Field of the Invention

The present invention is concerned with non-aqueous oral care compositions.

Background of the Invention

Oral care compositions such as dentifrices typically contain dentally acceptable abrasive, humectant, water, and water-soluble polymer which serves as a thickener and binder for the ingredients. A variety of other ingredients such as flavours, sweeteners, preservatives and fluoride are also utilized at low levels.

However, there are many materials which are physically or chemically incompatible with the aqueous environments found in typical dentifrice formulations.

Non-aqueous formulations have been suggested as a way of improving the stability of these materials. For example, W096/03108 describes a non-aqueous dentifrice composition comprising a carboxyvinyl polymer, a humectant, a polyethylene glycol and a dentally acceptable abrasive. EP 2585031 discloses a non-aqueous oral care composition with a liquid continuous phase comprising a thickening agent, a humectant, and one or more liquid polyethylene glycols having a melting point below 25°C, in which the liquid continuous phase is structured with crystals of one or more solid polyethylene glycols having a melting point of 25°C or above.

However there remains the need for non-aqueous compositions with a good viscosity profile and flow characteristics as well as excellent storage characteristics.

It is thus an object of the present invention to provide for an oral care composition with good paste shape, ribbon height and storage stability.

Description of the Invention

A first aspect of the invention relates to a non-aqueous oral care composition comprising a non-aqueous oral care composition comprising: i) greater than 50 wt% of an organic polyol having 3 or more hydroxyl groups in the molecule; ii) a carrageenan; iii) an anionic surfactant comprising at least 50wt% of the total anionic surfactant of an alkyl sulphate based surfactant; iv) a mixture of a calcium silicate and a phosphate source which, when delivered to the teeth results in the in situ generation of hydroxyapatite on teeth.

Detailed Description of the Invention

Except in the examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use may optionally be understood as modified by the word “about’.

All amounts are by weight of the final composition, unless otherwise specified.

It should be noted that in specifying any ranges of values, any particular upper value can be associated with any particular lower value.

The disclosure of the invention as found herein is to be considered to coverall embodiments as found in the claims as being multiply dependent upon each other irrespective of the fact that claims may be found without multiple dependency or redundancy.

Where a feature is disclosed with respect to a particular aspect of the invention (for example a composition of the invention), such disclosure is also to be considered to apply to any other aspect of the invention (for example a method of the invention) mutatis mutandis.

Any ingredients mentioned in this application that are natural or naturally derived have been sourced from Europe.

The composition of the invention is non-aqueous. By “non-aqueous” it is generally meant that water is not deliberately added to the composition in any significant quantity. However, the term “nonaqueous” does not mean that small amounts of water cannot be present, for example as a consequence of its association with hygroscopic raw materials. Accordingly, for the purposes of this invention, the term “non-aqueous” generally means that water is present in an amount no greater than 5%, more preferably no greater than 3% most preferably no greater than 1 % by weight based on the total weight of the composition. Compositions according to the invention comprise carrageenan preferably at weight ratios of 1 :2 to 2:1 iota to kappa carrageenan. The carrageenan present in the composition of the invention preferably consists from 33wt% to 66wt% of the total level of iota carrageenan and 33 wt% to 66 wt% of kappa carrageenan.

The total level of carrageenan is from 0.01 to 1 wt% of the total composition, more preferably 0.05 to 0.5 wt% most preferably 0.08 to 0.25 wt%.

The composition of the invention comprise polyethylene glycol or polypropylene glycol having a melting point below 42°C, more preferably below 25°C. In a preferred embodiment of the invention the melting point is greater than -20°C and ranges from -15 to 25°C, more preferably from -5 to 8°C, most preferably from 4 to 8°C.

Preferred liquid polyethylene glycols have an average value of n in the general formula H(OCH ₂ CH ₂ ) _n OH (as described above) ranging from about 4 to 12, more preferably about 6 to 8, most preferably about 8. The average molecular weight suitably ranges from about 190 to 630, more preferably from about 285 to 420, most preferably from about 380 to 420 g/mol. Suitable commercially available materials include for example PEG 400 (ex BDH Chemicals). Mixtures of any of the above described materials may also be used.

The amount of polyethylene glycol of polyethylene glycol and/or polypropylene glycol iii (as defined above) in compositions of the invention suitably ranges from 0.1 to 10 wt% of the total composition, more preferably 0.5 to 7wt% most preferably 1 to 5 wt% on the total weight of the composition.

The preferred ratio of polyethylene glycol and/or polypropylene glycol iii) to carrageenan is from 1 :200 to 1 :4, preferably from 1 : 1 to 1 :40.

Compositions of the invention comprise organic polyols having 3 or more hydroxyl groups in the molecule (hereinafter termed “organic polyols”). Examples of such materials include glycerol, sorbitol, xylitol, mannitol, lactitol, maltitol, erythritol, and hydrogenated partially hydrolyzed polysaccharides. The most preferred organic polyol is glycerol. Mixtures of any of the above described materials may also be used.

The level of organic polyol will depend on the particular type chosen, but generally ranges from about 20 to 90% by weight based on the total weight of the composition, the amount of organic polyol suitably ranges from 35 to 85%, more preferably from 65 to 80% by total weight organic polyol based on the total weight of the composition. Ideally the composition of the invention is glycerol-based (i.e. glycerol makes up a higher portion of the composition's weight than any other compound) and contains from 55 to 80% by weight glycerol based on the total weight of the composition.

Compositions of the invention comprise an anionic surfactants, preferably an at least 50wt% of the total anionic surfactant of an alkyl sulphate based surfactant. Most preferably the anionic surfactant is sodium lauryl sulphate.

Preferably the level of anionic surfactant, more preferably sodium lauryl sulphate is from 0.1 to 5 wt%, preferably 0.5 to 3 wt% of the total composition.

Additional surfactants, such as nonionic, cationic and zwitterionic or amphoteric surfactants are preferably present at a level below 0.5 wt of the total composition, preferably less than 0.1 wt% of the composition.

The composition of the invention is used to preferably used to clean the surfaces of the oral cavity and is known as an oral care composition.

Accordingly, preferred product forms for compositions of the invention are those which are suitable for brushing and/or rinsing the surfaces of the oral cavity.

The composition of the invention is most preferably in the form of a toothpaste. Such a composition is not intentionally swallowed for purposes of systemic administration of therapeutic agents, but is applied to the oral cavity, used to treat the oral cavity and then expectorated. Typically, such a composition is used in conjunction with a cleaning implement such as a toothbrush, usually by applying it to the bristles of the toothbrush and then brushing the accessible surfaces of the oral cavity.

Preferably the dentifrice/toothpaste is in the form of an extrudable semi-solid such as a cream, paste or gel (or mixture thereof).

A composition according to the invention (such as a dentifrice/toothpaste) will generally contain further ingredients to enhance performance and/or consumer acceptability, in addition to the ingredients specified above. Compositions according to the invention, particularly toothpastes, preferably comprise particulate abrasive materials such as silicas, aluminas, calcium carbonates, dicalcium phosphates, calcium pyrophosphates, hydroxyapatites, trimetaphosphates, insoluble hexametaphosphates and so on, including agglomerated particulate abrasive materials, usually in amounts between 3 and 60% by weight of the oral care composition.

Preferably the composition, particularly a toothpaste, comprises a silica based abrasive. The preferred abrasive silicas used in the present invention is a silica with a low refractive index. It may be used as the sole abrasive silica, or in conjunction with a low level of other abrasive silicas, e.g. those according to EP 236070. The low refractive index silicas, used as abrasives in the present invention are preferably silicas with an apparent refractive index (R.l.) in the range of 1.41 - 1 .47, preferably 1 .435 - 1.445, preferably having a weight mean particle size of between 5 and 15 mm, a BET (nitrogen) surface area of between 10 and 100 m ² /g and an oil absorption of about 70 - 150 cm ³ /100 g, but abrasive silicas with a lower apparent refractive index may also be used. Typical examples of suitable low refractive index abrasive silicas (e.g. having an R.l. of between 1.435 and 1.445) are Tixosil 63 and 73 ex Rhone Poulenc; Sident 10 ex Degussa; Zeodent 113 ex Zeofinn; Zeodent 124 ex Evonik, Sorbosil AC 77 ex PQ Corporation (having an R.l. of approximately 1 .440). The amount of these silicas in the composition generally ranges from 5-60% by weight, usually 5-20% by weight.

The composition, particularly if a toothpaste preferably comprises an inorganic or a natural or synthetic thickener or gelling agent in proportions of about 0.10 to about 15% by weight depending on the material chosen. These proportions of thickeners in the dentifrice compositions of the present invention form an extrudable, shape-retaining product which can be squeezed from a tube onto a toothbrush and will not fall between the bristles of the brush but rather, will substantially maintain its shape thereon. Suitable thickeners or gelling agents useful in the practice of the present invention include inorganic thickening silicas such as amorphous silicas available from Huber Corporation under the trade designation Zeodent 165, Irish moss, iota-carrageenan, gum tragacanth, and polyvinylpyrrolidone.

Compositions according to the invention preferably comprise a polymeric deposition aid. Preferably the composition comprises acid anhydride polymers, particularly preferred are co-polymers of maleic anhydride with methyl vinylether, in which the anhydride moiety may be in a partially or fully hydrolysed or alcoholysed form. Preferred copolymers include Gantrez(R) polymers such as: Gantrez S-95: molecular weight 216,000; free acid;

Gantrez S-96: molecular weight 700,000; free acid; Gantrez S-97: molecular weight 1 ,500,000; free acid; and

Gantrez MS-955: molecular weight 1,060,000; calcium/sodium salt.

Particularly preferred co-polymers of maleic acid and methyl vinylether have a molecular weight of 1 ,000,000 or greater and an especially preferred material is Gantrez S-97.

Compositions according to the invention may comprise a tooth whitening agent. The whitening agent preferably comprises a green and/or a blue pigment. In the context of the present invention a pigment is generally understood to be a shade/material which is insoluble in the relevant medium, at the relevant temperature. This is in contrast to dyes which are soluble. In the context of this invention, the "relevant medium" is human saliva, the liquid medium in which the composition is used, at the temperature of the oral cavity during brushing of the teeth, i.e. up to 37 Degrees C. As a reasonable approximation, the relevant medium may be considered to be water and the relevant temperature to be 25 Degrees C.

Preferably the blue pigment is Pigment Blue 15, more preferably Pigment Blue 15:1, 15:2, 15:3, 15:4, 15:5 or 15:6, most preferably 15:1. A preferred pigment is blue pigment is Phthalocyanine Blue Pigment, Cl No. 74160, blue covarine.

The preferred Green pigment is Phthalocyanine Green, preferably Phthalocyanine Green CI-74260.

Preferably the total level of pigment in the composition is from 0.01 wt% to 3 wt, more preferably from 0.02 to 2 wt%.

If the composition is a toothpaste it may be a dual phase paste, with the whitening pigments present in one phase.

Compositions according to the invention may comprise water-soluble or sparingly water-soluble sources of metal salts Preferred are zinc ions such as zinc chloride, zinc acetate, zinc gluconate, zinc sulphate, zinc fluoride, zinc citrate, zinc lactate, zinc oxide, zinc monoglycerolate, zinc tartrate, zinc pyrophosphate and zinc maleate; also preferred are stannous ions such as stannous fluoride and stannous chloride.

Compositions according to the invention may comprise oral care enzyme systems such as hydrogen peroxide producing enzyme systems (e.g. the oxidoreductase enzyme glucose oxidase), amyloglucosidase, dextranase and/or mutanase, (optionally in the presence of zinc ion providing compounds and/or 8- hydroxyquinoline derivatives), lactoperoxidase, lactoferrin, lysozyme and mixtures thereof;

Compositions of the invention may comprise fluoride sources such as sodium fluoride, stannous fluoride, sodium monofluorophosphate, zinc ammonium fluoride, tin ammonium fluoride, calcium fluoride, cobalt ammonium fluoride and mixtures thereof.

The compositions of the invention includes agents for the remineralisation of teeth. The term “remineralisation” in the context of the present invention means the in situ generation of hydroxyapatite on teeth.

Theagent for the remineralisation of teeth is calcium silicate and a phosphate source which, when delivered to the teeth results in the in situ generation of hydroxyapatite on teeth.

The amount of calcium silicate in the composition of the invention typically ranges from 1 to 30%, preferably from 5 to 20% by total weight of the oral care composition.

Illustrative examples of the types of phosphate source that may be used in this context (hereinafter termed “remineralising phosphate sources”) include, for example, monosodium dihydrogen phosphate, disodium hydrogen phosphate, sodium pyrophosphate, tetrasodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, potassium dihydrogenphosphate, trisodium phosphate, tripotassium phosphate and mixtures thereof. Preferably the remineralising phosphate source is a mixture of trisodium phosphate and sodium dihydrogen phosphate.

The amount of remineralising phosphate source(s) (e.g. trisodium phosphate and sodium dihydrogen phosphate) in the composition of this invention typically ranges from 2 to 15%, preferably from 4 to 10% by total weight remineralising phosphate source based on the total weight of the oral care composition.

Mixtures of any of the above described materials may also be used.

The composition according to the invention will comprise further ingredients which are common in the art, such as: antimicrobial agents, e.g. chlorhexidine, sanguinarine extract, metronidazole, quaternary ammonium compounds, such as cetylpyridinium chloride; cetylpyridium chloride clay complex bis- guanides, such as chlorhexidine digluconate, hexetidine, octenidine, alexidine; and halogenated bisphenolic compounds, such as 2,2' methylenebis-(4-chloro-6-bromophenol); anti-inflammatory agents such as ibuprofen, flurbiprofen, aspirin, indomethacin etc.; anti-caries agents such as sodium- and stannous fluoride, aminefluorides, sodium monofluorophosphate, sodium trimeta phosphate and casein; plaque buffers such as urea, calcium lactate, calcium glycerophosphate and strontium polyacrylates; vitamins such as Vitamins A, C and E; plant extracts; plant-derivable antioxidants such as flavonoid, catechin, polyphenol, and tannin compounds and mixtures thereof; desensitising agents, e.g. potassium citrate, potassium chloride, potassium tartrate, potassium bicarbonate, potassium oxalate, potassium nitrate and strontium salts; anti-calculus agents, e.g. alkali-metal pyrophosphates, hypophosphite-containing polymers, organic phosphonates and phosphocitrates etc.; biomolecules, e.g. bacteriocins, antibodies, enzymes, etc.; flavours, e.g. peppermint and spearmint oils; proteinaceous materials such as collagen; preservatives; opacifying agents; hyaluronic acid; amino acids such as arginine; colouring agents; pH-adjusting agents; sweetening agents; pharmaceutically acceptable carriers, e.g. starch, sucrose, water or water/alcohol systems etc.;

Humectants such as glycerol, sorbitol, propylene glycol, xylitol, lactitol etc.; binders and thickeners such as sodium carboxymethyl-cellulose, hydroxyethyl cellulose (Natrosol®), xanthan gum, gum arabic etc. as well as synthetic polymers such as polyacrylates and carboxyvinyl polymers such as Carbopol®; polymeric compounds which can enhance the delivery of active ingredients such as antimicrobial agents can also be included; buffers and salts to buffer the pH and ionic strength of the oral care composition; and other optional ingredients that may be included are e.g. bleaching agents such as peroxy compounds e.g. potassium peroxydiphosphate, effervescing systems such as sodium bicarbonate/citric acid systems, colour change systems, and so on. Example of the invention will now be illustrated by the following non-limiting examples:

Examples

Table 1

*1 Sodium Methyl Cocoyl Taurate

*2 sodium lauryl sulfate *3 alkyl polyglycol ether (stearyl alcohol + 30 EO)

Viscosity was measured fresh from batch and ribbon assessments were taken at 24 hrs

The Examples above demonstrate the Example according to the invention have the most consumer acceptable ribbon height and viscosity after storage.