WO2003037284A1

WO2003037284A1 - Oral hygiene composition

Info

Publication number: WO2003037284A1
Application number: PCT/EP2002/012100
Authority: WO
Inventors: Donal Hynes
Original assignee: SmithKline Beecham Ltd
Current assignee: SmithKline Beecham Ltd
Priority date: 2001-10-31
Filing date: 2002-10-29
Publication date: 2003-05-08
Anticipated expiration: 2004-04-30
Also published as: GB0126085D0

Abstract

Oral hygiene compositions comprising Coenzyme Q0 are described.

Description

ORAL HYGIENE COMPOSITION

The present invention relates to oral hygiene compositions for use in the prophylaxis and/or treatment of halitosis and/or periodontal disease. The term "periodontal disease" includes any inflammatory disease of the periodontium (tooth - surrounding tissue). Related disorders affecting the gingiva are also included herein.

Chronic adult periodontal disease is characterised by loss of gingival attachment and resorption of alveolar bone which, in extreme cases, can lead to loss of teeth. It is generally believed to be mediated by a complex interaction between the host immune system and specific oral microbial pathogens. The micro flora of the periodontal pocket are extremely complex and are believed to be mainly comprised of gram-negative obligate anaerobes and various spirochaetes. Of these Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus, Treponema denticola, Wolinella recta and Fusobacterium nucleatum are regarded as being important in the etiology of periodontal disease. Such anaerobes are also implicated in the development of halitosis.

The ability of such organisms to survive in the periodontal pocket or anaerobic pit of the tongue is dependent, in part, on the existence of a low reduction potential (Eh). The Eh is basically a measure of the oxidising or reducing power of a system. The more positive the Eh, the more oxidising the system; the more negative the Eh the more reducing the system. The oral cavity has a diverse range of reduction potentials: a clean tooth surface which has a ready supply of molecular oxygen can be as high as +200mV, the gingival crevice may have values in the region of +70mN, and the periodontal pocket where there will be little, if any molecular oxygen and one which is rich in reduced bacterial metabolites can have values as low as -300mV.

Current methods of treating chronic periodontal disease involve the mechanical removal of subgingival plaque with possible adjunctive use of antibiotics and antiseptics. An alternative approach to targeting the bacteria with antimicrobials would be to alter their environment to such an extent that they would no longer be able to survive. Raising the Eh of the periodontal pocket through the local application of redox compounds (in their oxidised state) maybe one way of achieving this. Indeed US Patent 5087451 describes the topical administration of electron acceptors to raise the reduction potential of the gingival sulcus or crevice or periodontal pocket in order to treat periodontal disease.

US Patent 3534137 describes the systemic use of certain ubiquinones in the treatment of periodontal disease. Ubiquinones disclosed include Coenzyme Q₇ and Coenzyme Q₁₀, Coenzyme Q₇ being particularly favoured.

Hanioka et al (Molec. Aspects Med. Vol. 15 (Supplement) s241-s248, 1994) describes the topical use of Coenzyme Q_IQ (CoQio) in the treatment of periodontal disease and suggests that such topical application may directly affect the bacterial environment of the periodontal pocket through a redox mechanism as postulated in US Patent 5087451.

WO 94/15595 describes topically applied medicaments comprising CoQio for use in a variety of complaints including angina pectoris, hypertension, muscular dystrophy and periodontal disease. US Patent 4654373 describes pharmaceutical compositions comprising

CoQio for topical use for the treatment of diseases of skin and mucous membranes.

It has now been discovered that Coenzyme Q₀ (CoQ₀ which is 2,3 di-methoxy- 5-methyl-l,4-benzoquinone) is surprisingly more effective than COQ_IQ as a redox agent in the prophylaxis and/or treatment of halitosis, periodontal disease and related disorders.

Accordingly in a first aspect, the present invention provides an oral hygiene composition comprising CoQo and an orally acceptable carrier or excipient.

Examples of suitable oral hygiene compositions include conventional presentations such as dentifrices, gels, mouthwashes, gargles, irrigating solutions and presentations for sucking or chewing such as gums, pastilles and lozenges.

Preferably the oral hygiene composition is capable of delivering a controlled release of CoQo directly to the diseased area, in particular to the gingival sulcus or crevice or periodontal pocket.

Therefore, in a preferred aspect, the orally acceptable carrier or excipient is topically retainable so to control the release of CoQ₀ at the site of application.

Topically retainable carriers suitable for use in the present invention include bioadhesive agents. Examples of bioadhesive agents include polymers of acrylic acid or acrylic acid derivatives, e.g. carbopol or polycarbophil, cellulose derivatives, e.g. sodium carboxymethylcellulose, hydroxypropylmethylcellulose, hydroxypropylcellulose, hydroxyethylcellulose, ethylcellulose or methylcellulose, various polymers such as polyethylene oxide, polyvinylpyrrolidone, polyvinylalcohol or polyvmylpyrrolidone/maleic anhydride copolymers, or natural materials such as chitosan, xanfhan gum, sodium alginate/alginic acid, gelatin, zein, guar gum, carrageenan, gum acacia or gum karaya, or mixtures thereof.

The bioadhesive agent can be incorporated into any of the oral hygiene presentations as hereinbefore described. Preferably such oral hygiene composition is in the form of a gel or a solid matrix which can be applied directly to the gingival sulcus or crevice or periodontal pocket. A gel formation can be applied for example by means of a syringe to the desired area. Examples of solid matrixes are described in

US Patent 5087451 and include plasters, strips or microspheres comprising a bioadhesive agent as hereinbefore described. The CoQo is applied in sufficient quantity to raise the reduction potential of the diseased anaerobic environment so to prevent the survival of pathogenic anaerobic bacteria implicated in halitosis, periodontal disease and related diseases.

Suitably the oral hygiene composition therefore comprises from 0.01 to 10% of CoQo by weight of the total composition, preferably from 0.05 to 1% by weight of the total composition.

Suitably the oral hygiene composition is applied to provide from 0.01 to 4mg of CoQo per unit dose, preferably from 0.1 to 2mg of CoQo.

Suitably the bioadhesive agent is present in the range 0.01 to 30%, preferably

0.1 to 15%, more preferably 1 to 5%, by weight of the total composition. Compositions of the present invention will contain appropriate formulating agents such as abrasives, surfactants, humectants, thickening agents, flavouring agents, sweetening agents, opacifying or colouring agents, preservatives and water, selected from those conventionally used in the oral hygiene composition art for such purposes and which are compatible with CoQo. Suitable surfactants for use in compositions according to the present invention include, for instance, anionic, nonionic, cationic and amphoteric surfactants or mixtures thereof. Suitable anionic surfactants include alkali metal (Ci2-18)^aikyl sulphates, for instance sodium lauryl sulphate, and N-acyl sarcosinates and N-acyl taurines in which the acyl moiety has from 12 to 16 carbon atoms, for instance, N-lauroyl, N-myristoyl and N-palmitoyl sarcosine alkali metal salts. Suitable nonionic surfactants include, for example, alkylpolyglucosides for instance the products marketed under the trade name 'Plantacare' by Henkel, polyethoxylated sorbitol esters, in particular polyethoxylated sorbitol monoesters, for instance, PEG(40) sorbitan di-zsostearate, and the products marketed under the trade name 'Tween' by ICI; polycondensates of ethylene oxide and propylene oxide (poloxamers), for instance the products marketed under the trade name 'Pluronic' by BASF-Wyandotte; condensates of propylene glycol; polyethoxylated hydrogenated castor oil, for instance, cremophors; and sorbitan fatty esters.

Suitable amphoteric surfactants include, for example, long chain imidazoline derivatives such as the product marketed under the trade name 'Miranol C2M' by Miranol; long chain alkyl betames, such as the product marketed under the tradename 'Empigen BB' by Albright + Wilson, and long chain alkyl amidoalkyl betaines, such as cocamidopropylbetaine, and mixtures thereof.

Suitable cationic surfactants include the D,L-2-pyrrolidone-5-carboxylic acid salt of ethyl-N-cocoyl-L-arginate, marketed under the trade name CAE by Ajinomoto Co. Inc., and cocamidopropyl PG dimonium chloride phosphate and lauramidopropyl PG dimonium chloride phosphate, available under the trade names Monaquat PTC and Monaquat PTL, respectively, from Mona Corporation.

Advantageously, the surfactant is present in the range 0.005 to 20%, preferably 0.1 to 10%, more preferably 0.1 to 5% by weight of the total composition. Suitable thickening agents for gel or dentifrice formulations include, for instance, nonionic thickening agents such as, for example, (C[-6)alkylcellulose ethers, for instance methylcellulose; hydroxy(Cι^6)aιkylceιlulose ethers, for instance hydroxyethylcellulose and hydroxypropylcellulose; (C2"6)^alkylene oxide modified (Cι-6)alkylcellulose ethers, for instance hydroxypropyl methylcellulose; and mixtures thereof. Other thickening agents such as natural and synthetic gums or gum like material such as Irish Moss, xanfhan gum, gum tragacanth, sodium carboxymethylcellulose, polyvinyl pyrrolidone, starch and thickening silicas may also be used. Preferably the thickening agent is xanthan gum. It will be appreciated that certain thickening agents may also function as the bioadhesive agent.

Advantageously the thickening agent is present in the range 0.01 to 30%, preferably 0.1 to 15%, more preferably 1 to 5%, by weight of the total composition. Suitable humectants for use in compositions of the invention include for instance, glycerine, xylitol, sorbitol, propylene glycol or polyethylene glycol, or mixtures thereof; which humectant may be present in the range from 5 to 30%, preferably 5 to 20%, more preferably 5 to 15% by weight of the total composition.

Suitable abrasives for use in dentifrice compositions of the present invention include calcium carbonate, calcium phosphates, calcium pyrophosphate, insoluble sodium metaphosphate, sodium aluminosilicate, alumina, hydrated alumina, zinc orthophosphate, plastic particles, and silica, of which silica is the preferred abrasive.

Suitable silicas include natural amorphous silicas, such as, for instance, diatomaceous earth, and synthetic amorphous silicas, such as precipitated silicas and silica gels, including silica xerogels. Suitable silica xerogels are described in US

3,538,230. Suitable grades of precipitated silicas have BET surface areas in the range 20 to 300, preferably 20 to 100 m^/g and median agglomerate sizes in the range 2 to 50, preferably 5 to 30m.

Suitable precipitated silicas and silica xerogels are those marketed under the trade names Sident and Syloblanc, by Degussa and W R Grace Corporation Davison Chemical Division, respectively.

Advantageously, the silica is a "low anion" silica. As used herein, the term "low-anion" silicas refers to those in which anionic impurities such as sodium sulphate and sodium silicate which normally arise during the course of the manufacturing process are kept to a minimum, through careful control of the manufacturing process. "Low anion" silicas suitably have less than 1%, preferably less than 0.5% advantageously less than 0.25% by weight of anionic impurities.

Suitable such "low anion" silicas are described in EP 0 368 130 (Procter & Gamble), EP 0 315 503 and EP 0 396 459 (Rhone-Poulenc) and WO 90/05113 (J.M. Huber Corp). Alternatively, grades of commercially available silica with ionic impurities may be rendered suitable by washing thereof with deionised water. Conductivity measurements on the water after washing may be used to monitor the efficacy of such washing. Suitably the conductivity of the water after washing is reduced to less than 200μSiemens/cm. Suitable "low anion" silicas include the grade RP93 available from Rhone-Poulenc.

Suitably, dentifrice compositions will have from 5 to 80%, preferably from 10 to 60% by weight of the abrasive.

Compositions according to the present invention will have a pH which is orally acceptable, typically ranging from about pH 4 to 10, e.g. 5.5 to 8.

Compositions according to the present invention may be prepared by admixing the ingredients in the appropriate relative amounts in any order that is convenient and thereafter and if necessary adjusting the pH to give the final desired value.

The following examples illustrate the invention. Example 1 Effect of COQ_NJ and CoQo on the Reduction Potential and Survival of Broth cultures of P.gingivalis CoQo and CoQio were prepared as 0.3 M stock solutions using DMSO

(dimethylsulphoxide) as solvent. (CoQio is only sparingly soluble in DMSO). fn an anaerobic cabinet at 37°C, 2ml of a culture of P.gingivalis, grown anaerobically for 48 hours in Wilkins-Chalgrin (WC) Broth supplemented with 5μg/ml haemin and 0.5μg/ml menadione, was added to 2ml of pre-reduced (48 hours) WC Broth supplemented with 5μg/ml haemin and 0.5μg/ml menadione.

In duplicate, 40 μl of each test compound stock solution was added to the above prepared culture to give a final concentration of 3.0mM and then incubated anaerobically at 37°C for up to 48 hours. Either deionised water or 1% DMSO (final concentration) were used as controls. Samples were taken for viable counting and reduction potential measurements were determined at set time points.

Viable counts was determined by performing serial dilutions of culture down to 10^"8 by transferring lOOμl volumes sequentially into 4 x 9ml volumes of PBS. Miles and Misra counts were carried out on blood agar and incubated for 48 hours.

Reduction potential values were taken 5 minutes after the electrode was placed into the incubation solution to allow for reading to steady. The pH reading was converted to mV using the following equation: mN= 2.303*8.3144*D*7-A*1000/96485 A= pH reading on display and

D = absolute temperature measured in K (i.e. measured temp + 273) The following results were obtained:

Agent Reduction Potential V CFU/ml

(Time (h)) 0 3 24 0 3 24

CoQo -20 -55 -229 <5000 <5000 <5000

CoQio -200 -302 -347 2.7 x lO⁹ 2.3 x 10⁹ 3.2 x lO⁹

The Eh of the P.gingivalis culture immediately following the addition of either deionised water or DMSO was raised to -202 mN and -208 mN respectively. This initial rise in Eh was not maintained and dropped to -365 mV and -355 mN respectively over 24 hours. Bacterial cell viability remained fairly constant, viable counts increasing from 2.5 x 10⁹ cfu/ml to 3.3 x 10⁹ cfu/ml over 24 hours for deiomsed water and increasing from 2.2 x 10⁹ cfu/ml to 3.1 x 10⁹ cfu/ml over 24 hours for the DMSO control.

The addition of CoQo to the P.gingivalis culture raised the Eh to -20mN. This dropped to -55 mN after 3 hours of anaerobic incubation and then to -229 mV after 24 hours. Under these conditions of raised Eh bacteria did not survive and viable counts remained at undetectable levels (<5000 cfu/ml).

The Eh of the P.gingivalis culture following the addition of CoQio, was -200mN. This dropped back to control values after 24 hours. Bacterial viability was unaffected under these conditions. These results indicate the CoQo causes the immediate death of P.gingivalis implicated in various oral health diseases such as halitosis and periodontal disease and therefore can be expected to be of use in the topical treatment of such diseases. Example 2 MIC Determination of CoQo n the absence and presence of Dithiothreitol 100 μl of Wilkins-Chalgrin (WC) Broth was added to the wells of a 96 well microtitre plate either alone or in the presence of dithiothreitiol [(DTT) to give a final concentration of 2 mg/ml]. P. gingivalis W50 was grown over 48 hours in WC Broth supplemented with 5 μg/ml of haemin and 0.5 μg/ml of menadione, 20 μl of this culture was added to each well.

CoQo was prepared as a stock solution (2% w/v in DMSO) and titred out in doubling dilutions across the plate. Plates were incubated anaerobically for 48 hours.

The turbidity of each well was measured in comparison with controls (no active/bacteria, no active/no bacteria, active/no bacteria). Interpretation of growth /no growth can then be determined over a wide range of concentrations (10,000ppm - 19.5ppm). Dithiothreitol (DTT), a strong reducing agent without any direct antimicrobial activity itself, is used in this experiment to counteract the oxidising ability of the CoQo.

It was observed that CoQo inhibits the growth of P.gingivalis in the absence of DTT. However this inhibition was reversed in the presence of DTT suggesting that CoQo produces its antibacterial effect through a redox specific mechanism of action.

Example 3

Anti-malodour properties of Coenzyme Q₀

The effect of a 20mM solution of Coenzyme Qo on VSC production by microcosm tongue biofilms has been investigated. When 10-day old biofilms, grown in a Constant Depth Film Fermentor, were immersed in the solution for 1 minute, this was associated with a significant reduction in NSCs produced by the biofilms (as compared to water treated controls; Fig.l). This occurred without a significant reduction in bacterial viability within the biofilm (Fig.2), suggesting that Coenzyme Qo can moderate NSC production by a means other than an antibacterial mode of action. Fig. l

100

Fig. 2

Control CoQO 20m

This finding was investigated further by bubbling 2 selected NSCs - hydrogen sulphide and methyl mercaptan - through a 20mM solution of CoQo. Both of these were found to react with CoQo, giving rise to reaction products which did not smell. Example 4

A gel formulation is made up to contain:

%w/w

CoQo 0.1

Hydroxypropylcellulose 2.5

Ethanol 4

Disodium phosphate 0.001

Monosodium phosphate 0.00156

Water to 100

Final pH 7.0

Example 5

A mouthwash formulation is made up to contain:

%w/w

CoQo 0.1

Ethanol 15

Disodium phosphate 0.001

Monosodium phosphate 0.00156

Poloxamer surfactant 0.5

Flavours 0.1

Water to 100%

Final pH 7.2

Claims

1. An oral hygiene composition comprising CoQo and an orally acceptable carrier or excipient.

2. A composition according to claim 1 wherein the orally acceptable carrier or excipient is topically retainable.

3. A composition according to claim 2 wherein the topically retainable carrier or excipient comprises a bioadhesive agent.

4. A composition according to any one of claims 1 to 3 in the form of a gel or solid matrix.

5. A composition according to any one of claims 1 to 4 comprising 0.01 to 10% of CoQo by weight of the total composition.

6. Use of CoQo in the manufacture of an oral hygiene composition as defined in any one of claims 1 to 5 for the prophylaxis and/or treatment of halitosis, periodontal disease and related disorders.

7. A method for the prophylaxis and/or treatment of halitosis, periodontal disease and related disorders which comprises topically applying to a patient in need thereof sufficient amount of a composition as defined in any one of claims 1 to 5.