acid, stearic acid, stearyl alcohol, cetyl alcohol, cetostearyl alcohol or a combination thereof. The carrier may be a waxy substance, for example, the carrier may be selected from the list of bee’s wax, paraffin wax, PEG4000, Carnauba, castor wax, Candellila, Jojoba wax, or Lanolin wax or a combination thereof. The carrier may comprise a mixture of two or more components, such as at least one relatively polar substance with a relatively non-polar substance. As a result, the overall polarity of the carrier may be adjusted to achieve the desired affinity for the active ingredient. This can be used to achieve a desired release rate for the active ingredient. For instance, in some forms the carrier may include a mixture of paraffin wax (a mixture of alkanes with no polar functional groups) and castor wax and/or carnauba wax (which have a relatively high amount of polar functional groups).

In some embodiments, the carrier includes one or more biodegradable polymers. In some embodiments, the carrier consists of one or more biodegradable polymers. In some embodiments, the carrier includes two or more biodegradable polymers. In some embodiments, the carrier consists of two or more biodegradable polymers. In some embodiments, the carrier does not include a wax. In some embodiments, the carrier includes one or more materials selected from the list consisting of polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co-adipate (PBSA), polylactic acid (PLA), poly-lactic acid, poly-d-lactic acid, poly-L-lactic acid, poly-D,L-lactic acid (PDLLA), poly-lactide-co-glycolide, lignin, polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D-lactide) (TALC PDLA), Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), epoxy-based chain extenders, magnesium silicate, cellulosic materials, ethyl cellulose, hydroxypropyl methyl cellulose (HPMC), fumed silica, gelatin, wax, castor wax, paraffin wax, silica, microcrystalline wax, methyl cellulose, starch, polyethylene glycol, polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, soluplus, Poly(acrylic acid) , poly(vinylpyrrolidone), poly(vinyl alcohol), poly(acrylamide), poly(2-hydroxypropyl methacrylamide), poly(N,N-dimethylacrylamide), poly([2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide), poly(2- (methacryloyloxy)ethyl phosphorylcholine), poly(carboxybetaine methacrylamide), polyethylene glycol), polyethylene imine), poly(sarcosine), poly(2-methyl-2-oxazoline), polyamino esters, polyester amides, polyphosphoesters, poly(l-lysine), poly(l-proline) , polyphosphazenes, dextran, sodium alginate, gelatin, agarose, carrageenan, gellan, xantham gum, urea, sucrose, derivatives thereof, combinations thereof, and co-polymers thereof. In some embodiments, the carrier includes one or more materials selected from the list consisting of polycaprolactone (PCL), ethyl cellulose (EC), hydroxypropyl methylcellulose (HPMC), fumed silica/aerosil, castor wax, paraffin, stearic acid, microcrystalline wax, beeswax, polyethylene glycol (PEG), sodium starch glycolate, croscarmellose sodium, crospovidone, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), carrageenan, guar gum, xanthan gum, sodium alginate, locust bean gum, polyvinylpyrrolidone (PVP), polyvinylpyrrolidone-vinyl acetate co-polymer (PVP/VA), a polyacrylic acid and/or their co-polymer variants, polyisobutylene, ethyl vinyl acetate (EVA), a functional wax with a melting point less than about 120 °C, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the carrier includes one or more biodegradable polymers selected from the list above, combinations thereof, combinations with talc thereof, and co-polymers thereof.

In some embodiments, the carrier includes one or more materials selected from the list consisting of carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), carrageenan, guar gum, xanthan gum, sodium alginate, locust bean gum, polyvinylpyrrolidone (PVP), polyvinylpyrrolidone-vinyl acetate co-polymer (PVP/VA), a polyacrylic acid and/or their co-polymer variants, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the carrier includes one or more materials selected from the list consisting of polyisobutylene, ethyl vinyl acetate (EVA), a functional wax with a melting point less than about 120 °C, combinations thereof, combinations with talc thereof, and co-polymers thereof.

In some embodiments, the carrier includes one or more cellulose derivative, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the carrier consists of one or more cellulose derivative, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the carrier includes ethyl cellulose, hydroxypropyl methylcellulose, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the carrier consists of ethyl cellulose, hydroxypropyl methylcellulose, combinations thereof, combinations with talc thereof, and co-polymers thereof. In some embodiments, the carrier includes ethyl cellulose. In some embodiments, the carrier includes hydroxypropyl methylcellulose.

In some embodiments, the ethyl cellulose is about 10% to about 45%, about 10% to about 40%, about 15% to about 45%, about 15% to about 40%, about 15% to about 35%, about 15% to about 30%, about 15% to about 25%, or about 20% to about 30% w/w of the core. In some embodiments, the ethyl cellulose is about 20.1 % w/w of the core. In some embodiments, the ethyl cellulose is about 27.3%, about 15%, about 17.5%, about 19.5%, about 18.2%, about 20.5%, about 20.1 %, about 21.6%, about 21.3%, about 22.5%, about 21.5%, about 24.3%, about 25%, about 22.5%, about 30%, about 27.3%, about 39%, about 40%, or about 42% w/w of the core.

In some embodiments, the hydroxypropyl methylcellulose is about 5 to about 25% about 10% to about 30%, about 10% to about 25%, about 15 to about 25%, about 20 to about 25%, about 5 to about 15%, or about 12% to about 20% w/w of the core. In some embodiments, the hydroxypropyl methylcellulose is about 14.3% w/w of the core. In some embodiments, the hydroxypropyl methylcellulose is about 19.6% w/w of the core. In some embodiments, the hydroxypropyl methylcellulose is about 20%, about 22.5%, about 15%, about 25%, about 17.5%, about 23.3%, about 19.6%, about 18.1%, about 20.3%, about 21 .5%, about 17.3%, about 14.3% or about 5% w/w of the core.

In some embodiments, the ethyl cellulose is about 48.0 to about 49.5% w/w ethoxyl basis.

In some embodiments, the ethyl cellulose has a viscosity of about 4 cP, 7 cP, 10 cP, 20 cP, about 45 cP or about 100 cP at 5% w/w (80:20 Toluene/Ethanol)solution at 25 °C. In some embodiments, the ethyl cellulose has a viscosity of about 6 to about 49 mPa.s at 5% w/w (80:20 Toluene/Ethanol) solution at 25 °C. In some embodiments, the ethyl cellulose has a viscosity of about 6 to about 8 mPa.s at 5% w/w (80:20 Toluene/Ethanol) solution at 25 °C. In some embodiments, the ethyl cellulose has a viscosity of about 41 to about 49 mPa.s at 5% w/w (80:20 Toluene/Ethanol) solution at 25 °C.

In some embodiments, the hydroxypropyl methylcellulose of the carrier is E3 LV (hydroxypropoxyl content 7.0-12.0 %, methoxyl content 19.0-24.0 %, apparent viscosity 2.4-3.6 mPa.s), E5 LV (hydroxypropoxyl content 7.0-12.0 %, methoxyl content 28.0-30.0 %, apparent viscosity 4.0-6.0 cps), E6 LV (hydroxypropoxyl content 7.0-12.0 %, methoxyl content 28.0-30.0 %, apparent viscosity 4.8-7.2 cps), E15 LV (hydroxypropoxyl content 7.0-12.0 %, methoxyl content 28.0-30.0 %, apparent viscosity 12.0-18.0 mPa.s), E50 LV (hydroxypropoxyl content 7.0-12.0 %, methoxyl content 28.0-30.0 %, apparent viscosity 40.0-60.0 mPa.s), and K100 LV (hydroxypropoxyl content 4.0-12.0 %, methoxyl content 19.0-24.0 %, apparent viscosity 80.0-120.0 mPa.s), or combinations thereof. The apparent viscosities listed above are measured according to the current USP (2% aqueous solution in water at 20 °C).

In some embodiments, the hydroxypropyl methylcellulose has a viscosity from about 3 to about 100,000 cP (mPa-s) measured in 2 % w/w aqueous solution at 20 °C. In some embodiments, the hydroxypropyl methylcellulose has a viscosity of about 100,000 cP (mPa-s) measured in 2 % w/w aqueous solution at 20 °C. In some embodiments, the hydroxypropyl methylcellulose has a viscosity from about 75,000 to about 140,000 mPa.s measured in 2 % w/w aqueous solution at 20 °C. In some embodiments, the hydroxypropyl methylcellulose has a methoxyl content from about 19% to about 24%. In some embodiments, the hydroxypropyl methylcellulose has a hydroxypropyl content from about 7% to about 12%. In some embodiments, the hydroxypropyl methylcellulose has a methoxyl content from about 19% to about 24%, and a hydroxypropyl content from about 7% to about 12%.

In some embodiments, the hydroxypropyl methylcellulose is E3 LV, E5 LV, E6 LV, E15 LV, E50 LV, and K100 LV, or combinations thereof.

In some embodiments, the carrier comprises a channelling agent. Channelling agents are substances that are soluble in the gastrointestinal tract and leach from the formulation, leaving capillaries through which the active ingredient may diffuse in order to be released. In some embodiments, the channelling agent is one or more of a hydrophilic polymer, polyol and liquid. In some embodiments, the channelling agent is a hydrophilic polymer and/or polyol. In some embodiments, the channelling agent is a liquid. In some embodiments, the channelling agent is selected from the list consisting of alginate, an osmotic agent (such as NaCI, mannitol), a phospholipid (such as lecithin), an alcohol or derivative (such as glycerol, triacetin), a polyethylene glycol (PEG), sorbitol, citric acid, sodium bicarbonate, triacetin, ethyl oleate, or suitable polymers such as sodium starch glycolate, croscarmellose sodium and crospovidone. In some embodiments, the channelling agent is selected from the group consisting of water, an alcoholic solvent (such as ethanol), a polyol (such as glycerol (triol), propylene glycol (diol), ethylene glycol (diol) and combinations thereof), and combinations thereof. In some embodiments, the channelling agent is water. In some embodiments, the channelling agent is ethanol.

In some embodiments, the channelling agent is about 2% to about 20%, about 2% to about 15% w/w, 2% to about 10%, 5% to about 15% w/w of the core. In some embodiments, the channelling agent is about 2.7%, about 5%, or about 15% w/w of the core. In some embodiments, the carrier does not comprise a channeling agent.

In some embodiments, the carrier comprises a moderating agent. Moderating agents are substances that alter the active ingredient’s affinity to the carrier such that peak release is reduced and/or the lag time in release is increased. Preferably, the moderating agent decreases the initial burst release and helps achieve a more sustainable zero order release. In some embodiments, the moderating agent is a liquid. In some embodiments, the moderating agent is DMSO, a medium chain triglyceride (medium chain = an aliphatic tail of 6-12 carbon atoms), a propylene glycol diester of saturated plant fatty acids with chain lengths of C6-C12, a non-ionic surfactant (such as polysorbate, sorbitan fatty acid ester), and combinations thereof.

In some embodiments, the moderating agent is about 2% to about 20%, about 2% to about 15% w/w, 2% to about 10%, 5% to about 15% w/w of the core. In some embodiments, the moderating agent is about 2.7%, about 5%, or about 15% w/w of the core. In some embodiments, the carrier does not comprise a moderating agent.

In some embodiments, the carrier does not include hydrophobic fumed silica. In some embodiments, the carrier does not include silica. In some embodiments, the carrier includes hydrophilic silica.

In some embodiments, the core does not include an additional excipient. In some embodiments, the core does not include a wax.

In some embodiments, the carrier does not comprise a compound having the structure of formula (I) or (II), or a pharmaceutically acceptable salt thereof, wherein

(1 ) each of Y1, Y2 and Y3 is independently selected from the group consisting of Br and Cl;

(2) L is CH2, O, NH, or absent (preferably L is O or NH); and

(3) R is an optionally substituted group selected from the group consisting of OH, Ci -isalkyl, Ci- alkoxy and Ci-8alkyl-C(O)OH; wherein if R is substituted, then it is substituted by one or more groups independently selected from the group consisting of C-i-salkyl, -OH, halogen, NH2, -C(O)OH, -COCi-4alkyl, -C(O)OCi-4alkyl, -NO2, and more particularly is substituted with one or more groups selected from the group consisting of Ci-₂alkyl, -OH, halogen, NH₂, -C(O)OH, -COMe, and -C(O)OMe.

In some embodiments, the carrier does not comprise a compound having the structure of formula (la),

Y₂ — c I¹ — z

^Y> (la) or a pharmaceutically acceptable salt thereof, wherein each of Y-i, Y₂ and Y3 is independently selected from the group consisting of Br and Cl; and

Z is:

(1 ) a group that will be cleaved off the carbon atom shown in formula la, such that Z is replaced by a hydrogen atom when the composition is exposed to the environment inside the rumen of a ruminant animal; or

(2) a group that will be cleaved off the carbon atom shown in formula la, such that Z is replaced by a hydrogen atom when compound la is contacted with a second activating compound that is comprised in said composition, wherein the second activating compound will come into contact with the compound la only when the composition is exposed to the environment inside the rumen of a ruminant animal.

Optionally, the at least one carrier is about 5 to about 80%, about 10 to about 70%, about 20 to about 60%, about 30 to about 50% w/w of the core.

Core

In some embodiments, the core is of uniform composition. For example, the core does not include a region that is excipient only without dispersed active ingredient. In some embodiments, the core is not connected to any additional internal element of the bolus designed to facilitate release of the active ingredient. In some embodiments, the core is not contacted by any additional internal element of the bolus designed to facilitate release of the active ingredient.

Casing

As used herein, casing refers refer to a feature that encases, completely or partially, the core. The casing may be a housing. A housing is an exterior feature that protects an interior. Often casing and housing are synonymous in the context of a bolus. Optionally, the casing is coated onto the core. Optionally, the casing is made and then filled with core.

In some embodiments, the casing or housing has a Shore D hardness of at least 40. In some embodiments, the casing or housing has a Shore D hardness of less than 70. In some embodiments, the casing or housing has a Shore D hardness of 40 to 70.

In some embodiments, the casing encapsulates the core. In some embodiments, the casing substantially encapsulates the core ie the core is not fully encapsulated but sufficiently surrounded by casing to retain the core within the casing. A substantially encapsulated core has about 70 to about 99%, about 80 to about 99%, about 85 to about 99% or about 90 to about 99% of the surface area of the core covered by the casing.

In some embodiments, the casing does not comprise an opening. In some embodiments, release of the compound for release in the rumen (active ingredient) via the casing is consistent across the regions where the core directly contacts the casing (ie where there is no densifier between the core and casing).

In some embodiments, the casing includes one or more biodegradable polymers. In some embodiments, the casing consists of one or more biodegradable polymers. In some embodiments, the casing does not include a non-biodegradable polymer. In some embodiments, the casing includes one or more non-biodegradable polymers, including Polyvinyl chloride (PVC), polyethylene terephthalate (PET), Buna-S, nylon, polyvinyl butyral, polyethylene (low [LDPE], medium [MDPE], high [HDPE] or ultra high molecular weight [UHMWPE]), polypropylene (PP) and combinations thereof. In some embodiments, the casing includes one or more non-biodegradable polymers, including polyethylene (including low-density polyethylene (LDPE, medium density polyethylene (MDPE), high-density polyethylene (HDPE), and combinations thereof), polypropylene (PP) and combinations thereof. In some embodiments, the casing includes one or more non-biodegradable polymers, including high-density polyethylene (HDPE), polypropylene (PP) and combinations thereof.

In alternate embodiments, the casing includes one or more hydrophobic polymers. Optionally, the casing includes one or more hydrophobic biodegradable polymers. In alternate embodiments, the casing consists of one or more hydrophobic polymers. Optionally, the casing consists of one or more hydrophobic biodegradable polymers.

In some embodiments, the casing includes one or more ester-based polymers.

In some embodiments, the casing includes one or more polymers selected from the list consisting of Polyvinyl chloride (PVC), polyethylene terephthalate (PET), Buna-S, nylon, polyvinyl butyral, polyethylene (low [LDPE], medium [MDPE], high [HDPE] or ultra high molecular weight [UHMWPE]), polypropylene (PP), polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co-adipate (PBSA), polylactic acid (PLA), poly-D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene- acrylic copolymer (such as Joncryl®), talc-filled poly(D-lactide) (TALC PDLA), Poly(3- hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof. In some embodiments, the casing includes one or more polymers selected from the list consisting of high-density polyethylene (HDPE), polypropylene (PP), polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co-adipate (PBSA), polylactic acid (PLA), poly-D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D-lactide) (TALC PDLA), Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof. In some embodiments, the casing consists of one or more polymers selected from the list consisting of polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co-adipate (PBSA), polylactic acid (PLA), poly-D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D-lactide) (TALC PDLA), Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof. In some embodiments, the casing includes one or more polymers selected from the list consisting of Polyvinyl chloride (PVC), polyethylene terephthalate (PET), Buna-S, nylon, polyvinyl butyral, polyethylene (low [LDPE], medium [MDPE], high [HDPE] or ultra high molecular weight [UHMWPE]), polypropylene (PP), combinations thereof, and co-polymers thereof. In some embodiments, the casing includes one or more polymers selected from the list consisting of high-density polyethylene (HDPE), polypropylene (PP), combinations thereof, and co-polymers thereof. In some embodiments, the casing includes one or more polymers selected from the list consisting of polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co-adipate (PBSA), polylactic acid (PLA), poly- D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D-lactide) (TALC PDLA), Poly(3- hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA),, combinations thereof, and co-polymers thereof. In some embodiments, the casing consists of one or more polymers selected from the list consisting of polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co-adipate (PBSA), polylactic acid (PLA), poly- D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D-lactide) (TALC PDLA), Poly(3- hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof.

In some embodiments, the casing includes one or more of poly lactic acid (PLA), poly glycolic acid (PGA), poly lactic glycolic acid (PLGA), polypropylene, Polycaprolactone (PCL), poly(d-lactic acid) (PDLA), Polybutylene succinate (PBS), Polybutylene adipate terephthalate (PBAT), SLA polymer or one or more thermoset polymers and/or resins, ABS, combinations thereof, and co-polymers thereof. In some embodiments, the casing includes one or more of polylactic acid (PLA), poly-butylene succinate co-adipate (PBSA), poly-butylene succinate (PBS), polyhydroxybutyrate-co- hydroxy valerate, poly vinyl acetate (PVA), Polybutylene adipate terephthalate (PBAT), polycaprolactone (PCL), wood flour and cellulosic materials, ethyl cellulose and hydroxypropyl methyl cellulose, combinations thereof, and co-polymers thereof.

In some embodiments, the casing includes one or more polymers selected from the list consisting of polylactic acid, polybutylene adipate terephthalate, combinations thereof, and co-polymers thereof. In some embodiments, the casing consists of one or more polymers selected from the list consisting of polylactic acid, polybutylene adipate terephthalate, combinations thereof, and co-polymers thereof.

In some embodiments, the PLA:PBAT ratio is from about 95:5 to about 70:30 wt/wt, from about 95:5 to about 80:20 wt/wt, or from about 95:5 to about 85:15 wt/wt. In some embodiments, the PLAPBAT ratio is about 90:10 wt/wt.

Blends of such substances can be particularly advantageous. For instance, mixing/blending a polybutylene polymer such as PBAT with PLA increases the plasticity and strength of the casing compared to a casing made of PLA alone, while preserving the biodegradability of the casing material. This stability improving effect is particularly beneficial when using for instance haloforms as a methane inhibiting agent, because such compounds can otherwise promote brittleness of the casing material. Furthermore, the use of a polybutylene polymer/PLA blend compared to PLA alone, improves the durability of the casing and reduces the risk of fracturing under mechanical stress, such as when placed into the rumen of an animal.

The components used or mixed to form the casing material may be selected according to their suitability regarding the use for forming the bolus casing. Upon heating for shaping the bolus casing the composition should not become too viscous for 3D printing or injection moulding and blending of two or more polymers should result in a homogeneous mixture without extensive bubbles formation. 3D printing includes stereolithography (SLA) and digital light processing (DLP).

The casing of the bolus may for instance comprise biodegradable and/or non- biodegradable materials, but preferably comprises biodegradable polymers. Such materials may be synthetic, or naturally, or essentially naturally derived. It is preferred that materials are selected from biodegradable polymers. Examples of such polymers include, without limitation, poly lactic acid (PLA), polybutylene terephthalate (PBT), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS) and/or polybutylene succinate adipate (PBSA). Biodegradability allows repeated administration of boluses, while preventing the accumulation of bolus materials in the ruminant animal’s body, since the bolus components can be at least partially or even fully degraded in the rumen milieu. Nevertheless, it is understood that even if a bolus casing is biodegradable, it will not fully degrade to a degree that the bolus breaks down for the duration of at least 7 days when kept in the rumen for this time. Suitable non-biodegradable polymers include Polyvinyl chloride (PVC), polyethylene terephthalate (PET), Buna-S, nylon, polyvinyl butyral, polyethylene (low [LDPE], medium [MDPE], high [HDPE] or ultra high molecular weight [UHMWPE]), polypropylene (PP), combinations thereof, and co-polymers thereof. Suitable non-biodegradable polymers include high-density polyethylene (HDPE), polypropylene (PP), combinations thereof, and co-polymers thereof.

Accordingly, the casing for any bolus described herein may be configured to have sufficient structural integrity to remain intact for a predetermined period of time. In a preferred embodiment, the casing may be configured to degrade over a predetermined period of time. A predetermined period of time may mean the period of time over which the methane inhibiting agent is to be released to the animal. In a particularly preferred embodiment, the predetermined period of time may be at least two months, preferably six months, and more preferably 12 months.

Alternatively, the casing may be made from one or more non-adsorbent materials, i.e. materials into which, or through which, the methane inhibiting agent does not migrate. Using a non-absorbent material for the casing can assist with controlling the rate of release of the methane inhibiting agent(s), for instance in a bolus comprising one or more openings, in a bolus with a casing which is able to form one or more openings or in an open-ended bolus. For instance, in these embodiments, the concentration of the methane inhibiting agent(s) in the core is not decreased by their absorption into/or passing through the casing material.

In some embodiments, at least the non-closing region portion of the casing is uniform. Optionally, the active ingredient migrates through the casing in use.

In some embodiments, the casing comprises one or more excipients. In a preferred embodiment the one or more excipients includes a plasticizer, hardener and/or colorant. As used herein, “hardener” refers to a cross-linking agent and/or an excipient whose inclusion increases the Shore D hardness of the casing.

In some embodiments, the casing further comprises a compound selected from a nucleating agent or stabilizer. In some embodiments, the casing does not comprise a nucleating agent and/or a stabilizer. The thickness of the casing may be selected to contribute to the rate of release of the methane inhibiting agent, i.e. a relatively thicker casing will have a relatively slower release rate than a relatively thinner casing. This is particularly the case if the casing material is permeable for the methane inhibiting agent. In some embodiments, the casing has a material thickness less than about 2 mm, preferably a material thickness in the range of about 0.3-1 .8 mm, and more preferably a material thickness in the range of about 0.3-1.5 mm. In some embodiments, the casing has a material thickness less than about 1.5 mm, less than about 1.3 mm, or less than about 1 mm. In some embodiments, the casing has a material thickness greater than about 0.8 mm, greater than about 1 mm or greater than about 1.1 mm. In some embodiments, the casing has a material thickness of about 0.9 mm. In some embodiments, the casing has a material thickness of about 1 .2 mm. In some embodiments, the casing has a material thickness of about 1.5 mm. For boluses comprising a casing with one or more openings, thicker casings may be applicable, such as up to about 5 mm of casing wall thickness.

In some embodiments, the casing is not configured to form one or more openings in at least part of the casing when exposing the casing to a temperature of between 35 °C and 45 °C, allowing the methane inhibiting agent to exit the bolus through said opening or openings. In some embodiments, the casing is permeable and/or can become permeable to active ingredient before exposing the casing to a temperature of between 35 °C and 45 °C.

Optionally, the core and casing have a ratio of about 3 to about 6 : 1 , about 4 to about 5 : 1 or about 4.6 : 1 by weight.

Preferably, the casing material is compatible with waste disposal regulations that apply to slaughter facilities. The casing material can generally include any material that is non-toxic when administered to the rumen of an animal. It is of particular relevance that any food animals will result in non-toxic foods (meat or milk) following exposure to the materials in the bolus. The casing material is further preferably sufficiently thick (wall thickness) so that it resists the mechanical stress and abrasive forces in a rumen.

The casing is shaped to fit with the core and any other components in the bolus such that there are no air pockets in the bolus. In some embodiments, the casing is uniform ie without specific portions designed to speed or slow release. In another embodiments, the closed region is uniform ie without specific portions designed to speed or slow release (other than the sealed region).

Active ingredient

As used herein, an active ingredient is an ingredient which interacts with the biology of a living organism to exhibit one or more effects such as treatment or prevention of a condition, for example, inhibiting a metabolic process such as methanogenesis in relevant ruminal organisms when administered to the rumen of a ruminant in a therapeutically effective amount. In some embodiments, the active ingredient is a methane inhibitor. A “methane inhibitor” as used herein is an active agent, such as a compound or compound mixture, which is capable of inhibiting or reducing the production of methane gas in the rumen of a ruminant animal. In some embodiments, the methane inhibitor is a haloform including a mixed haloform. Preferably the haloform is selected from chloroform, bromoform, iodoform, or combinations thereof; more preferably, bromoform.

Optionally, the active ingredient is liquid. Alternatively, the active ingredient is solid. In some embodiments, the active ingredient is volatile. Alternatively, the active ingredient is non-volatile. In some embodiments, the active ingredient is hydrophobic.

In some embodiments, the active ingredient has a molar mass of 100 to 600 g/mol, 100 to 500 g/mol, 100 to 400 g/mol, 100 to 300 g/mol, 200 to 500 g/mol, 200 to 400 g/mol or 200 to 300 g/mol.

In some embodiments, the active ingredient has a logP of about 1 to about 4. In some embodiments, the active ingredient has a logP of 1 .6 to 3.2.

In some embodiments, the active ingredient does not include protein or nucleic acid, for example, does not include a virus

Optionally, the active ingredient or haloform is about 20 to about 90%, about 30 to about 80%, about 40 to about 80%, about 50 to about 70% or about 60% w/w of the core.

Hydrophobicity In some embodiments, one or more of the casing, first, and second cellulosic polymer are hydrophobic. The skilled person will appreciate that hydrophobicity may be measured through analysis of water contact angles using a goniometer. In some embodiments, the difference in static water contact angle between one or more of the casing, first, and second cellulosic polymer is at least about 60°, at least about 50°, at least about 40°, at least about 30°, at least about 20°, at least about 15°, at least about 10°, or at least about 5° at 20 °C.

Ruminant

In some embodiments, the bolus is for or suitable for administration to the rumen of a ruminant animal. In some embodiments, the ruminant is bovine, ovine, caprine or cervine. In some embodiments, the ruminant is bovine. In some embodiments, the ruminant is ovine.

Bolus

Broadly, a bolus is a dosage form having a discrete dosage of a substance such as a medicine, supplement or metabolism adjuster. In the context of this disclosure, a bolus may be solid, semisolid, or a combination thereof. The bolus may also be a combination of liquid with solid, semisolid, or a combination thereof provided the liquid is encased in solid, semisolid, or a combination thereof. The semi-solid may be a blend of a liquid with a solid or semisolid substance. The bolus is usually used for oral administration to the gastrointestinal tract of the animal, preferably to the rumen of a ruminant. The bolus is swallowed but may be administered with the assistance of a bolus gun or balling gun, several versions of which are commercially available. The shape of a bolus can vary but round, oblong or capsule shapes are common. The size of the bolus can vary as is suitable for administration to the relevant animal. A bolus can be hard or of softer more malleable consistency. The bolus may be in the form of a pill, capsule or tablet so long as the pill, capsule or tablet could be administered using a bolus or balling gun as opposed to the smaller pills, capsules or tablets sized for inclusion into animal feeds.

In a preferred embodiments as depicted in Figure 8, the bolus of the disclosure (100) includes a casing (101 ) that encapsulates or substantially encapsulates the core (102). The casing further comprises a closed region (103). The casing is optionally about 0.5 to about 2.0 mm thick, about 0.8 to about 2.0 mm thick, about 0.8 to about 1 .8 mm thick, about 0.9 to about 1 .8 mm thick, about 1 .0 to about 1 .8 mm thick, about 0.8 to about 1 .5 mm thick, about 0.9 to about 1 .5 mm thick, about 1 .0 to about 1 .5 mm thick or about 1 .2 mm thick. The casing is optionally about 5 to about 15%, about 6 to about 12%, about 6 to about 10%, about 7 to about 15%, about 7 to about 12%, about 7 to about 10% or about 8% w/w of the bolus. The core is optionally about 20 to about 55%, about 25 to about 50%, about 30 to about 45%, about 35 to about 40% w/w or about 37% w/w of the bolus. The bolus further comprises a densifier (104), the densifier separates the closed region of the casing from the core. The densifier is optionally about 30 to about 75%, about 40 to about 70%, about 45 to about 65%, about 50 to about 60%, about 55% w/w of the bolus.

In some embodiments, the bolus comprises a therapeutically effective amount of an active ingredient and:

• about 5% to about 15% (w/w) casing;

• about 20 to about 55 (w/w) core; and

• about 30 to about 75 (w/w) densifier.

Release and duration

In some embodiments, the bolus of the disclosure comprises the methane inhibitor bromoform and is adapted to reach a maximum release rate of approximately 0.1 - approximately 0.5 g per day, and more preferably approximately 0.2 g per day. Such release rates may provide a sustained release of haloforms, such as bromoform. A bolus with such release rate is for instance suitable for use in cattle and sheep.

In some embodiments, the bolus may be adapted to exhibit a release rate of between 0.02 g and 2 g per day into the rumen, preferably a release rate of approximately 0.1 to 0.5g of bromoform per day. When a bolus exhibits such release rates for the methane inhibiting agent (e.g. a haloform, such as bromoform), this can reduce methane production. The rate of release of the methane inhibiting agent into the rumen may increase over time, i.e. the rate of release starts from zero on administration to the animal and increases to a maximum due to several factors. However, the foregoing should not be seen as limiting, and other release rates are envisaged as within the scope of the present disclosure.

In some embodiments, the bolus is formulated to administer haloform to the rumen of the ruminant animal for at least about 8 weeks after administration. In some embodiments, the bolus is formulated to administer haloform to the rumen of the ruminant animal for at least about 20 weeks after administration. In some embodiments, the bolus is formulated to administer haloform to the rumen of the ruminant animal for at least about 6 weeks after administration. In some embodiments, the bolus is formulated to administer haloform to the rumen of the ruminant animal for at least about 14 weeks after administration.

In some embodiments, the release rate of the methane inhibiting agent is increased by at least 5%, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90% or at least 95% when exposing the bolus to the rumen of a living animal, relative to the release rate on the same day after exposure of the bolus to phosphate buffer (pH: 6.5, 0.02 M) at 20 °C without agitation for the same length of time.

In some embodiments, the release rate of the methane inhibiting agent is increased by at least 5%, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90% or at least 95% when exposing the bolus to the rumen of a living animal, relative to the release rate on the same day after exposure of the bolus to phosphate buffer (pH: 6.5, 0.02 M) at 25 °C without agitation for the same length of time.

In some embodiments, the release rate of the methane inhibiting agent is increased by at least 5%, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90% or at least 95% when exposing the bolus to the rumen of a living animal, relative to the release rate on the same day after exposure of the bolus to phosphate buffer (pH: 6.5, 0.02 M) at 30 °C without agitation for the same length of time. In some embodiments, the difference is release rate is the release rate for the seventh day, fourteenth day, thirtieth day or sixtieth day after exposing the bolus to the rumen of a living animal, relative to the release rate on the same day after exposure of the bolus to phosphate buffer (pH: 6.5, 0.02 M) at the defined temperature without agitation for the same length of time.

In some embodiments, the release rate of the methane inhibiting agent is increased by at least 5%, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90% or at least 95% when exposing the bolus to phosphate buffer (pH: 6.5, 0.02 M) at 40 °C without agitation, relative to release rate on the same day after exposure of the bolus to phosphate buffer (pH: 6.5, 0.02 M) at 20 °C without agitation for the same length of time.

In some embodiments, the release rate of the methane inhibiting agent is increased by at least 5%, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90% or at least 95% when exposing the bolus to phosphate buffer (pH: 6.5, 0.02 M) at 40 °C without agitation, relative to release rate on the same day after exposure of the bolus to phosphate buffer (pH: 6.5, 0.02 M) at 25 °C without agitation for the same length of time.

In some embodiments, the release rate of the methane inhibiting agent is increased by at least 5%, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90% or at least 95% when exposing the bolus to phosphate buffer (pH: 6.5, 0.02 M) at 40 °C without agitation, relative to release rate on the same day after exposure of the bolus to phosphate buffer (pH: 6.5, 0.02 M) at 30 °C without agitation for the same length of time.

In some embodiments, the difference is release rate is the release rate for the seventh day, fourteenth day, thirtieth day or sixtieth day after exposing the bolus to phosphate buffer (pH: 6.5, 0.02 M) at 40 °C without agitation, relative to the release rate on the same day after exposure of the bolus to phosphate buffer (pH: 6.5, 0.02 M) at the defined temperature without agitation for the same length of time.

Release rate out of the bolus can be measured by any suitable means, for instance GC-FID analysis of the surrounding mixture. GC-FID is suitable for quantifying bromoform, and thus quantifying permeability of a housing/casing to bromoform. Samples from the rumen of living animals may be collected from fistulated animals.

Retention in the rumen

The length of time that the bolus is retained in the rumen can be increased by formulating the bolus to have a density greater than that of the fluid in the rumen. One way of achieving this outcome is to include a densifier in the bolus. A densifier is a component that increases the density of the bolus. The densifier can be a metal powder such as ZnO, metal balls such as steel balls or other dense material that is suitable for inclusion in a bolus. Preferably, the densifier increases the density of the bolus to a density greater than 1 .0 g/cm³. In some embodiments, the densifier is a densifier matrix comprising densifier and at least one veterinary acceptable excipient. Optionally, the densifier matrix includes a matrix material more hydrophobic than the at least one carrier. Optionally, the densifier matrix includes a wax. Optionally, the densifier is either dispersed in the core, in or on the casing, or separate to the core and casing (preferably within the casing). Optionally, the densifier is about 30 to about 75% w/w of the bolus, preferably about 45 to about 65%, or about 55% w/w of the bolus.

An alternative approach to increasing the length of time the bolus is in the rumen is to ensure the bolus is too large to pass from the rumen. This can include attaching a further component to the bolus that increases the cross-section of the bolus to at least 4 cm², at least 5 cm², at least 6 cm² in area at, at least, one point. The centre of the crosssection does not need to be solid.

Diffusion testing

Diffusion testing is a common technique for assessing the nature of a dosage form in vitro. The diffusion test results are often correlated with in vivo performance of the dosage form and used for quality control testing to ensure consistent manufacture of the dosage form.

Diffusion of the haloform from boluses of the disclosure into the surrounding solution was tested in 1 L of a 0.02M phosphate buffer at pH 6.5 (simulating rumen pH) and at 39 °C (simulating rumen temperature) over a period of months without agitation. Samples of the buffer were taken daily and analyzed for bromoform by GC-FID. Diffusion testing has similarities to dissolution testing. Dissolution testing involves placing the dosage form in a liquid of specific pH and temperature, and with specific agitation and determining the time it takes for the active ingredient to release from the dosage form. There are standardised dissolution tests in the US and European Pharmacopoeias (USP & EP). See for example Chapter <71 1 > of the USP. However, these dissolution tests are not suitable for measuring diffusion of the dosage forms of the present disclosure, at least due to the size and extended for the length of the boluses.

Methods of administration

In another aspect, the present disclosure provides a method of administering a methane inhibitor to a ruminant animal, the method including administering to the rumen of the ruminant animal a bolus according to the present disclosure.

In another aspect, the present disclosure provides a method of reducing methane production in the rumen of a ruminant animal, the method including administering to the rumen of the ruminant animal a bolus according to the present disclosure.

In embodiments of the methods of administration of the disclosure, the bolus administers haloform to the rumen of the ruminant animal for at least about 8 weeks after administration. Optionally, the bolus administers haloform to the rumen of the ruminant animal for at least about 20 weeks after administration.

In embodiments of the methods of administration of the disclosure, following administration of the bolus the bolus sinks below the liquid surface or to the bottom of the rumen.

In embodiments of the methods of administration of the disclosure, the bolus remains in the rumen following administration for at least about 8 weeks or at least about 20 weeks.

In embodiments of the methods of administration of the disclosure, following release of the active ingredient the bolus degrades in the rumen. Optionally, the degradation is until the remnants of the bolus are of a size that can safely pass through the ruminant. In embodiments of the methods of administration of the disclosure, following administration of the bolus the methane emitted by the ruminant is reduced by about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80% by g/day. Optionally, this reduction occurs by about 5, about 10, or about 15 days following administration of the bolus. Optionally, the reduction continues for about 4 weeks, about 6 weeks, about 8 weeks, about 12 weeks, about 16 weeks or about 20 weeks. Optionally, the reduction continues at about 40 to about 90%, about 40 to about 70%, about 40 to about 50%, about 60 to about 90%, or about 70 to about 90% by g/day over the about 4 weeks, about 6 weeks, about 8 weeks, about 12 weeks, about 16 weeks or about 20 weeks.

In embodiments of the methods of administration of the disclosure, a second bolus is administered to the ruminant at about 8 to about 20 weeks, about 12 to about 20 weeks, about 8 to about 16 weeks or about 12 to about 16 weeks following the initial administration. Optionally, further bolus administration occurs regularly at these intervals. Optionally, this dosage regimen results in ongoing methane reduction of about 40 to about 90%, about 40 to about 70%, about 40 to about 50%, about 60 to about 90%, or about 70 to about 90% by g/day.

In some embodiments of the methods of the disclosure, the bolus of the disclosure comprises the methane inhibitor bromoform and reaches a maximum release rate of approximately 0.1 - approximately 0.5 g per day, and more preferably approximately 0.2 g per day.

In some embodiments, the bolus exhibits a release rate of between 0.02 g and 2 g per day into the rumen, preferably a release rate of approximately 0.1 to 0.5 g of bromoform per day. The foregoing should not be seen as limiting, and other release rates are envisaged as within the scope of the present disclosure.

In some embodiments, the bolus exhibits near zero-order release kinetics. In some embodiments, the bolus exhibits near zero-order release kinetics 2 months, 4 months and/or 6 months following administration.

Methods of production In yet another aspect, the present disclosure provides a method of making a bolus, the method including: selecting a core and a casing inserting the core into the casing, optionally closing the casing to encapsulate or substantially encapsulate the core in the casing; wherein the core includes at least one active ingredient, preferably a haloform selected from the list of chloroform, bromoform, iodoform, or combinations thereof; and at least one carrier. Optionally, the bolus further includes a densifier either dispersed in the core, in or on the casing, or separate to the core and casing (preferably within the casing).

This method may be used to prepare bolus dosage forms according to the disclosure.

In some embodiments, inserting the core into the casing occurs prior to inserting the densifier into the casing. In some embodiments, inserting the densifier into the casing occurs prior to closing the closing region of the casing.

In some embodiments, closing the closing region comprises closing two sections of the casing together. Alternatively, the closing includes closing of a cap. For example, closing the closing region comprises attaching a cap to the closing region of the casing or closing a cap already attached to the casing over the core (optionally attaching to another portion of the closing region of the casing). In some embodiments, the closing is by sealing or stitching. Optionally, the closing includes soldering and/or spin welding.

In some embodiments, the closing region includes a means to close the casing and the casing is closed using the means to close. Optionally, the means to close the casing is a cap.

In some embodiments, following closing of the closing region a closed region is formed from previously separate portions of casing that have been melted and/or soldered together. A closed region is a region that is closed during manufacture to encapsulate the core in the casing.

In some embodiments, the closing region is made of the same composition as the bulk casing. In some embodiments, the closing region is made of a different composition to the bulk casing. The skilled person will appreciate compatibility factors that will allow them to achieve closing of compositions different from one another, for instance, similarity in melting points for spin welding. In some embodiments that involve spin welding different compositions together, the melting point of the 2 compositions is within 10 °C or 5 °C of one another. Ideally, the 2 compositions should be able to form a homogeneous mixture or dispersion.

In some embodiments, the densifier is above room temperature when it is inserted in the casing. In some embodiments, at least a component of the densifier and/or densifier matrix is liquid when it is inserted in the casing.

In some embodiments, the casing is prepared by injection molding.

In some embodiments, the densifier and/or densifier matrix is in direct contact with the core. In some embodiments, the densifier and/or densifier matrix is in direct contact with the closed region. Preferably, the densifier is in direct contact with the core and the closed region. In some embodiments, the densifier and/or densifier matrix does not directly contact one or both of the core and the closed region (for instance, a further spacing component may be present preventing directing contact). In some embodiments, the core does not contact the closed region.

In some embodiments, at least a portion of the densifier may comprise a ferromagnetic material. Optionally, the one or more metal components comprise a ferromagnetic material. In some embodiments, the densifier, metal components or metal pieces consist of a ferromagnetic material, or the densifier matrix consists of a ferromagnetic material and the matrix material.

In some embodiments, the densifier or densifier matrix has a specific position in the bolus, that is, in contact with the closed region and between the closed region and the core. In some embodiments, the closed region is at a first side or end of the bolus casing and the densifier or densifier matrix is at that same side or end of the bolus within the casing. In this embodiment, the opposing side or end of the densifier is in contact with a first side or end of the core. Further, the opposing side or end of the core is in contact with the opposing side of end of the casing. Preferably, the closing region, densifier and densifier matrix are positioned at an end of the bolus. In preferred embodiments, the densifier or densifier matrix is maintained (or remains) in position during use ie the densifier or densifier matrix does not substantially move from its initial position, in particular, the densifier or densifier matrix does not sink into the core in use. In some embodiments, the densifier or densifier matrix maintains its initial position when in use such that 95% or more, 90% or more, 80% or more, 70% or more, 60% or more, or 50% or more of the volume of the densifier or densifier matrix remains in space not initially occupied by the core.

In some embodiments, the closing region includes a means to close the casing. In some embodiments, the means to close the casing is a cap. In some embodiments, the closing region includes previously separate portions of casing that are melted and/or soldered together.

Examples

The boluses and methods herein are described by the following illustrative and non-limiting examples.

Example 1 : Bolus preparation

Bolus Preparation 9A and Preparation 9B were prepared as follows.

1. Preparation of the core matrix: a) Weigh the components as listed below in Table 1. b) Put the weighed EC into a mortar (the skilled person will appreciate that other mixing apparatus can also be used, particularly on an industrial scale). c) Add bromoform in small amounts and mix with a pestle. Repeat until a uniform paste is formed. d) Add HPMC in small amount to the EC/bromoform paste and mix with a pestle. Repeat until a uniform dough is formed.

2. Preparation of the densifier matrix (although the densifier matrix was made separately for each bolus, the skilled person will appreciate that a quantity of densifier matrix suitable for numerous boluses can be prepared in a single instance and divided appropriately, particularly on an industrial scale) e) Melt the weighed wax in a beaker at 70 °C, measuring temperature using a hot plate. f) Add the weighed steel balls and allow them to equilibrate to 70 °C for 10 minutes. g) Reduce the temperature and equilibrate to 60 °C.

3. Filling the core matrix and densifier matrix in the casing and sealing

Note: Casings were prepared separately by injection moulding. The skilled person will appreciate that other techniques are also suitable. h) Weigh out 60 g of the core matrix and gently fill up the casing making sure there are little to no air gaps. i) Pour the densifier matrix prepared in step 2 on top of the core matrix. j) Allow the system to cool down and seal the bolus. Sealing can be done by soldering or spin welding, with spin welding providing preferred robustness.

Table 1. List of components and their details in Preparation 9A and Preparation 9B Example 2 - bromoform release rate

Preparation 9A and Preparation 9B boluses were assessed for bromoform release rate under the dissolution conditions described in this disclosure. Specifically, in 1 L of a 0.02 M phosphate buffer at pH 6.5 and at 39 °C without agitation. These in vitro conditions are significantly less intense than in the rumen of a ruminant animal, where there is agitation and various debris present. As shown in Figure 1 concerning Preparation 9A and Figure 2 concerning Preparation 9B, both preparations displayed pseudo-first order release kinetics over highly extended release (approximately 130 and 103 days, respectively). Preparation 9A displayed a slightly more favourable pseudo-zero release order than Preparation 9B.

Example 3 - role of ethyl cellulose in bromoform release rate

The series of Preparations of varying bromoform, ethyl cellulose and hydroxypropyl methylcellulose concentration of Table 2 were prepared according to Example 1 and assessed for bromoform release rate under the conditions described with respect to Example 2. Release rates are depicted in Figure 3. It was observed that ethyl cellulose concentration influenced the release profile of bromoform. It was also observed that an ethyl cellulose:bromoform ratio of close to 1 :2 provided the desired pseudo-zero release profile.

Table 2: Preparations of varying bromoform, ethyl cellulose and hydroxypropyl methylcellulose concentration

Example 4 - role of hydroxypropyl methylcellulose in bromoform release rate

The series of Preparations of varying bromoform, ethyl cellulose and hydroxypropyl methylcellulose concentration of Table 3 were prepared according to Example 1 and assessed for bromoform release rate under the conditions described with respect to Example 2. Release rates are depicted in Figure 4. It was observed that hydroxypropyl methylcellulose promoted the release profile of bromoform. Without wishing to be bound by theory, hydroxypropyl methylcellulose may act as a channelling agent in the Preparations of Table 3.

Table 3: Preparations of varying bromoform, ethyl cellulose and hydroxypropyl methylcellulose concentration

Example 5 - role of alternative channelling agents in bromoform release rate The series of Preparations of varying bromoform, ethyl cellulose, hydroxypropyl methylcellulose and alginate concentration of Table 4 were prepared according to Example 1 and assessed for bromoform release rate under the conditions described with respect to Example 2. Release rates are depicted in Figure 5. It was observed that inclusion of alginate promoted the release profile of bromoform. Without wishing to be bound by theory, alginate may act as a channelling agent in the Preparations of Table 4.

Table 4: Preparations of varying bromoform, ethyl cellulose, hydroxypropyl methylcellulose and alginate concentration Example 6 - role of hydrophobic fumed silica in bromoform release rate

The series of Preparations of varying bromoform, ethyl cellulose, and hydrophobic fumed silica concentration of Table 5 were prepared according to Example 1 and assessed for bromoform release rate under the conditions described with respect to Example 2. Release rates are depicted in Figure 6. It was observed that inclusion of hydrophobic fumed silica led to a decline in bromoform release rate over time.

Table 5: Preparations of varying bromoform, ethyl cellulose, and hydrophobic fumed silica concentration

Example 7 - improvements in bromoform release rate through avoiding carrier wax

A series of Preparations of varying carrier composition were prepared according to Example 1 and assessed for bromoform release rate under the conditions described with respect to Example 2. Release rates are depicted in Figure 7. It was observed that inclusion of beeswax in the carrier led to relatively uncontrolled bromoform release relative to compositions comprising ethyl cellulose.

Previous dosage forms with a core and casing for delivering a haloform were found to be inferior to the dosage forms of the present disclosure. These previous dosage forms had cores comprising active ingredient and waxes with an extended release polymeric coating. The release from these dosage forms was relatively uncontrolled and the dosage form did not achieve the length of extended release or the extended zero order release of the dosage forms of the present disclosure. Specifically, the bolus broke down earlier than desirable for the low frequency dosage that is commercially desirable. Such previous dosage forms are described in W02021221810. Replacing the wax core with a core containing cellulose polymers such that the dosage form includes extended release polymers in both the core and the casing dramatically improved the performance of the dosage form.

Example 8 - reduction in methane

Initial testing of bolus 9A in 10 ruminant bovine indicates:

- a greater than 50% reduction g/day in methane production by day 5 following administration of the bolus; - an about 90 % reduction by g/day in methane production by day 15 after administration of the bolus;

- an ongoing 70-90% reduction by g/day in methane production at 83 days (about 12 weeks).

Initial testing of bolus 9B in 10 ruminant bovine indicates:

- a greater than 50% reduction by g/day in methane production by day 5 following administration of the bolus;

- an about 70 % reduction by g/day in methane production by day 15 after administration of the bolus;

- an ongoing 70-90% reduction by g/day in methane production at 50 days (over 7 weeks).

- an ongoing 40-50% reduction by g/day in methane production at 83 days (about 12 weeks).

Both dosage forms result in long term ongoing efficacy. The performance of the 9A bolus is superior.

Example 9 - effect of temperature on release

The effect of temperature on release behaviour of the boluses was tested by preparing boluses and putting them in 1 L Schott bottles, containing 0.02M phosphate buffer (pH = 6.5), without agitation. These bottles were stored at room temperature (RT, 25 °C), 30 °C (±2 °C), and 40 °C (±2 °C) for comparison.

Preparation of the bolus

Two different bromoform loadings of boluses (1 and 2) were prepared with carrier/matrix composition as shown in the Table 6. Briefly, in each case, bromoform (purity >95%, ethanol as stabilizer: 1 -3%) was added to ethyl cellulose (EC) (Ethoxyl: 48- 49.5;Chloride- <0.05%; Apparent Viscosity- 41 -49 mPa.s) to form a sticky paste in a mortar and pestle. The skilled person will appreciate that other mixing apparatus can also be used, particularly on an industrial scale. To this mass, hydroxypropyl methyl cellulose (HPMC) (Methoxyl content- 19-24%;Hydroxypropyl content- 7-12%;Apparent Viscosity- 75000-140000 mPa.s) was added in small aliquots followed by adequate fixing to form a uniform mix. This process was repeated until all the HPMC was added, and a uniform dough/matrix was formed.

Once, the bromoform/EC/HPMC matrix was prepared, -60 g (accurately measured ±1 g) of it was loaded into the body of the housing. On top of the matrix, densifier (-100 g, accurately measured ±5 g) was added. The densifier was free stainless- steel (SS) shots (0.1 -0.5 mm diameter) in an approximately 15:1 (w/w) ratio with paraffin wax. The densifier matrix was introduced as a mix of molten paraffin wax/ stainless steel shots directly poured on top of the bromoform/EC/HPMC matrix. The housing was filled to make sure that there were little to no air gaps. As an alternative densifier option, the densifier matrix may be a premanufactured tablet of stainless steel shot/paraffin wax or any other suitably dense material. The method described for the densifier should not be considered as a limiting factor for the scope of the densifier as the purpose of the densifier is to make sure the bolus has enough density so that it sinks in the buffer and does not float. From the ruminant application perspective, the skilled person will appreciate that enough density is desired to achieve an effective bolus which can retain itself in the rumen once it has been administered to a ruminant animal. Following the addition of both carrier/matrix and densifier into the body of the housing, the cap was attached to the body by spin welding. Alternatively, a soldering gun may be used for attachment.

The housing in this case was prepared using injection moulding technique from 90% polylactic acid (PLA) (average molecular weight- -145000 g/mole; D lactic acid- 1.2%) and 10% polybutylene adipate terephthalate (PBAT) (average molecular weight- -80000 g/mol) blend. The length of each bolus housing was 73 mmm, diameter was 35 mm and the thickness was 1.2 mm. The skilled person will appreciate that other techniques in addition to injection moulding are also suitable.

Table 6. Composition of the carrier/matrix in each bolus. TBM = Tribromomethane (bromoform); EC = Ethyl Cellulose, and HPMC= Hydroxypropyl Methyl Cellulose.

DSC data on the EC suggests that it is acting amorphously.

Once the boluses were prepared, they were kept in 1 L Schott bottles, containing 0.02 M phosphate buffer (pH = 6.5) and were stored at room temperature (RT, 25 °C), 30 °C (±2 °C), and 40 °C (±2 °C). The buffer was changed every day except over weekends. Nevertheless, minimum 4 daily release data points were collected per week in all cases. Bromoform (TBM) was quantified using GC-FID (Shimadzu, Nexus GC-2030). Briefly, in each case 10 mL sample was collected using a 10 ml autopipette in 15 ml Falcon tubes. To this, 1 mL of ethyl acetate (analytical grade, Merck) was added to each Falcon tube as extraction solvent for TBM. The Falcon tubes were capped, well mixed using a Vortex, and centrifuged at 4000 rpm for 15 minutes. 0.5 mL of ethyl acetate was recovered and loaded in GC vial. 200 pl of sample was injected using an autosampler, and analysed using a ZB5HT 30 m capillary column using a temperature ramp of 30-300 °C over 20 minutes, at 5 mL/min nitrogen gas flow, in splitless mode. TBM had a retention time of -5 minutes. Peak areas were compared to calibration standards made up in ethyl acetate to determine the mass of TBM (mg) in the solution and were correlated to quantify TBM release per day in the 1 L buffer solution.

Result

Figures 9 and 10 show the release profile of the boluses (type 1 and 2; Table 6) when placed in buffer at different temperatures. A temperature dependent release was observed. In both the cases, it was observed that boluses start to release TBM earlier and in higher rate when placed at higher temperature than at lower temperature. Nevertheless, surprisingly, a bolus (Figure 9) which releases -150 mg TBM per day at 40 °C was measured to start significantly releasing from day 14 at 30 °C. However, for a bolus (Figure 10) which releases -80 mg TBM/day at 40 °C, it was observed that this bolus did not significantly release TBM for over 35 days. This suggests multiple factors at play beyond the mere role of temperature. It is well established that increase in temperature of a system leads to higher thermal energy, which can often contribute to increased diffusion. Further increased temperature may also make polymers more permeable, contributing to an increased release rate. Permeability of polymers may be affected by their composition, as well as further factors such as crystallinity.

Such changes in release behaviour can also potentially be realized through other changes such as degree of crystallinity of carrier and/or housing matrix. For instance, the inventors used amorphous EC in Example 9. The change in temperature and plasticization effect of TBM as a solvent can contribute to changes in crystallization, which can disrupt bonding interactions between TBM and EC in the matrix, contributing to increased free TBM in the matrix which can diffuse into the housing. Further, the solid state of the housing itself may be changed to high crystallinity by annealing using dry heat or use of solvent. Such changes in crystallinity may also be used to modulate the permeation or diffusion coefficients. For instance, the release of TBM from a bolus with a housing which had been crystallized (as measured by DSC) by exposure to high temperature (~80 °C) over a few hours showed lowered release of TBM over a week compared to a bolus with a housing which had not been treated with heat, and thus had more amorphous content.

Example 10 - effect of casing thickness

The effect of casing thickness on release profile was investigated using three different housing thicknesses - 0.90 mm, 1 .2 mm, and 1 .5 mm. The housing composition was the same 90% polylactic acid (PLA) and 10% polybutylene adipate terephthalate (PBAT) blend described in Example 9.

Preparation of the bolus

The boluses were assembled by loading them with matrix (bolus 2 matrix - Table 6) and the densifier matrix and then capping them as described in Example 9.

Release testing

Each bolus was placed in 1 L 0.02 M phosphate buffer as described in Example 9 and the amount of TBM released daily from the bolus was quantified. Result

The bolus with 0.9 mm housing thickness started to significantly release from day 10 (Figure 11). The bolus with 1.2 mm housing thickness started to significantly release from day 29 and the bolus with 1 .2 mm housing thickness started to significantly release from day 35. The release rate was greater for the thinner housing. This suggests an inverse relationship between housing thickness and release rate and a direct relationship between housing thickness and TBM release lag period. Here, lag period refers to the time during which the bolus does not significantly release TBM.

Example 11 - effect of bromoform and core ratios

The effect of bromoform (tribromomethane: TBM): ethyl cellulose (EC): hydroxypropyl methyl cellulose (HPMC) ratio, percentage of TBM in the core (dough), and the loading (quantity) of the matrix in the boluses on release behaviour of the boluses was tested. This was tested by preparing boluses and putting them in 1 L Schott bottles, containing 0.02 M phosphate buffer as described below. These bottles were stored at 40 °C (±2 °C) for daily release testing.

Preparation of the boluses:

Here, different boluses were prepared with varying core composition (as shown in the Table 7. Briefly, in each case, bromoform (TBM) (Assay= 96%; Sigma Aldrich or Thermo Fisher; stabilized with ethanol) was added to ethyl cellulose (EC) (Ethoxyl: 48- 49.5; Chloride- <0.05%; Apparent Viscosity- 41 -49 mPa.s; Dupont/EthoCel™) to form a sticky paste in a mortar and pestle. To this mass hydroxypropyl methyl cellulose (HPMC) (K100 M Premium; Methoxyl content- 19-24%; Hydroxypropyl content- 7-12%; Apparent Viscosity- 75000-140000 mPa.s; Dupont/ Methocel™) was added in small aliquots followed by adequate fixing to form a uniform mix. This process was repeated until all the HPMC was added, and a uniform dough/matrix was formed.

Once, the TBM/EC/HPMC matrix was prepared, generally ~60g was loaded into the body of the casing (variation in loading weight has been noted in Table 7). On top of the core, densifier (-100 g) was added. The densifier was free stainless-steel (SS) shots (0.1 -0.5 mm diameter; grade- 304; Taizhou Meanstar Hi-tech Materials Co. Ltd). As with all examples described herein, in alternative embodiments, the densifier may be a densifier matrix, such as a mix of wax (eg paraffin wax)/stainless steel (SS) shots which may be directly poured on top of the matrix or a premanufactured tablet of SS shot/wax (eg paraffin wax) or any other suitable material. The skilled person will appreciate that the purpose of the densifier and densifier matrix is to adjust the density of the bolus so that regurgitation is ameliorated/avoided and that that there are numerous preparations that are suitable to achieve this purpose. For instance, a solid block of metal may be used. In this example, following the addition of both the core and densifier into the body of the casing, the cap was attached to the body of the casing by spin welding. The cap was the same material and thickness as the bulk casing, except in the spin welded closing region, which was slightly thicker (difference less than about 0.2 mm).

The casing was prepared using injection moulding from 90% polylactic acid (PLA) (Manufacturer- NatureWorks; Brand name- Ingeo™ Biopolymer 3251 D; Specific gravity- 1 .24 Tensile strength- 62 MPa; average molecular weight- -145000 g/mole; D lactic acid- 1 .2%) and 10% polybutylene adipate terephthalate (PBAT) (Manufacturer- Zhuhai kingfa Biomaterial Co, Brand name- Kingfa KB100 HF, average molecular weight- -80000 g/mole) blend (Zhuhai kingfa Biomaterial Co., Ltd/ ECOPOND® Compostable Plastics G800 M10). The length of each bolus casing was 75 mmm, diameter was 35 mm and the thickness was 1 .2 mm. The mass of each bolus casing was 16 g.

Table 7 - compositions of boluses of Example 11

*The release tends to increase with time to achieve a plateau release (higher values compared to the listed average release over the first 30 days).

Release testing:

Once the boluses were prepared, they were kept in 1 L Schott bottles, containing 0.02 M phosphate buffer and were stored at 40 °C (±2 °C). The buffer was changed everyday except over weekends. Nevertheless, minimum 2 daily release data points were collected per week in all cases. Bromoform was quantified using GC-FID (Shimadzu, Nexus GC-2030). Briefly, in each case 8 g sample was collected using autopipette in 15 mL Falcon tubes. To this, 2 mL of heptane (Analytical GC grade, Merck) was added to each Falcon tube as extraction solvent for bromoform. The Falcon tubes were capped, well mixed using a Vortex, and centrifuged at 4000 rpm for 15 minutes. 0.5 mL of heptane was recovered and loaded in GC vial. 200 pl of sample was injected using an autosampler and analysed using a ZB5HT 30 m capillary column using a temperature ramp of 30- 300°C over 20 minutes, at 5 mL/min nitrogen gas flow, in splitless mode. Bromoform had a retention time of ~5 minutes. Peak areas were compared to calibration standards made up in heptane to determine the mass of bromoform (mg) in the solution and correlated to quantify bromoform release per day in the 1 L buffer solution.

Result:

In general, it was observed that the amount of bromoform release per day primarily depended upon the bromoforrmEC ratio, percentage of bromoform in the core and the loading of the bromoform containing core in the bolus. Examples:

A. For a given percentage of bromoform in the core (dough) and loading, a higher ratio of bromoform :EC ratio led to a higher release rate. As shown in Figure 12, when two boluses contained similar loading (~60 g) and bromoform concentration (~70%), the bolus with higher bromoforrmEC ratio released higher (F-1 > F-17). F- 1 had a bromoforrmEC ratio of 4.5:1 and F-17 had a bromoforrmEC ratio of 2.2. Similarly, the effect was observed even at other bromoform concentrations such as ~60 % (Figure 13). HPMC’s role was prominent in terms of manufacturability as it reduced stickiness of the matrix. Although breakdown of the casing is not expected over release periods that prevent utility of the bolus of the disclosure, as HPMC has gelling properties with water, in case water seeps through the casing, one skilled in the art would appreciate that inclusion of suitable levels of HPMC may potentially lead to gel formation, and thus maintenance of a substantially steady release profile. At lower bromoform concentrations (for instance, <58%), uniformity of the bromoform/EC/HPMC core was more challenging to achieve. The skilled person will appreciate that ease of uniformity of the core can be improved through numerous techniques, including inclusion of a liquid channelling/moderating agent.

B. In cases where the EC:bromoform ratios were the same in Table 7, the percentage of bromoform in the core was the primary factor in the release rate of bromoform from the boluses. As shown in Figure 14, when boluses were loaded with ~60 g of formulation F-6 (bromoform:EC ratio= 3.1 , % of TBM in matrix= 63) or formulation F-7 (bromoform:EC ratio= 3.1 , % of bromoform in matrix= 58.4), F-6 was releasing at the higher rate on account of higher bromoform % in the core.

C. The bolus of F-5 formulation (higher bromoform:EC ratio of 3.3), exhibited similar release to the bolus with F-12 formulation (lower bromoform:EC ratio of 2.6) (Figure 15). Without being limited by theory, it is hypothesised that the primary reason for such behaviour in release was the difference in loading. The bolus containing F-5 was loaded with only 54.4 g but the bolus containing F-12 formulation was loaded with ~60 g of the core. Such increase in loading also effectively increases the surface area for higher diffusion across the casing.

Example 12 - effect of water as channelling agent

The effect of water as channelling agent was tested by preparing boluses and putting them in 1 L Schott bottles, containing 0.02 M phosphate buffer as described below. These bottles were stored at 40 °C (±2 °C) for daily release testing.

Preparation of the boluses:

Here, different boluses were prepared with varying core composition (as shown in the Table 8). Briefly, in each case, bromoform (tribromoform - TBM) was added to ethyl cellulose (EC) to form a sticky paste in a mortar and pestle. To this mass, hydroxypropyl methyl cellulose (HPMC) and/or water were added in small aliquots followed by adequate fixing to form a uniform mix. This process was repeated until all the HPMC and/or water were added, and a uniform core was formed. Table 8. Details of boluses prepared to test channelling effect of water.

Once the bromoform/EC/HPMC core (with or without water) was prepared, ~60g of it was loaded into the body of the casing. On top of the matrix, densifier (-100 g) was added. Free stainless-steel (SS) shots (0.1 -0.5 mm diameter) made the densifier. Following, the addition of both core and densifier into the body of the casing, the cap was attached to the body of the casing by spin welding.

The casing was prepared and had the same dimensions as described in Example 11. Release testing:

As described in Example 11.

Result:

As shown in Figure 16, increasing the amount of water in the core increased release of bromoform from the core. During the manufacturing process, it was noted that the inclusion of water improved processibility by making the core softer. Inclusion of water in the core also increased rate of release and decreased onset of release of bromoform. Without being limited by theory, it is hypothesised that increasing the surface area of the core and/or decreasing bromoform’s affinity to the core is relevant to the rate of release and/or onset of release of bromoform. Example 13 - effect of ethanol as channelling agent

The effect of ethanol as a channelling agent was tested by preparing boluses and putting them in 1 L Schott bottles, containing 0.02 M phosphate buffer as described below. These bottles were stored at 40 °C (±2 °C) for daily release testing. Preparation of the boluses:

Here different boluses were prepared with varying core composition as shown in the Table 9. Preparation of the matrix was as described in Example 12, with ethanol replacing water as the channelling agent.

Table 9. Details of boluses prepared to test channelling effect of ethanol.

Once the bromoform/EC/HPMC matrix (with or without ethanol) was prepared, ~60g of it was loaded into the body of the casing. On top of the core, densifier (-100 g) was added. Free stainless-steel (SS) shots (0.1 -0.5 mm diameter) made the densifier. Following, the addition of both core and densifier into the body of the casing, the cap was attached to the body of the casing by spin welding.

The casing was prepared and had the same dimensions as described in Example 11.

Release testing:

As described in Example 11. Result:

As shown in Figure 17, increasing the amount of ethanol in the matrix increased release of bromoform from the matrix.

As in Example 12, during the manufacturing process, it was noted that the inclusion of ethanol improved processibility by making the matrix softer. Furthermore, inclusion of water in the core also increased rate of release and decreased onset of release of bromoform. Without being limited by theory, it is hypothesised that increasing the surface area of the core and/or decreasing bromoform’s affinity to the core is relevant to the rate of release and/or onset of release of bromoform.

Example 14 - effect of dimethyl sulfoxide as moderating agent

The effect of dimethyl sulfoxide (DMSO) as additional release moderating agent was tested by preparing boluses and putting them in 1 L Schott bottles, containing 0.02 M phosphate buffer as described below. These bottles were stored at 40 °C (±2 °C) for daily release testing.

Preparation of the boluses:

Here, different boluses were prepared with varying core composition as shown in the Table 10. Preparation of the matrix was as described in Example 12, with DMSO replacing water as the channelling agent.

Table 10. Details of /boluses prepared to test release moderating effect of DMSO.

Formulation Bromoform (% EC (% HPMC (% ^w/_w) DMSO (% ^w/_w) w/w) ^w/w)

MD-1 60 20 20

MD-2 60 20 17.3 2.7

MD-3 60 20 15 5 Once, the bromoform/EC/HPMC core (with or without DMSO) was prepared, ~60g of it was loaded into the body of the casing. On top of the core, densifier (-100 g) was added. Free stainless-steel (SS) shots (0.1 -0.5 mm diameter) made the densifier. Following, the addition of both core and densifier into the body of the casing, the cap was attached to the body by spin welding.

The casing was prepared and had the same dimensions as described in Example 11.

Release testing:

As described in Example 11.

Result:

As shown in Figure 18, it was intriguing to observe that increasing the amount of DMSO in the core tended to moderate the peak release rate. Without being limited by theory, it is hypothesised that altering bromoform’s affinity to the core is relevant to the rate of release and/or onset of release of bromoform.

Example 15 - cattle studies

An animal trial was also conducted to confirm effective methane inhibition of active doses of bromoform over 0.55 mg/kg/d and size of this inhibitory effect by using two sustained-release boluses termed Active 1 and Active 0, which were administered to cattle. This study was completed with the approval of the Ag Research Animal Ethics Committee and Ministry of Primary Industry’s Agricultural compounds and veterinary medicines (ACVM) committee.

Preparation of the boluses:

The boluses were prepared as described in Example 11. The composition of the boluses is detailed in Table 11. The bromoform used was obtained from Sigma Aldrich (Assay- = 96%; stabilized with ethanol). Other materials were the same as described in Example 11 , including the composition and size of the casing. Control boluses were also prepared without bromoform. Table 11. Details of boluses prepared for animal trial described in Example 15. zxperimental Design:

This placebo-controlled, parallel group, longitudinal trial assessed the impact of treatment with 1 of 2 TBM dosing profiles over time against a Control group on gas emissions, and rumen metabolism in pasture grazed non-lactating, non-pregnant heifers.

The parallel group design included 2 treatment types, Placebo and Active dosing, where active dosing was achieved using 1 of 2 prototype bolus treatments each with a composition and thus a different active release profile over time. This gave a total of 3 treatment groups: Control, Active 0, and Active 1 , where the 0 and 1 refer to the composition of the bolus.

Methane (CH4) emissions were measured continuously over time using GreenFeed (GF) devices (Manufacturer - C-lock Inc. ,Unit numbers 587 and 588) to determine the level and duration of a treatment effect. Metabolic impact of treatment was assessed by analysis of short-chain fatty acids (SCFAs) in rumen fluid collected at two (2) to three (3) week intervals. Briefly, in collaboration with AgResearch Ltd, Palmerston North, New Zealand and adapting a method described in Della Rosa et al, Journal of Animal Science, 2022, vol 100, 1 -11 , concentrations of SCFAs in samples (centrifuged at 21 ,000 x g for 10 min at 4 °C) were determined using a Shimadzu GC-2010 Plus and AOC 20i auto-injector (Shimadzu Corporation, Kyoto, Japan), a Phenomenex Zebron ZB- FFAP Capillary GC Column of 30 m length x 0.53 mm I.D x 1.00 pm flm thickness (Phenomenex, Torrence, CA); helium was the carrier gas (BOC, Palmerston North, NZ). The flame ionization detector was set to 240 °C, and the column temperature was 60 °C for 3.5 min, increased to 120 °C at 30°C/min, increased to 185 °C at 10 °C/min, increased to 200 °C at 15 °C/min, and then held at 200 °C for 3 min.

The study included the following phases:

1 . Training and Habituation: 35 days

This phase involved training and habituation of the animals to use the GF devices (which analyse breath of animal for composition, such as methane content), collecting baseline data for liveweight and rumen samples, and selection of 30 animals for inclusion in Phase 2.

2. Measurement: 143 days

This phase started with bolus administration on Day 0 and continued until the conclusion of the efficacious period of the boluses tested on Day 142.

All animals were grazed on ryegrass/clover pasture, with additional pelletised feed (NSmP20 - Smart Pellets, North Country Grains) as enticement through the GF unit’s available ad libitum dispenser, up to a maximum of 2.4 kg per day.

Results:

Overall, methane emissions were significantly and rapidly reduced over 10 days following bolus administration for both active treatments and remained significantly lower compared to the Control group for at least 40 days. After this period, methane emissions in the Active 1 group began to rise over 25 days, reaching levels similar to those of the Control group. In contrast, the Active 0 group maintained low emission levels for around 100 days post-treatment, after which emissions increased to match Control levels over approximately 40 days. Emissions exhibited day-to-day variability, as evidenced by the jagged nature of the mean data shown in Figure 19. Day-to-day variability is expected to result from differences in feed intake, feed quality, and GF visitation times.

To most accurately determine total methane inhibition over the period, area under the curve was calculated for each treatment group over the Measurement period (Figure 20). A mean inhibition was calculated over Day 0 to Day 142 and compared to the Control group; results showed 68% reduction in methane emissions for Active 0, and 49% for Active 1 in comparison to the Control group.

A summary of the observations has also been presented in Table 12. Variation in methane inhibition response was observed between animals for duration, level and onset of efficacy and was in line with expected biological variation.

Table 12. Tabular summary for methane emissions per treatment group over the measurement period (142 days). Example 16 - study concerning impact of ethyl cellulose viscosity Boluses were prepared to evaluate the effect of grade of ethyl cellulose (viscosity 45 grade vs viscosity 7 grade) on release profile.

Preparation of the boluses:

Here, different boluses were prepared with varying core composition (as shown in the Table 13. Briefly, in each case, tribromo methane (TBM) (Assay= ~98%, Vynova, France) was added to ethyl cellulose (EC-45) (Ethoxyl: 48-49.5;Chloride- <0.05%;Apparent Viscosity- 41 -49 mPa.s; Dupont/EthoCel™ Standard 45 Premium) or ethyl cellulose (EC- 7) ((Ethoxyl: 48-49.5;Chloride- <0.05%;Apparent Viscosity- 6-8 mPa.s; Dupont/EthoCel™ Standard 7 Premium) to form a sticky paste in a mortar and pestle. To this, mass hydroxypropyl methyl cellulose (HPMC) (K100 M Premium; Methoxyl content- 19-24%; Hydroxypropyl content- 7-12%; Apparent Viscosity- 75000-140000 mPa.s; Dupont/Methocel™) was added in small aliquots followed by adequate fixing to form a uniform mix. This process was repeated until all the HPMC was added, and a uniform dough/matrix was formed.

The boluses were assembled as detailed in Example 11.

Table 13. Details of the boluses prepared with EC-45 and EC-7.

Release testing:

As described in Example 11.

Result:

It was interesting to note that using EC7 improved the processibility of the core as it led to softer dough (lower viscosity). Nevertheless, a significant difference in release profile was not observed (Figure 21) suggesting the different grades of ethyl cellulose are substitutable in the boluses tested.

It will be understood that the disclosure disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the disclosure.

STATEMENTS OF DISCLOSURE

1. A bolus including: a core; a casing that covers at least a portion of the core; wherein the core includes (i) at least one active ingredient; (ii) at least a first cellulosic polymer that is at least about 10% w/w of the core; and (iii) optionally one or more additional excipient.

2. The bolus of statement 1 , wherein the core further comprises an integrity agent that is a second cellulosic polymer.

3. The bolus of statement 1 , wherein the core further comprises an integrity agent selected from the group consisting of hydroxypropyl methylcellulose, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), carrageenan, guar gum, xanthan gum, sodium alginate, locust bean gum, polyvinylpyrrolidone (PVP), polyvinylpyrrolidone-vinyl acetate co-polymer (PVP/VA), a polyacrylic acid and/or their co-polymer variants, combinations thereof, combinations with talc thereof, and co-polymers thereof.

4. The bolus of statement 2 or 3, wherein the integrity agent is at least about 10% w/w of the core.

5. A bolus including: a core a casing that covers at least a portion of the core; including; and at least one carrier; wherein the core includes (i) at least one active ingredient; (ii) at least a first cellulosic polymer and at least a second cellulosic polymer; and (iii) optionally additional excipient.

6. The bolus of statement 5, wherein the first cellulosic polymer is at least about 10% w/w of the core. 7. The bolus of statements 5 or 6, wherein the second cellulosic polymer is at least about 10% w/w of the core.

8. The bolus of any one of the preceding statements, wherein the bolus is formulated to remain in the rumen following administration, preferably the bolus remains in the rumen for at least 8 weeks or at least 10 weeks.

9. The bolus of any one of the preceding statements, wherein the core does not include an additional excipient.

10. The bolus of any one of the preceding statements, wherein the second cellulosic polymer and/or integrity agent is selected from the group consisting of hydroxypropyl methylcellulose, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), carrageenan, guar gum, xanthan gum, sodium alginate, locust bean gum, combinations thereof, combinations with talc thereof, and co-polymers thereof.

11 . The bolus of any one of the preceding statements, wherein the second cellulosic polymer and/or integrity agent is hydroxypropyl methylcellulose.

12. The bolus of any one of the preceding statements, wherein the first cellulosic polymer is hydrophobic.

13. The bolus of any one of the preceding statements, wherein the first cellulosic polymer is ethyl cellulose.

14. The bolus of any one of the preceding statements, wherein the core further comprises a channelling agent.

15. The bolus of any one of the preceding statements, wherein the bolus comprises a therapeutically effective amount of an active ingredient and:

• about 5% to about 15% (w/w) casing;

• about 20% to about 55% (w/w) core; and

• about 30% to about 75% (w/w) densifier. 16. The bolus of any one of the preceding statements, wherein the casing is about 0.5 to about 2.0 mm thick, preferably about 1 .0 to about 1 .8 mm thick or about 1 .2 mm thick.

17. The bolus of any one of the preceding statements, wherein the casing is about 5% to about 15% w/w of the bolus, preferably about 7% to about 12%, or about 8% w/w of the bolus.

18. The bolus of any one of the preceding statements, wherein the core is about 20 to about 55% w/w of the bolus, preferably about 30 to about 45% or about 37% w/w of the bolus.

19. The bolus of any one of the preceding statements, wherein the bolus further comprises a densifier, preferably the densifier is about 30% to about 75% w/w of the bolus, preferably about 45% to about 65%, or about 55% w/w of the bolus.

20. The bolus of any one of the preceding statements, wherein the first and/or second cellulosic polymer is about 10% to about 40%, about 15% to about 35%, or about 20% to about 30% w/w of the core.

21 . The bolus of any one of the preceding statements, wherein the integrity agent is about 10% to about 25% or about 14% to about 20% w/w of the core.

22. The bolus of any one of the preceding statements, wherein the core does not comprise hydrophobic fumed silica.

23. The bolus of any one of the preceding statements, wherein the casing is not configured to form one or more openings in at least part of the casing when exposing the casing to a temperature of between 35 °C and 45 °C, allowing the methane inhibiting agent to exit the bolus through said opening or openings; and/or wherein the casing is permeable and/or can become permeable to active ingredient before exposing the casing to a temperature of between 35 °C and 45 °C.

24. The bolus of any one of the preceding statements, wherein the core does not comprise a wax. 25. The bolus of one of the preceding statements, wherein the active ingredient is a haloform, optionally selected from the list of chloroform, bromoform, iodoform, or combinations thereof.

26. The bolus of one of the preceding statements, wherein the bolus further comprises a densifier.

27. The bolus of statement 26, wherein at least a portion of the densifier is present in a densifier matrix.

28. The bolus of any one of the preceding statements, wherein the casing includes one or more polymers selected from the list consisting of polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co-adipate (PBSA), polylactic acid (PLA), poly-D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D-lactide) (TALC PDLA), Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof.

29. The bolus of any one of the preceding statements, wherein the casing includes one or more biodegradable polymers.

30. The bolus of any one of the preceding statements, wherein the casing includes one or more polymers selected from the list consisting of polylactic acid, polybutylene adipate terephthalate, combinations thereof, and co-polymers thereof.

31. The bolus of of any one of the preceding statements, wherein the bolus is formulated for diffusion extended release.

32. The bolus of of any one of the preceding statements, wherein one or more of the following apply

- the ratio of the first cellulosic polymer to casing in the bolus is about 0.5 to about 2.5 : 1 respectively by weight, preferably about 0.8 to about 2 : 1 respectively by weight or about 0.8 to about 1 .5 : 1 respectively by weight;

- the ratio of the active ingredient to the first cellulosic polymer in the bolus is about 2.0 to about 3.5 : about 0.5 to about 2.5 respectively by weight, preferably about 2.0 to about 3.5 : about 0.8 to about 2 respectively by weight or about 2.5 to about 3 : about 0.8 to about 2 respectively by weight or about 2.5 to about 3 : about 0.8 to about 1 .5 respectively by weigh or more preferably about 2:1 by weight; and

- the ratio of the active ingredient to the first cellulosic polymer to the casing in the bolus is about 2.0 to about 3.5 : about 0.5 to about 2.5 : 1 respectively by weight, preferably about 2.0 to about 3.5 : about 0.8 to about 2 : 1 respectively by weight or about 2.5 to about 3 : about 0.8 to about 2 : 1 respectively by weight or about 2.5 to about 3 : about 0.8 to about 1 .5 : 1 respectively by weight.

33. The bolus of of any one of the preceding statements, wherein one or more of the following apply

- the ratio of the integrity agent to casing in the bolus is about 0.35 to about 1 .75 : 1 respectively by weight, preferably about 0.6 to about 1.5 : 1 respectively by weight or about 0.6 to about 1.1 : 1 respectively by weight;

- the ratio of the active ingredient to the integrity agent in the bolus is about 2.0 to about 3.5 : about 0.3 to about 1 .8 respectively by weight, preferably about 2.0 to about 3.5 : about 0.5 to about 1 .5 respectively by weight or about 2.5 to about 3 : about 0.5 to about 1 .5 respectively by weight or about 2.5 to about 3 : about 0.5 to about 1 respectively by weight

- the ratio of the active ingredient to the integrity agent to the casing in the bolus is about 1 .4 to about 2.5 : about 0.5 to about 2.5 : 1 respectively by weight, preferably about 2.0 to about 3.5 : about 0.5 to about 1.5 : 1 respectively by weight or about 2.5 to about 3 : about 0.5 to about 1.5 : 1 respectively by weight or about 2.5 to about 3 : about 0.5 to about 1 : 1 respectively by weight; and

- the ratio of the integrity agent to the first cellulosic polymer in the bolus is about 1 :1 to about 1 :2 respectively by weight, preferably about 0.8:1 to about 1 :2.5 respectively by weight or about 1 :1 or about 1 :2 respectively by weight.

34. The bolus of of any one of the preceding statements, wherein one or more of the following apply: - the ratio of the second cellulosic polymer to casing in the bolus is about 0.35 to about 1 .75 : 1 respectively by weight, preferably about 0.6 to about 1.5 : 1 respectively by weight or about 0.6 to about 1.1 : 1 respectively by weight;

- the ratio of the active ingredient to the second cellulosic polymer in the bolus is about 2.0 to about 3.5 : about 0.3 to about 1 .8 respectively by weight, preferably about 2.0 to about 3.5 : about 0.5 to about 1 .5 respectively by weight or about 2.5 to about 3 : about 0.5 to about 1 .5 respectively by weight, or about 2.5 to about 3

: about 0.5 to about 1 respectively by weight;

- the ratio of the second cellulosic polymer to the integrity agent to the casing in the bolus is about 1 .4 to about 2.5 : about 0.5 to about 2.5 : 1 respectively by weight, preferably about 2.0 to about 3.5 : about 0.5 to about 1.5 : 1 respectively by weight or about 2.5 to about 3 : about 0.5 to about 1 .5 : 1 respectively by weight or about 2.5 to about 3 : about 0.5 to about 1 : 1 respectively by weight; and

- the ratio of the second cellulosic polymer to the first cellulosic polymer in the bolus is about 1 :1 to about 1 :2 respectively by weight, preferably about 0.8:1 to about 1 :2.5 respectively by weight or about 1 :1. In some embodiments, the ratio of the second cellulosic polymer to the first cellulosic polymer in the bolus is about 1 :2 respectively by weight.

35. The bolus of of any one of the preceding statements, wherein the PLA:PBAT ratio is from about 95:5 to about 70:30 wt/wt, from about 95:5 to about 80:20 wt/wt, or from about 95:5 to about 85:15 wt/wt or about 90:10 wt/wt.

36. The bolus of of any one of the preceding statements, wherein the core and casing have a ratio of about 3 to about 6 : 1 , about 4 to about 5 : 1 or about 4.6 : 1 by weight.

37. The bolus of of any one of the preceding statements, wherein the additional excipient is a carrier.

38. The bolus of of any one of the preceding statements, wherein the bolus releases 40 to 300 mg/d of haloform when in 1 L of a 0.02M phosphate buffer at pH 6.5 and at 39 °C without agitation, preferably the release is 40 to 200 mg/day, 40 to 150 mg/day, 50 to 100 mg/day or an average (median) of about 75 mg/day.

39. The bolus of statement 38, wherein (i) the release rate is reached at about day 5 to about 15 or about day 10; and/or (ii) the release rate is maintained until day 30, 40, 50, 60, 70 or 80.

40. The bolus of any one of the preceding statements, wherein the bolus administers haloform to the rumen of the ruminant animal for at least 8 weeks after administration.

41 . The bolus of any one of the preceding statements, wherein the bolus administers haloform to the rumen of the ruminant animal for at least 20 weeks after administration.

42. A method of administering a methane inhibitor to a ruminant animal, the method including administering to the rumen of the ruminant animal the bolus of any one of the preceding statements.

43. A method of reducing methane production in the rumen of a ruminant animal, the method including administering to the rumen of the ruminant animal the bolus of any one of statements 1 to 41 .

44. The method of statement 42 or 43, wherein the active ingredient is release from the bolus by diffusion.

45. The methods of any one of statements 42 to 44, wherein the bolus administers haloform to the rumen of the ruminant animal for at least about 8 weeks after administration, preferably for at least about 20 weeks after administration.

46. The methods of any one of statements 42 to 45, wherein following administration of the bolus the bolus sinks below the liquid surface or to the bottom of the rumen.

47. The methods of any one of statements 42 to 46, wherein bolus remains in the rumen following administration for at least about 8 weeks or at least about 20 weeks.

48. The methods of any one of statements 42 to 47, wherein following release of the active ingredient the bolus degrades in the rumen, preferably the degradation is until the remnants of the bolus is of a size that can safely pass through the ruminant. 49. The methods of any one of statements 42 to 48, wherein following administration of the bolus the methane emitted by the ruminant is reduced by about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80% by g/day, preferably this reduction occurs by about 5, about 10, or about 15 days following administration of the bolus.

50. The method of statement 49, wherein the reduction continues for about 4 weeks, about 6 weeks, about 8 weeks, about 12 weeks, about 16 weeks or about 20 weeks.

51 . The methods of any one of statements 41 to 50, wherein the methane emitted by the ruminant is reduced and reduction continues at about 40 to about 90%, about 40 to about 70%, about 40 to about 50%, about 60 to about 90%, or about 70 to about 90% by g/day over about 4 weeks, about 6 weeks, about 8 weeks, about 12 weeks, about 16 weeks or about 20 weeks following administration.

52. The methods of any one of statements 42 to 51 , wherein a second bolus is administered to the ruminant at about 8 to about 20 weeks, about 12 to about 20 weeks, about 8 to about 16 weeks or about 12 to about 16 weeks following the initial administration.

53. A method of making a bolus, the method including: selecting a core and a casing inserting the core into the casing, optionally closing the casing to encapsulate or substantially encapsulates the core in the casing; wherein the core includes at least one active ingredient, preferably a haloform selected from the list of chloroform, bromoform, iodoform, or combinations thereof; and at least one carrier.

54. The method of statement 53, wherein the bolus is according to any one of claims 1 to 41 .

Claims

1. A bolus including: a core; a casing that covers at least a portion of the core; wherein the core includes (i) at least one active ingredient; (ii) at least a first cellulosic polymer that is at least about 10% w/w of the core; and (iii) optionally one or more additional excipient.

2. The bolus of claim 1 , wherein the core further comprises an integrity agent that is a second cellulosic polymer.

3. The bolus of claim 1 , wherein the core further comprises an integrity agent selected from the group consisting of hydroxypropyl methylcellulose, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), carrageenan, guar gum, xanthan gum, sodium alginate, locust bean gum, polyvinylpyrrolidone (PVP), polyvinylpyrrolidone-vinyl acetate co-polymer (PVP/VA), a polyacrylic acid and/or their co-polymer variants, combinations thereof, combinations with talc thereof, and co-polymers thereof.

4. The bolus of claim 2 or 3, wherein the integrity agent is at least about 10% w/w of the core.

5. A bolus including: a core a casing that covers at least a portion of the core; including; and at least one carrier; wherein the core includes (i) at least one active ingredient; (ii) at least a first cellulosic polymer and at least a second cellulosic polymer; and (iii) optionally additional excipient.

6. The bolus of claim 5, wherein the first cellulosic polymer is at least about 10% w/w of the core.

7. The bolus of claims 5 or 6, wherein the second cellulosic polymer is at least about 10% w/w of the core.

8. The bolus of any one of the preceding claims, wherein the bolus is formulated to remain in the rumen following administration for at least 8 weeks.

9. The bolus of any one of the preceding claims, wherein the core does not include an additional excipient.

10. The bolus of any one of the preceding claims, wherein the second cellulosic polymer and/or integrity agent is selected from the group consisting of hydroxypropyl methylcellulose, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), carrageenan, guar gum, xanthan gum, sodium alginate, locust bean gum, combinations thereof, combinations with talc thereof, and co-polymers thereof.

11 . The bolus of any one of the preceding claims, wherein the second cellulosic polymer and/or integrity agent is hydroxypropyl methylcellulose.

12. The bolus of any one of the preceding claims, wherein the first cellulosic polymer is hydrophobic.

13. The bolus of any one of the preceding claims, wherein the first cellulosic polymer is ethyl cellulose.

14. The bolus of any one of the preceding claims, wherein the core further comprises a channelling agent.

15. The bolus of any one of the preceding claims, wherein the core does not comprise hydrophobic fumed silica.

16. The bolus of any one of the preceding claims, wherein the casing is not configured to form one or more openings in at least part of the casing when exposing the casing to a temperature of between 35 °C and 45 °C, allowing the methane inhibiting agent to exit the bolus through said opening or openings; and/or wherein the casing is permeable and/or can become permeable to active ingredient before exposing the casing to a temperature of between 35 °C and 45 °C.

17. The bolus of any one of the preceding claims, wherein the core does not comprise a wax.

18. The bolus of one of the preceding claims, wherein the active ingredient is a haloform, optionally selected from the list of chloroform, bromoform, iodoform, or combinations thereof.

19. The bolus of one of the preceding claims, wherein the bolus further comprises a densifier.

20. The bolus of any one of the preceding claims, wherein the casing includes one or more polymers selected from the list consisting of polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate-co-adipate (PBSA), polylactic acid (PLA), poly- D,L-lactic acid (PDLLA), polybutylene adipate terephthalate (PBAT), styrene-acrylic copolymer (such as Joncryl®), talc-filled poly(D-lactide) (TALC PDLA), Poly(3- hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyvinyl alcohol (PVA), combinations thereof, and co-polymers thereof.

21 . The bolus of any one of the preceding claims, wherein the casing includes one or more biodegradable polymers.

22. The bolus of any one of the preceding claims, wherein the casing includes one or more polymers selected from the list consisting of polylactic acid, polybutylene adipate terephthalate, combinations thereof, and co-polymers thereof.

23. The bolus of of any one of the preceding claims, wherein the bolus is formulated for diffusion extended release.

24. A method of administering a methane inhibitor to a ruminant animal, the method including administering to the rumen of the ruminant animal the bolus of any one of the preceding claims.

25. A method of reducing methane production in the rumen of a ruminant animal, the method including administering to the rumen of the ruminant animal the bolus of any one of claims 1 to 23.

26. The method of claim 24 or 25, wherein the active ingredient is release from the bolus by diffusion.

27. The method of any one of claims 24 to 26, wherein the bolus administers haloform to the rumen of the ruminant animal for at least about 8 weeks after administration.

28. A method of making a bolus, the method including: selecting a core and a casing inserting the core into the casing, optionally closing the casing to encapsulate or substantially encapsulates the core in the casing; wherein the core includes at least one active ingredient, preferably a haloform selected from the list of chloroform, bromoform, iodoform, or combinations thereof; and at least one carrier.

29. The method of claim 28, wherein the bolus is according to any one of claims 1 to 23.