WO2025245012A1 - Methods for manufacturing a toothpaste composition - Google Patents

Abstract

Disclosed is a method for manufacturing a toothpaste composition, the method comprising adding at least one humectant to a mixing vessel and at least one salt to a mixing vessel; applying an agitating action to the mixing vessel to create a humectant and salt mixture; adding an acrylic polymer and at least one thickening agent to the humectant and salt mixture in the mixing vessel; applying an agitating action to the mixing vessel to create a functionalized acrylic polymer, wherein the functionalized acrylic polymer is homogenous; and optionally adding to the functionalized acrylic polymer one or more additional components of the toothpaste composition.

Description

METHODS FOR MANUFACTURING A TOOTHPASTE COMPOSITION

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority from U.S. Provisional Patent Application No. 63/650,023, filed 21 May 2024, the contents of which are hereby incorporated herein by reference in their entirety.

BACKGROUND

[0002] Certain toothpastes use hydrophilic polymers as binding agents in order to thicken the formulation and hold the product together. Binding agent polymers contribute to retention of active ingredients of the toothpaste in the oral cavity as well as controlled release of the active ingredients. Natural polymers and synthetic polymers may be used as binding agents in toothpaste. Examples of such polymers include carboxymethyl cellulose, xanthan gum, carrageenan, and poly(acrylic acid)-based polymers such as CARBOPOL®. These polymers are documented mucoadhesives, and their binding properties have been thoroughly investigated. Mucoadhesion is the adhesion between a material and a mucosal surface of an organism, i.e., increased mucoadhesion results in increased retention of at least portions of the toothpaste in contact with the mucosal surface. By retaining the toothpaste for longer in the oral cavity, the release and clearance of active ingredients can be reduced, prolonging their residency in the oral cavity.

[0003] Acrylic polymers, e.g., CARBOPOL®, may impart several desirable characteristics to toothpaste formulations including improved profiles or values for viscosity, yield value, thixotropy, and clarity. In addition, acrylic polymers may impart these characteristics at lower concentrations compared to other polymers. The combination of acrylic polymers’ ability to improve yield value while also lowering thixotropy provides for a clean, non-stringing ribbon of toothpaste from the tube during dispensing. Such acrylic polymer-containing toothpastes are pumpable, leave minimal solids residue on the tube rim, stand up well on the brush, and can be used to make clear gels.

[0004] Hydration of acrylic polymers in water is one step in the functionalization of such polymers. However, due to the hygroscopic characteristics of certain acrylic polymers, such as powdered acrylic polymers, mixing with water tends to result in undesirable lumps, i.e., mixture heterogeneity, which may preclude further mixing operations until the lumps arc eliminated and a more homogenous mixture is obtained. Overcoming this issue, i.e., obtaining a usable rheological profile and homogeneity when dispersing acrylic polymer in water, may require high-shear mixers as well as the significant energy input and time associated therewith.

[0005] A known technique to achieve a usable rheological profile and homogeneity with less intensive mixing is the pre-dispersion of acrylic polymers in a humectant such as glycol and/or glycerol. Powdered gums may also be part of this pre-dispersion formulation. Such a predispersion formulation may avoid lumps, facilitate hydration of the materials, and otherwise improve rheology by increasing the contact area and dispersion of the particles in the media. Techniques and formulations may still present issues of thick, non-flowable material.

[0006] Thus, improved methods for manufacturing toothpaste compositions that address these issues are desirable.

BRIEF SUMMARY

[0007] This summary is intended merely to introduce a simplified summary of some aspects of one or more implementations of the present disclosure. Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. This summary is not an extensive overview, nor is it intended to identify key elements of the present teachings, nor to delineate the scope of the disclosure. Rather, its purpose is merely to present one or more concepts in simplified form as a prelude to the detailed description below.

[0008] Disclosed herein is a method for manufacturing a toothpaste composition, the method comprising adding at least one humectant and at least one salt to a mixing vessel; applying an agitating action to the mixing vessel to create a humectant and salt mixture; adding an acrylic polymer and at least one thickening agent to the humectant and salt mixture in the mixing vessel; applying an agitating action to the mixing vessel to create a functionalized acrylic polymer, wherein the functionalized acrylic polymer is homogenous; and optionally adding to the functionalized acrylic polymer one or more additional components of the toothpaste composition. [0009] In another embodiment, disclosed herein is a method for manufacturing a toothpaste composition comprising: combining at least one humectant and at least one salt in a mixing vessel; mixing the at least one humectant and the at least one salt at a first mixing speed; adding to the humectant and salt mixture in the mixing vessel an acrylic polymer and at least one thickening agent; mixing the humectant and salt mixture, the acrylic polymer and the at least one thickening agent in the mixing vessel at a second mixing speed, the second mixing speed being greater than the first mixing speed, to create a functionalized acrylic polymer; and optionally adding to the functionalized acrylic polymer one or more additional components of the toothpaste composition.

[0010] In certain embodiments of the methods disclosed herein, the at least one humectant may be selected from glycol, glycerol, or glycerin, and in certain embodiments, the at least one humectant is glycerin. In certain embodiments of the disclosure, the method further comprises adding water to the mixing vessel.

[0011] In certain embodiments, the at least one thickening agent is a xanthan gum, and in certain embodiments, the xanthan gum may be present in an amount of about 0.2% to about 0.6%, such about 0.4%, by weight based on the total weight of the composition.

[0012] In certain embodiments of the disclosure, the salt may be selected from phosphate salts, and in certain embodiments, the salt may be selected from sodium fluoride, sodium monofluorophosphate, sodium fluorosilicate, tetrasodium pyrophosphate, trisodium pyrophosphate, sodium tripolyphosphate, potassium fluoride, stannous fluoride, sodium saccharin, and sodium phosphate, e.g., the at least one salt may be sodium monofluorophosphate and/or tetrasodium pyrophosphate. According to certain embodiments, the at least one salt is added in an amount ranging from about 0.5% to about 1%, preferably from about 0.6% to about 0.8%.

[0013] In certain embodiments of the disclosure, the agitating action is generated by a variable speed mixer, and in certain embodiments, the mixer agitates at a first speed while adding the at least one humectant, the acrylic polymer, the at least one salt and the at least one thickening agent, and further wherein the mixer agitates at a second speed after adding the at least one humectant, the acrylic polymer, the at least one salt and the at least one thickening agent, the second speed being higher than the first speed. According to certain embodiments, the first speed is about 500 rpm to about 700 rpm, such as about 600 rpm, and the second speed is about 1500 rpm to about 2500 rpm, such as about 2000 rpm. According to certain embodiments, the toothpaste composition has a viscosity ranging from about 10000 cps to about 30000 cps, such as from about 15000 cps to about 25000 cps, or about 18000 cps to about 21000 cps.

DETAILED DESCRIPTION

[0014] For illustrative purposes, the principles of the present disclosure are described by referencing various exemplary embodiments thereof. Although certain embodiments are specifically described herein, one of ordinary skill in the art will readily recognize that the same principles are equally applicable to and can be employed in other compositions and methods. Before explaining the disclosed embodiments in detail, it is to be understood that the disclosure is not limited in its application to the details of any particular embodiment disclosed herein. The terminology used herein is for the purpose of description and not of limitation.

[0015] As used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural references unless the context dictates otherwise. The singular form of any class of the ingredients refers not only to one chemical species within that class, but also to a mixture of those chemical species. The terms “a” (or “an”), “one or more” and “at least one” may be used interchangeably herein. The terms “comprising”, “including”, and “having” may be used interchangeably. The term “include” should be interpreted as “include, but are not limited to”. The term “including” should be interpreted as “including, but not limited to”.

[0016] As used herein, “oral care composition” refers to a composition that is delivered to the oral surfaces. The composition may be a product which, during the normal course of usage, is not, for the purpose of systemic administration of particular therapeutic agents, intentionally swallowed, but is rather retained in the oral cavity for a time sufficient to contact substantially all of the dental surfaces and/or oral tissues for the purposes of oral activity. Examples of an oral care composition include, but are not limited to, a toothpaste or a dentifrice, a mouthwash or a mouth rinse, powder (e.g., tooth powder), lozenge, mint, cream, strip or gum (e.g., chewing gum), a topical oral gel, a denture cleanser, and the like.

[0017] As used herein, the term “dentifrice” means paste, gel, or liquid formulations unless otherwise specified. In some embodiments, a dentifrice composition can be a combination of pastes, gels, or paste and gel. In some embodiments, a dentifrice composition is a toothpaste.

[0018] As used herein, the term “homogenous” refers to a consistency of a formulation, e.g., an oral care composition, wherein the consistency is generally the same throughout the entirety of a sample of the formulation. In certain embodiments, a homogenous composition indicates that the composition has generally the same or similar viscosity throughout the entirety of the composition.

[0019] As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by reference in their entireties. In the event of a conflict in a definition in the present disclosure and that of a cited reference, the present disclosure controls. [0020] Unless otherwise specified, all percentages and amounts expressed herein and elsewhere in the specification should be understood to refer to percentages by weight. The amounts given are based on the active weight of the material.

[0021] Oral care compositions having acceptable rheological properties can be obtained by formulating the oral care compositions with specific amounts of a thickening system that comprises at least one thickening agent, including for example xanthan gum and an acrylic acid polymer. It has been found that viscosity, yield stress, and pressure are kept flat over time in certain oral care compositions having, for example, an acrylic polymer-xanthan gum thickening system. Furthermore, it has been found that stand up and acceptable rheological properties in the final oral care composition product can be achieved at a low level of carbomer (e.g., about 0.4%). Thus, the use of a thickening system comprising a synthetic polyacrylic acid polymer and xanthan gum may allow for more cost-effective manufacturing of oral care compositions, such as toothpastes, which have improved rheology profile, aesthetics and mouthfeel.

Oral Care Compositions

[0022] The present subject matter is based on an oral care composition and methods of manufacturing the same. In certain embodiments, the oral care composition disclosed herein is a toothpaste or gel comprising a thickening system. In certain embodiments, the thickening system comprises xanthan gum and a synthetic polyacrylic acid polymer, i.e., acrylic polymer.

[0023] In certain embodiments, the at least one thickener in the thickening system comprises xanthan gum. Xanthan gum may be present in the oral care compositions disclosed herein in any effective amount. For example, in certain embodiments, the oral care composition can comprise an amount of xanthan gum ranging from about 0.2% to about 0.5%, by weight based on the total weight of the oral care composition. In some embodiments, xanthan gum is present in an amount of from about 0.2% to about 0.4%, from 0.3% to about 0.5%, or from about 0.35% to about 0.45%, e.g., about 0.2%, about 0.3%, about 0.4%, or about 0.5%, by weight based on the total weight of the oral care composition.

[0024] In addition to the xanthan gum, the thickening system of the oral care composition disclosed herein may further comprise at least one polymer, such as at least one synthetic polyacrylic acid polymer. In certain embodiments of the disclosure, a synthetic polyacrylic acid polymer is present in the oral care composition in an amount of from about 0.2% to about 0.5%, by weight based on a total weight of the oral care composition. In some embodiments, the synthetic polyacrylic acid polymer is present in an amount of from about 0.2% to about 0.4%, from about 0.3% to about 0.5%, or from about 0.35% to about 0.45%, c.g., about 0.2%, about 0.3%, about 0.4%, or about 0.5%, by weight based on a total weight of the oral care composition.

[0025] In some embodiments, the synthetic polyacrylic polymer disclosed herein is a carbomer. Carbomers are synthetic high-molecular-weight polyacrylic acids cross-linked with allyl sucrose or allyl pentaerythritol and contain between 56 and 68% w/w carboxylic acid groups. Non-limiting examples of carbomers can include carbomer 934, carbomer 934P, carbomer 940, carbomer 94, carbomer 1342, carbomer copolymers, carbomer homopolymers, carbomer in terpolymers, and combinations thereof. Some carbomers are available commercially, such as from B. F. Goodrich as the CARBOPOL® series. Particularly preferred CARBOPOLS® include CARBOPOL® 934, 940, 941, 956, 974P, ETD2020, and mixtures thereof. In some embodiments, the synthetic polyacrylic acid polymer is selected from CARBOPOL® 956, CARBOPOL® ETD2020, and a combination thereof. In some embodiments, the synthetic polyacrylic acid polymer is CARBOPOL® 956. In some embodiments, the synthetic polyacrylic acid polymer is CARBOPOL® ETD2020. In some embodiments, the synthetic polyacrylic acid polymer is a combination of CARBOPOL® 956 and CARBOPOL® ETD2020.

[0026] In some embodiments, the thickening system of the oral care composition disclosed herein may contain an additional thickening agent other than xanthan gum and a synthetic polyacrylic acid polymer. As used herein, the term “thickening agents” refers to agents that are used to control the viscosity of the oral care composition. Illustrative thickeners may be or include, but are not limited to, colloidal silica, fumed silica, a cross-linked polyvinylpyrrolidone (PVP) polymer, cross-linked polyvinylpyrrolidone (PVP), or the like, or mixtures or combinations thereof. In some embodiments, the thickening system comprises a cross-linked polyvinylpyrrolidone (PVP) polymer. The thickening system may also comprise POLYPLASDONE® XL I0F, which is commercially available from Ashland Inc. of Covington, Ky. Illustrative thickeners may also be or include, but are not limited to, carbomers (e.g., carboxyvinyl polymers), carrageenans (e.g., Irish moss, carrageenan, iota-carrageenan, etc.), high molecular weight polyethylene glycols (e.g., CARBOWAX®, which is commercially available from The Dow Chemical Company of Midland, Mich.), cellulosic polymers, hydroxyethylcellulose, carboxymethylcellulose, and salts thereof (e.g., CMC sodium), natural gums (e.g., karaya, gum arabic, and tragacanth), colloidal magnesium aluminum silicate, or the like, or mixtures or combinations thereof.

[0027] In some embodiments, the oral care composition does not contain any additional thickening agents other than xanthan gum and a synthetic polyacrylic acid polymer. For example, in certain embodiments, the thickening system may consist of xanthan gum and acrylic polymer.

[0028] In embodiments disclosed therein, the oral care composition comprises at least one humectant. Humectants can reduce evaporation and also contribute towards preservation by lowering water activity and can also impart desirable sweetness or flavor to compositions. Illustrative humectants may be or include, but are not limited to, glycerin, propylene glycol, polyethylene glycol, sorbitol, xylitol, glycol, or the like, or any mixture or combination thereof. In some embodiments, the at least one humectant is selected from glycerin, sorbitol, or a combination thereof. In some embodiments, the at least one humectant may be present in an amount of from 1% to 20%, for example from about 1% to about 10%, from about 2% to about 9%, about 3% to about 8%, about 4% to about 8%, about 5% to about 7%, or about 6%, by weight based on a total weight of the oral care composition. In some embodiments, the composition comprises glycerin, optionally wherein glycerin is present in an amount of from about 1% to about 10%, from about 2% to about 9%, about 3% to about 8%, about 4% to about 8%, about 5% to about 7%, or about 6%, by weight based on a total weight of the oral care composition. In some embodiments, the composition comprises sorbitol, optionally wherein sorbitol is present in an amount of from about 10% to about 40%, from about 15% to about 30%, from about 15% to about 25%, or about 20%, by weight based on a total weight of the oral care composition.

[0029] The oral care composition disclosed herein may comprise at least one salt. In certain embodiments, the at least one salt is any salt known for use in an oral care composition. In certain embodiments, the at least one salt is an alkali phosphate salt. Any phosphate salt known in the art is contemplated and may be used according to embodiments disclosed herein. In certain embodiments, the at least one phosphate salt is selected from sodium, potassium, or calcium phosphate salts. In certain embodiments, the at least one phosphate salt is selected from alkali dibasic phosphate salts and alkali pyrophosphate salts, e.g., alkali phosphate salts selected from sodium phosphate dibasic, potassium phosphate dibasic, dicalcium phosphate dihydrate, calcium pyrophosphate, tetrasodium pyrophosphate (TSPP), sodium monofluorophosphate tetrapotassium pyrophosphate, trisodium pyrophosphate, sodium tripolyphosphate (STPP), disodium hydrogenorthophosphate, monosodium phosphate, pentapotassium triphosphate, and combinations thereof. In certain embodiments, the at least one phosphate salt is selected from TSPP, sodium monofluorophosphate, and combinations thereof. The at least one phosphate salt may be added to the oral care composition in any effective amount. In certain embodiments, the at least one phosphate salt is present in an amount ranging from about 0.1% to about 5%, such as from about 0.2% to about 3%, about 0.3% to about 1%, about 0.4% to about 1%, about 0.5% to about 1%, about 0.6% to about 1%, about 0.7% to about 1%, about 0.2% to about 1%, about 0.3% to about 0.9%, about 0.4% to about 0.9%, about 0.5% to about 0.9%, about 0.6% to about 0.9%, about 0.7% to about 0.9%, about 0.3% to about 0.8%, about 0.4% to about 0.8%, about 0.5% to about 0.8%, or about 0.6% to about 0.8%, such as about 0.6%, about 0.7%, about 0.8%, or 0.76%, by weight based on the total weight of the oral care composition. In certain embodiments, the at least one phosphate salt is TSPP, and in certain embodiments, the TSPP is present in an amount of about 0.5% to about 0.7%, such as about 0.6%, by weight based on a total weight of the oral care composition. In certain embodiments, the at least one phosphate salt is sodium monofluorophosphate, and in certain embodiments, the sodium monofluorophosphate is present in an amount of about 0.7% to about 0.8%, by weight based on a total weight of the oral care composition.

[0030] In certain embodiments the at least one salt is selected from other salts known in the art for use in oral care compositions. In certain embodiments, the at least one salt is selected from sodium bicarbonate, sodium phosphate, sodium carbonate, sodium acid pyrophosphate, sodium citrate, polyphosphates (e.g., pyrophosphates), polyaminopropanesulfonic acid (AMPS), hexametaphosphate salts, zinc citrate trihydrate, polyolefin sulfonates, polyolefin phosphates, and diphosphonates. In certain embodiments, the at least one salt may be selected from sodium bicarbonate and saccharin salts.

[0031] In certain embodiments of the disclosure, water may be present in the oral care compositions disclosed herein. In certain embodiments, water employed in the preparation of commercial oral care compositions should be deionized and free of organic impurities. Water may comprise the balance of the oral care compositions disclosed herein, which may include from about 10% to about 80%, about 20% to about 60%, about 20% to 40%, about 10% to about 30%, about 20% to 30%, or about 25% to 35% water, by weight based on a total weight of the oral care compositions. This amount of water includes the free water which is added plus that amount which is introduced with other materials such as with sorbitol or any additional components.

[0032] The oral care composition may comprise any other ingredients traditionally used and known for use in oral care compositions. Such materials include but are not limited to, for example, buffering agents, anticalculus agents, abrasive polishing materials, peroxide sources, alkali metal bicarbonate salts, surfactants, titanium dioxide, coloring agents, flavor systems, sweetening agents, antimicrobial agents, herbal agents, desensitizing agents, stain reducing agents, and mixtures thereof. Such materials are well known in the art and are readily chosen by one skilled in the art based on the physical and aesthetic properties desired for the oral care composition being prepared.

[0033] In certain embodiments disclosed herein, the oral care composition may comprise calcium carbonate, such as a natural calcium carbonate, precipitated calcium carbonate or a combination thereof, in an amount of from about 25% to about 40%, such as from about 25% to about 35%, from about 30% to about 40%, from about 35% to about 40%, from about 30% to about 35%, from about 32% to about 38%, from about 33% to about 37%, from about 34% to about 36%, or about 35%, by weight based on a total weight of the oral care composition. In some embodiments, the calcium carbonate is precipitated calcium carbonate. In some embodiments, the calcium carbonate may have a particle size or D50 of less than or equal to about 10 pm, less than or equal to about 8 pm, less than or equal to about 5 pm, or less than or equal to about 3 pm. The calcium carbonate may have a particle size or D50 of greater than or equal to about 0.01 pm, greater than or equal to about 0.05 pm, greater than or equal to about 0.1 pm, greater than or equal to about 0.5 pm, or greater than or equal to about 1 pm. In some embodiments, the composition does not contain any additional abrasive other than calcium carbonate.

[0034] In some embodiments, the oral care composition comprises an additional abrasive other than calcium carbonate. As used herein, the term “abrasive” may also refer to materials commonly referred to as “polishing agents”. Any orally acceptable abrasive may be used, but preferably, type, fineness (particle size), and amount of the abrasive may be selected such that the tooth enamel is not excessively abraded in normal use of the oral care composition. The abrasives may have a particle size or D50 of less than or equal to about 10 pm, less than or equal to about 8 pm, less than or equal to about 5 pm, or less than or equal to about 3 pm. The abrasives may have a particle size or D50 of greater than or equal to about 0.01 pm, greater than or equal to about 0.05 pm, greater than or equal to about 0.1 pm, greater than or equal to about 0.5 pm, or greater than or equal to about 1 pm. Illustrative abrasives may include, but arc not limited to, metaphosphate compounds, phosphate salts (e.g., insoluble phosphate salts), such as sodium metaphosphate, potassium metaphosphate, calcium pyrophosphate, magnesium orthophosphate, trimagnesium orthophosphate, tricalcium phosphate, dicalcium phosphate dihydrate, anhydrous dicalcium phosphate, magnesium carbonate, hydrated alumina, silica, zirconium silicate, aluminum silicate including calcined aluminum silicate, polymethyl methacrylate, or the like, or mixtures and combinations thereof. In some embodiments, the additional abrasive is a silica abrasive.

[0035] The oral care composition may comprise a basic amino acid in free or salt form. The basic amino acids which can be used in the compositions include not only naturally occurring basic amino acids, such as arginine, lysine, and histidine, but also any basic amino acids having a carboxyl group and an amino group in the molecule, which are water-soluble and provide an aqueous solution with a pH of about 7 or greater. Accordingly, basic amino acids include, but are not limited to, arginine, lysine, citrulline ornithine, creatine, histidine, diaminobutanoic acid, diaminopropionic acid, salts thereof or combinations thereof. In a particular embodiment, the basic amino acids are selected from arginine, lysine, citrulline, and ornithine. The basic amino acids of the oral care composition may generally be present in the L-form or L-configuration. The basic amino acids may be provided as a salt of a di- or tri-peptide including the amino acid. In some embodiments, at least a portion of the basic amino acid present in the oral care composition is in the salt form. In some embodiments, the basic amino acid is arginine, for example, L-arginine, or a salt thereof. Arginine may be provided as free arginine or a salt thereof. For example, Arginine may be provided as arginine phosphate, arginine hydrochloride, arginine sulfate, arginine bicarbonate, or the like, and mixtures or combinations thereof. The basic amino acid may be provided as a solution or a solid. For example, the basic amino acid may be provided as an aqueous solution. In some embodiment, the amino acid includes or is provided by an arginine bicarbonate solution. For example, the amino acid may be provided by an about 40% solution of the basic amino acid, such as arginine bicarbonate or alternatively called as arginine carbamate. In some embodiments, the basic amino acid is present in an amount of from 1% to 15%, e.g., from 1% to 10%, from 1% to 5%, from 1% to 3%, from 1% to 2%, from 1.2% to 1.8%, from 1.4% to 1.6%, or about 1.5% by weight of the composition, being calculated as free base form. [0036] The oral care compositions disclosed herein may also include at least one fluoride ion source. In certain embodiments, the at least one fluoride ion source may be selected from sodium fluoride, stannous fluoride, potassium fluoride, sodium monofluorophosphate, sodium fluorosilicate, ammonium fluorosilicate, amine fluoride (e.g., N'-octadecyltrimethylendiamine- N,N,N'-tris(2-ethanol)-dihydrofluoride), ammonium fluoride, titanium fluoride, hexafluorosulfate, and combinations thereof. The fluoride ion source may be present in an amount sufficient to supply about 25 ppm to about 5,000 ppm of fluoride ions, such as at least about 500 ppm, e.g., about 500 to about 2000 ppm, about 1000 ppm to about 1600 ppm, or about 1450 ppm. [0037] In certain embodiments, the oral care composition disclosed herein may comprise at least one potassium ion source. The potassium ion source may be selected from the group consisting of potassium citrate, potassium tartrate, potassium chloride, potassium sulfate, potassium nitrate, and a combination thereof. In certain embodiments, the potassium ion source is present in an amount of from about 0.1% to about 5.5%, e.g., from about 0.1% to about 4%, or from about 0.5% to about 3%, by weight based on the total weight of the oral care composition.

[0038] The oral care composition may comprise at least one zinc ion source. The zinc ion source may be or include a zinc ion and/or one or more zinc salts. For example, the zinc salts may at least partially dissociate in an aqueous solution to produce zinc ions. Illustrative zinc salts may include, but are not limited to, zinc lactate, zinc oxide, zinc chloride, zinc phosphate, zinc citrate, zinc acetate, zinc borate, zinc butyrate, zinc carbonate, zinc formate, zinc gluconate, zinc glycerate, zinc glycolate, zinc picolinate, zinc propionate, zinc salicylate, zinc silicate, zinc stearate, zinc tartrate, zinc undecylenate, and mixtures thereof. In some embodiments, the zinc ion source is present in an amount of from about 0.01% to about 5%, e.g., from about 0.1% to about 4%, or about 1% to about 3%, by weight based on a total weight of the oral care composition.

[0039] In some embodiments, the zinc ion source is selected from zinc oxide, zinc citrate, and a combination thereof. Zinc oxide may be present in an amount of from about 0.5% to about 2%, e.g., from about 0.5% to about 1.5%, or about 1%, by weight based on a total weight of the oral composition. Zinc citrate may be present in an amount of about 0.1% to about 1%, such as from about 0.25% to about 0.75%, or about 0.5%, by weight based on a total weight of the oral care composition. In some embodiments, the composition comprises zinc oxide and zinc citrate.

[0040] The oral care composition may comprise an orally acceptable desensitizing, or tooth sensitivity protecting, agent. Suitable desensitizing agents include without limitation potassium salts such as potassium citrate, potassium tartrate, potassium chloride, potassium sulfate and potassium nitrate. Another suitable desensitizing agent is sodium nitrate. Alternatively or in addition, the composition may comprise a local or systemic analgesic such as aspirin, codeine, acetaminophen, sodium salicylate or triethanolamine salicylate. One or more desensitizing agents and/or analgesics may be present in a desensitizing and/or analgesic effective amount of typically from about 0.01% to about 5.5%, for example, from about 0.1% to about 4%, from about 0.1% to about 3% or from about 0.5% to about 3%, by weight based on a total weight of the oral care composition.

[0041] The oral care composition disclosed herein may include at least one surfactant or solubilizer. Suitable surfactants include neutral surfactants (such as polyoxyethylene hydrogenated castor oil or fatty acids of sugars), anionic surfactants (such as sodium lauryl sulfate), cationic surfactants (such as the ammonium cation surfactants) or zwitterionic surfactants. These surfactants or solubilizers may be present in amounts of typically from about 0.01% to about 5%, from about 0.01% to about 2%; or from about 1% to about 2%; or about 1.5%, by weight based on a total weight of the composition. In some embodiments, the composition may comprise an anionic surfactant. Suitable anionic surfactants include without limitation water-soluble salts of C8-20 alkyl sulfates, sulfonated monoglycerides of C8-20 fatty acids, sarcosinates, taurates and the like. Illustrative examples of these and other classes include sodium lauryl sulfate, sodium lauryl ether sulfate, ammonium lauryl sulfate, ammonium lauryl ether sulfate, sodium cocoyl monoglyceride sulfonate, sodium lauryl sarcosinate, sodium lauryl isoethionate, sodium laureth carboxylase, and sodium dodecyl benzenesulfonate. In some embodiments, the anionic surfactant, e.g., sodium lauryl sulfate (SLS), is present in an amount of from about 0.3% to about 4.5% by weight, e.g., about 1-2%, by weight based on a total of the composition. In some embodiments, the composition may comprise a betaine zwitterionic surfactant. The betaine zwitterionic surfactant may be a C8-C16 aminopropyl betaine, e.g., cocamidopropyl betaine. In some embodiments, the betaine zwitterionic surfactant, e.g., cocamidopropyl betaine, is present in an amount of from about 1% to about 1.5%, from about 1.1% to about 1.4%, from about 1.2% to about 1.3%, or about 1.25%, by weight based on a total weight of the composition. In some embodiments, the composition may comprise a non-ionic block copolymer. The non-ionic block copolymer may be a polypropylene oxide)/poly(ethylene oxide) copolymer. In some embodiments, the copolymer has a polyoxypropylene molecular mass of from 3000 to 5000 g/mol and a polyoxyethylene content of from 60 to 80 mol %. In some embodiments, the non-ionic block copolymer is a poloxamcr. In some embodiments, the non-ionic block copolymer is selected from: Poloxamer 338, Poloxamer 407, Poloxamer, 237, Poloxamer, 217, Poloxamer 124, Poloxamer 184, Poloxamer 185, and a combination of two or more thereof.

[0042] In some embodiments, the oral care compositions of the present invention may comprise polyethylene glycol (PEG) of various weight percentages of the composition as well as various ranges of average molecular weights. The PEG may have a range of average molecular weight from 100 Daltons to 1600 Daltons, preferably from 200 to 1000, from 400 to 800, from 500 to 700 Daltons, or a combination thereof. In some embodiments, the polyethylene glycol is PEG 600. In some embodiment, the PEG, e.g., PEG 600, is present in an amount of less than or equal to about 1%, such as from about 0.01% to about 1%, or from about 0.1% to about 1%, by weight based on a total weight of the composition.

[0043] The oral care compositions disclosed herein may include a preservative. Suitable preservatives include, but are not limited to, sodium benzoate, potassium sorbate, methylisothiazolinone, paraben preservatives, for example methyl p-hydroxybenzoate, propyl p- hydroxybenzoate, and mixtures thereof.

[0044] The oral care compositions disclosed herein may include a sweetener such as, for example, saccharin, for example sodium saccharin, acesulfam, neotame, cyclamate or sucralose; natural high-intensity sweeteners such as thaumatin, stevioside or glycyrrhizin; or such as sorbitol, xylitol, maltitol or mannitol. One or more of such sweeteners may be present in an amount of from about 0.005% to about 5% by weight, for example about 0.01% to about 1% or about 0.01% to about 0.5%, by weight based on a total weight of the oral care composition.

[0045] The oral care compositions disclosed herein may include a flavoring agent. Suitable flavoring agents include, but are not limited to, essential oils and various flavoring aldehydes, esters, alcohols, and similar materials, as well as sweeteners such as sodium saccharin. Examples of the essential oils include oils of spearmint, peppermint, wintergreen, sassafras, clove, sage, eucalyptus, marjoram, cinnamon, lemon, lime, grapefruit, and orange. Also useful are such chemicals as menthol, carvone, and anethole. The flavoring agent is typically incorporated in the oral care composition at a concentration of about 0.01 to about 3% by weight based on a total weight of the oral care composition. [0046] The oral care composition may include one or more pH modifying agents. For example, the oral care composition may include one or more acidifying agents and/or one or more basifying agents configured to reduce and/or increase the pH thereof, respectively. Illustrative acidifying agents and/or one or more basifying agents may be or include, but are not limited to, an alkali metal hydroxide, such as sodium hydroxide and/or potassium hydroxide, citric acid, hydrochloric acid, or the like, or combinations thereof.

[0047] The oral care composition may also include one or more buffering agents configured to control or modulate the pH within a predetermined or desired range. Illustrative buffering agents may include, but are not limited to, sodium bicarbonate, sodium phosphate, sodium carbonate, sodium acid pyrophosphate, sodium citrate, and mixtures thereof. Sodium phosphate may include monosodium phosphate (NaH PCE), disodium phosphate (Na HPO4), trisodium phosphate (NaaPO4), and mixtures thereof. In a typical embodiment, the buffering agent may be anhydrous sodium phosphate dibasic or disodium phosphate and/or sodium phosphate monobasic. In another embodiment, the buffering agent includes anhydrous sodium phosphate dibasic or disodium phosphate, and phosphoric acid (e.g., syrupy phosphoric acid; 85%-Food Grade).

[0048] The oral care composition may further include anticalculus agents. Illustrative anticalculus agents may include, but are not limited to, phosphates and polyphosphates (e.g., pyrophosphates), polyaminopropanesulfonic acid (AMPS), hexametaphosphate salts, zinc citrate trihydrate, polypeptides, polyolefin sulfonates, polyolefin phosphates, diphosphonates. In some embodiments, the anticalculus agent includes tetrasodium pyrophosphate (TSPP), sodium tripolyphosphate (STPP), or a combination thereof.

[0049] The oral care composition may include an antioxidant. Any orally acceptable antioxidant may be used, including, but not limited to, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), vitamin A, carotenoids, vitamin E, flavonoids, polyphenols, ascorbic acid, herbal antioxidants, chlorophyll, melatonin, or the like, or combinations and mixtures thereof.

[0050] The oral care composition may include one or more pigments, such as whitening pigments. In some embodiments, the whitening pigments include particles ranging in size from about 0.1 pm to about 10 pm with a refractive index greater than about 1.2. Suitable whitening agents include, without limitation, titanium dioxide particles, zinc oxide particles, aluminum oxide particles, tin oxide particles, calcium oxide particles, magnesium oxide particles, barium oxide particles, silica particles, zirconium silicate particles, mica particles, talc particles, tetracalcium phosphate particles, amorphous calcium phosphate particles, alpha-tricalcium phosphate particles, beta-tricalcium phosphate particles, hydroxyapatite particles, calcium carbonate particles, zinc phosphate particles, silicon dioxide particles, zirconium silicate particles, or the like, or mixtures and combinations thereof. The whitening pigment, such as titanium dioxide particles, may be present in an amount that is sufficient to whiten the teeth.

[0051] All ingredients for use in the compositions described herein should be orally acceptable. As used herein, “orally acceptable” may refer any ingredient that is present in a composition as described in an amount and form which does not render the composition unsafe for use in the oral cavity.

[0052] In certain exemplary embodiments disclosed herein, the oral care composition may comprise: a carbomer in an amount of from about 0.2% to about 0.5% (e.g., about 0.4%); xanthan gum in an amount of from about 0.2% to about 0.5% (e.g., about 0.4%); at least one humectant such as glycerin in an amount of from about 1% to about 10% (e.g., about 6%); and at least one phosphate salt present in an amount of from about 0.1% to 1%, by weight based on a total weight of the oral care composition. In certain embodiments, the oral care composition disclosed herein may further comprise precipitated calcium carbonate (PCC) in an amount of from about 25% to about 40% (e.g., about 35%) by weight based on a total weight of the oral care composition.

[0053] Any of the oral care compositions disclosed herein may be in the form of a toothpaste or a gel. The oral care composition disclosed herein, whether a toothpaste or a gel, may be used in methods of (i) reducing or inhibiting formation of dental caries, (ii) reducing, repairing or inhibiting pre-carious lesions of the enamel, (iii) reducing or inhibiting demineralization and promote remineralization of the teeth, (iv) reducing hypersensitivity of the teeth, (v) reducing or inhibiting gingivitis, (vi) promoting healing of sores or cuts in the oral cavity, (vii) reducing levels of acid producing bacteria, (viii) reducing or inhibiting microbial biofilm formation in the oral cavity, (ix) reducing or inhibiting plaque formation in the oral cavity, (x) promoting systemic health, or (xi) cleaning teeth and oral cavity.

[0054] In some embodiments, the oral care composition may exhibit a viscosity of 10,000- 1,000,000 cps and/or a dynamic yield stress of 60-250 Pa. Rheological properties such as viscosity and dynamic yield stress of the composition may be measured by methods known in the ail. For example, viscosity and dynamic yield stress of the composition may be measured at room temperature by Brookfield viscometer using the V74 spindle flow method, equipped with a software, c.g., Fitflow software, which calculates dynamic yield stress from measured rheological data. For example, dynamic yield stress may be calculated using the Herschel-Bulkley (HB) Model.

[0055] In certain embodiments, the oral care composition exhibits a viscosity ranging from about 10000 cps to about 1000000 cps, and in certain embodiments, the oral care composition is homogenous and substantially free of lumps. In various embodiments, the homogenous oral care composition may have a viscosity ranging from about 10000 cps to about 50000 cps, such as about 10000 cps to about 30000 cps, about 15000 cps to about 25000 cps, or about 18000 cps to about 21000 cps. In certain embodiments, the oral care composition has a viscosity of about 15000 cps, about 15500 cps, about 16000 cps, about 16500 cps, about 17000 cps, about 17500 cps, about 18000 cps, about 18500 cps, about 19000 cps, about 19500 cps, about 20000 cps, about 20500 cps, about 21000 cps, about 21500 cps, about 22000 cps, about 22500 cps, about 23000 cps, about 23500 cps, about 24000 cps, about 24500 cps, or about 25000 cps.

[0056] In another aspect, embodiments disclosed herein provide the use of a thickening system comprising xanthan gum and a synthetic polyacrylic acid polymer in the manufacture of an oral care composition, e.g., toothpaste or gel, wherein the oral care composition is as disclosed above.

Methods of Manufacturing the Oral Care Composition

[0057] Any of the oral care compositions disclosed herein require a process or method to combine the ingredients to form a paste, gel or any other dentifrice formulation profile. Typically, acrylic polymer is sourced in the form of a powder. In the event that an acrylic polymer is used in the formulation, the process typically begins with the hydration and neutralization of the acrylic polymer powder in order to achieve polymerization in accordance with manufacturer’s instructions. One type of acrylic polymer disclosed herein that may be used in accordance with embodiments is CARBOPOL®, which is a high molecular weight polymer of acrylic acid crosslinked with polyalkenyl alcohols or divinyl glycol. Powdered acrylic polymer material requires hydration and neutralization steps in order to maximize performance and activate the polymer. That is, achieving a cohesive and stable polymerization network is important to the steps following polymerization and to arriving at the final product. [0058] Hydration of the acrylic polymer in water is a key step of acrylic polymer functionalization. Due to its hygroscopic characteristics, acrylic polymer powder is known to form lumps in contact with water that require energy-intensive high-shear mixers and time to provide a desirable rheological profile. Achieving a desirable rheological profile with less aggressive mixing may be accomplished via the pre-dispersion of acrylic polymers, along with powdered gums, in a humectant, e.g., glycol and/or glycerol. Such pre-dispersion may avoid lumps, facilitate hydration of the materials and otherwise improve rheology by increasing the contact area and dispersion of the particles in the media. However, the dispersion of acrylic polymers in glycerin and, it is presumed, water according to the desired formula ratio, may result in a thick, non-flowable material.

[0059] As seen from the various oral care compositions disclosed herein, a number of ingredients are typically added to the acrylic polymer subsequent to its functionalization. It was observed that varying the timing of adding particular ingredients during the process of toothpaste formulation could have a surprising impact on the rheological properties of the acrylic polymer component and, thus, the manufacturing process. That is, earlier addition of components that are typically added at a later point into the pre-dispersion acrylic polymer, i.e., during polymer functionalization, made it possible to have a smoother dispersion and more flowable material. Such smooth dispersion and flowability improvements allowed for significant improvements in the manufacture of the toothpaste formulations, including in the efficiency and economics of such manufacture.

[0060] In an embodiment of the improved manufacturing process disclosed herein, the addition of salts to the acrylic polymer and humectant (e.g., glycerin) during pre- dispersion/polymer functionalization significantly improved dispersion and flowability or the resulting oral care composition. In one particular embodiment, the addition of tetrasodium pyrophosphate and sodium monofluorophosphate to an acrylic polymer, xanthan gum, and glycerol pre-dispersion mixture resulted in excellent flowability results that retained these excellent rheological characteristics for at least 24 hours. These excellent rheological characteristics are in contrast to the problematic rheological characteristics realized utilizing standard acrylic polymer hydration and functionalization, whether with or without glycol, glycerol, glycerin and/or powdered gums. [0061] Accordingly, disclosed herein is a method of manufacturing an oral care composition (c.g., a dentifrice such as a toothpaste), the method comprising first adding at least one humectant and at least one salt (e.g., a phosphate salt) to a mixing vessel; adding an acrylic polymer and a thickening agent to the humectant and the at least one salt; and applying an agitating action to the mixing vessel, wherein the agitating action is continued for a period of time sufficient to achieve a functionalized acrylic polymer, wherein the functionalized acrylic polymer is homogenous; and optionally adding to the functionalized acrylic polymer one or more additional components of the toothpaste composition.

[0062] In certain embodiments of the methods disclosed herein, after adding the at least one humectant (e.g., glycerin) to the mixing vessel, the glycerin is mixed, e.g., at a speed of from about 200 rpm to about 1000 rpm, such as from about 400 rpm to about 800 rpm, about 500 rpm to about 700 rpm, or about 600 rpm. In certain embodiments, after the humectant is added to the mixing vessel and optionally mixed (e.g., at 600 rpm), the at least one salt is added to the glycerin in the mixing vessel. According to certain embodiments, after addition of the at least one salt, the acrylic polymer and thickening agent(s) (e.g., xanthan gum) are added to the mixing vessel containing humectant and at least one salt. In certain embodiments, the combination of the humectant and at least one salt wherein the acrylic polymer and thickening agent have been added is them mixed at a speed of from about 1000 rpm to about 3000 rpm, such as from about 1500 rpm to about 2500 rpm, about 1750 rpm to about 2250 rpm, or about 2000 rpm.

[0063] As disclosed herein, in certain embodiments, the at least one salt added to the predispersion mixture is an ingredient that is in the ultimately desired oral care composition (a salt of a fluoride ion source, for example) and is being added at an earlier point in the formulation process than previously. Salts such as phosphate salts, pyrophosphate salts and similar may perform several possible functions in an oral care composition, as discussed hereinabove. They may act as buffering agents configured to control or modulate the pH within a predetermined or desired range. They may also act as anticalculus agents. Illustrative buffering agents may include, but are not limited to, sodium bicarbonate, sodium phosphate, sodium carbonate, sodium acid pyrophosphate, sodium citrate, and mixtures thereof. Illustrative anticalculus agents may include, but are not limited to, phosphates and polyphosphates (e.g., pyrophosphates), polyaminopropanesulfonic acid (AMPS), hexametaphosphate salts, zinc citrate trihydrate, polypeptides, polyolefin sulfonates, polyolefin phosphates, diphosphonates. Tn some embodiments, the anticalculus agent includes tetrasodium pyrophosphate (TSPP), sodium tripolyphosphatc (STPP), or a combination thereof.

[0064] The impact of salts on the dispersion of acrylic polymer in glycerin need not be limited to a single salt. Thus, a combination of salts may be added to the pre-dispersion and be expected to have positive rheological results. For example, both tetrasodium pyrophosphate and sodium monofluorophosphate may be added to the pre-dispersion. The possibility also exists of adding only a portion of the salt to the pre-dispersion and retaining the balance of the salt for addition to the formulation at a more typical point in time.

EXAMPLES

Examples 1-7

[0065] A test matrix was performed in order to compare formulations prepared in accordance with typical, e.g., according to manufacturer instructions, acrylic polymer functionalization versus the same formulations prepared in accordance with embodiments of the present disclosure. This matrix also explored the optimum amount of salt component to add to the acrylic polymer powder or at other stages during the pre-dispersion and polymer functionalization process.

[0066] Table 1 presents the initial formulation components for preparing an acrylic polymer such that a test matrix may be achieved:

Table 1

[0067] The manufacturing process for Example 1 included adding glycerin to the mixing vessel and mixing at a speed of 600 rpm, then adding the acrylic polymer and xanthan gum and increasing mixing speed to 2000 rpm. For Example 2 through Example 5, glycerin was added to the mixing vessel and mixed at a speed of 600 rpm, the salt was then added, then the acrylic polymer and xanthan gum were then added and the mixing speed was increased to 2000 rpm. For Example 6 and Example 7, water was added to the mixing vessel and mixed at a speed of 600 rpm, then the acrylic polymer and xanthan gum were added and the mixing speed was increased to 2000 rpm. Examples 6 and 7 are representative of a commonly used hydration and functionalization process for acrylic polymer, while Example 1 modifies this process by utilizing glycerin instead of water.

[0068] The result of Example 1 was considered to be poor. A very thick, non-flowable dispersion initially developed which turned into a thick, non-flowable gel after 2 minutes of mixing at the higher, 2000 rpm mixing speed. It was not possible to measure the viscosity of Example 1 as the result was close to solid.

[0069] The result of Example 2 was considered to be excellent. A homogenous, flowable gel or liquid-like product resulted within 2 minutes after beginning to mix at the higher, 2000 rpm mixing speed. The viscosity was measured at 18000 centipoise (cPS), which is a viscosity that works well in later formulation steps for toothpaste or gel. 24 hours after the mixing of the formulation, Example 2 had essentially the same characteristics as immediately after the mixing ceased. [0070] The result of Example 3 was considered to be good. A foam-like dispersion developed which tended to retain air bubbles and increase volume, i.c., become “fluffy,” when mixed at the higher, 2000 rpm mixing speed. While Example 3 resulted in a liquid, at least technically, it may pose problems if used in preparation of toothpaste or gel due to its rheology resulting from the foam-like consistency. It was not possible to measure the viscosity of Example 3 due to the foam- like consistency.

[0071] The result of Example 4 was considered to be poor. A very thick, non-flowable dispersion initially developed which turned into a thick, non-flowable gel after 4 minutes of mixing at the higher, 2000 rpm mixing speed. It was not possible to measure the viscosity of Example 4 as the result was close to solid.

[0072] The result of Example 5 was considered to be excellent. A homogenous, flowable gel or liquid- like paste product resulted within 2 minutes after beginning to mix at the higher, 2000 rpm mixing speed. The viscosity was measured at 21000 cPS, which is a viscosity that works well in later formulation steps for toothpaste or gel. 24 hours after the mixing of the formulation, Example 5 had essentially the same characteristics as immediately after the mixing ceased.

[0073] The result of Example 6 was considered to be poor. After 2 minutes of mixing at the higher, 3000 rpm mixing speed a thick mixture with lumps of material developed; after 3 minutes a large agglomeration of material developed on the mixing element and after 5 minutes a very thick mass had formed with visible lumps. It was not possible to measure the viscosity of Example 6 as the result was close to solid.

[0074] The result of Example 7 was considered to be good. After 1 minute of mixing at the higher, 2000 rpm mixing speed, a flowable gel or liquid-like mixture developed although a large number of lumps of material were present; after 5 minutes, the rheology was still very good but many lumps were still present; after 15 minutes, an unacceptable number of lumps were still present, and after 20 minutes the flowability remained excellent and the number of lumps was low enough to proceed with later formulation operations. Thus, although the ultimate result was sufficient to proceed, the amount of mixing energy and time required to achieve this result was high. Even with the positive result, there were lumps visible after 20 minutes that could present issues in future steps or the final product.

[0075] The standard process of dispersion of the acrylic polymers and xanthan gum into water is consistent with instructions-for-use for acrylic polymers. One implication from the two examples using only water, i.e., Example 6 and Example 7, and the example using only glycerin, i.c., Example 1, is that two factors may impact flowable lumps-frcc dispersion. The first factor is the amount of solvent used, and the second factor is the time of mixing. When using the same amount of solvent, 6% Glycerin (Example 1) vs. 6% water (Example 6), similar results were obtained, of a thick non-flowable dispersion. In Example 7, the water amount was increased to 34% water. Initially, this allowed the mixture to keep being mixed, not increasing its viscosity to a non-processable material. To achieve a flowable and lumps-free dispersion, it took 20 minutes of agitation. When compared to Example 2 or 5, around 10 times more time was required to achieve a similar goal, as Examples 2 and 5 were only mixed for about 2 minutes. In summary, it may be concluded from the examples that dispersion of the acrylic polymer and xanthan gum in glycerin results in a more homogenous product, taking less time and less agitation, with the addition of the mentioned salts in Example 2 or Example 5, in terms of mixing time and volume of solvent required.

[0076] Looking more specifically at the salts tested in the examples, Example 2 utilized tetrasodium pyrophosphate, and Example 5 utilized sodium monofluorophosphate. Both of these examples resulted in excellent results. Example 3 utilized a different salt (sodium bicarbonate) in a lesser amount, i.e., 0.40% vs. 0.60% and 0.76% in Example 2 and Example 5 respectively, to achieve a good result, albeit one with rheological issues. The problems with Example 3, i.e., the foaming, may be the result of the bicarbonate aspect of the salt used therein. Example 4 utilized an even lower concentration, i.e., 0.27%, of saccharin sodium and achieved a poor result.

[0077] It may be concluded from the foregoing that the addition of a salt above a threshold concentration to a pre-dispersion of an acrylic polymer and glycerin may achieve increased dispersibility of the acrylic polymer in glycerin, allowing the dispersion to retain useful rheological properties during the manufacture of oral care compositions. It is also significant that the positive results were achieved without increasing the amount of solvent in the pre-dispersion above a standard level, and the amount of mixing/agitation required to achieve a positive result was relatively low.

[0078] The present disclosure has been described with reference to exemplary embodiments. Although a limited number of embodiments have been shown and described, it will be appreciated by those skilled in the ail that changes may be made in these embodiments without departing from the principles and spirit of the preceding detailed description. It is intended that the present disclosure be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

CLAIMS WHAT IS CLAIMED IS:

1. A method for manufacturing a toothpaste composition, the method comprising: a. adding at least one humectant and at least one salt to a mixing vessel; b. applying an agitating action to the mixing vessel to create a humectant and salt mixture; c. adding an acrylic polymer and at least one thickening agent to the humectant and salt mixture in the mixing vessel; d. applying an agitating action to the mixing vessel to create a functionalized acrylic polymer, wherein the functionalized acrylic polymer is homogenous; and e. optionally adding to the functionalized acrylic polymer one or more additional components of the toothpaste composition.

2. The method of claim 1, wherein the at least one humectant is selected from glycol, glycerol, or glycerin.

3. The method of claim 1 or 2, wherein the humectant is glycerin.

4. The method of any one of claims 1-3, wherein the method further comprises adding water to the mixing vessel.

5. The method of any one of claims 1-4, wherein the at least one thickening agent is a xanthan gum.

6. The method of claim 5, wherein the xanthan gum is present in an amount of about 0.2% to about 0.6%, preferably about 0.4%, by weight based on a total weight of the toothpaste composition.

7. The method of any one of claims 1-6, wherein the at least one salt is a phosphate salt.

8. The method of any one of claims 1-6, wherein the at least one salt is selected from sodium fluoride, sodium monofluorophosphate, sodium fluoro silicate, tetrasodium pyrophosphate, trisodium pyrophosphate, sodium tripolyphosphate, potassium fluoride, stannous fluoride, sodium saccharin, and sodium phosphate.

9. The method of claim 7 or 8, wherein the at least one salt is selected from sodium monofluorophosphate and tetrasodium pyrophosphate.

10. The method of any one of claims 1-9, wherein the at least one salt is added in an amount ranging from about 0.5% to about 1%, preferably from about 0.6% to about 0.8%, more preferably about 0.6%.

11. The method of any one of claims 1-10, wherein the agitating action is generated by a variable speed mixer.

12. The method of claim 11 , wherein the mixer agitates at a first speed while adding the at least one humectant, the acrylic polymer, the at least one salt and the at least one thickening agent, and further wherein the mixer agitates at a second speed after adding the at least one humectant, the acrylic polymer, the at least one salt and the at least one thickening agent, the second speed being higher than the first speed.

13. The method of claim 12, wherein the first speed is about 500 rpm to about 700 rpm, preferably about 600 rpm, and the second speed is about 1500 rpm to about 2500 rpm, preferably about 2000 rpm.

14. The method of any one of claims 1-13, wherein the toothpaste composition has a viscosity ranging from about 10000 cps to about 30000 cps, preferably from about 15000 cps to about 25000 cps, more preferably about 18000 cps to about 21000 cps.

15. A method for manufacturing a toothpaste composition, the method comprising: a. combining at least one humectant and at least one salt in a mixing vessel; b. mixing the at least one humectant and the at least one salt at a first mixing speed; c. adding to the humectant and salt mixture in the mixing vessel an acrylic polymer and at least one thickening agent; d. mixing the humectant and salt mixture, the acrylic polymer and the at least one thickening agent in the mixing vessel at a second mixing speed, the second mixing speed being greater than the first mixing speed, to create a functionalized acrylic polymer; and e. optionally adding to the functionalized acrylic polymer one or more additional components of the toothpaste composition.

16. The method of claim 15, wherein the at least one humectant is selected glycol, glycerol, or glycerin.

17. The method of claim 15 or 16, wherein the at method further comprises adding water to the mixing vessel.

18. The method of any one of claims 15-17, wherein the first mixing speed is about 500 rpm to about 700 rpm, preferably about 600 rpm, and the second mixing speed is about 1500 rpm to about 2500 rpm, preferably about 2000 rpm.

19. The method of any one of claims 15-18, wherein the at least one thickening agent is xanthan gum.

20. The method according to claim 19, wherein the xanthan gum is present in an amount of about 0.2% to about 0.6%, preferably about 0.4%, by weight based on a total weight of the composition.

21. The method of any one of claims 15-20, wherein the at least one salt is a phosphate salt.

22. The method of any one of claims 15-20, wherein the at least one salt is selected from sodium fluoride, sodium monofluorophosphate, sodium fluorosilicate, tetrasodium pyrophosphate, trisodium pyrophosphate, sodium tripolyphosphate, potassium fluoride, stannous fluoride, sodium saccharin, or sodium phosphate.

23. The method of any one of claims 15-22, wherein the at least one salt is selected from sodium monofluorophosphate or tetrasodium pyrophosphate.

24. The method of any one of claims 15-23, wherein the at least one salt is added in an amount ranging from about 0.5% to about 1%, preferably from about 0.6% to about 0.8%, more preferably about 0.6%.

25. The method of any one of claims 15-24, wherein the toothpaste composition has a viscosity ranging from about 10000 cps to about 30000 cps, preferably from about 15000 cps to about 25000 cps, more preferably about 18000 cps to about 21000 cps.