Technical Field of the Invention

The present invention relates to oral care compositions such as toothpastes, powders, gums, serums, films, mouthwashes and the like. In particular the present invention relates to an oral care compositions, particularly toothpastes and serums that are effective in mitigating the negative effects of wearing a retainer on the enamel.

Background of the Invention

Tooth aligners, in particular clear aligners have become increasingly popular with consumers over recent years. However, aligner treatment may put consumers at higher risk of enamel demineralisation as the aligner inhibits natural remineralisation by saliva creating a minienvironment around the teeth conducive to demineralization.

There remains the need to provide improved methods of using oral care compositions to protect tooth enamel from the negative effects of wearing a retainer.

Description of the Invention

The present invention relates to an oral care composition comprising: a) calcium silicate and; b) sodium phosphate salt. for use in a method to mitigate erosion of tooth enamel by use of a retainer/aligner

In a second aspect use of a composition as described above for mitigation and or reversion of erosion of tooth enamel by use of a retainer.

In a third aspect the invention relates to kit comprising a retainer for straightening the teeth and an oral care composition comprising: a) calcium silicate and b) sodium phosphate salt.

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 composition, unless otherwise specified.

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

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 are toothpastes, films, powders, gums, serums and mouthwashes. Serums and toothpastes are particularly preferred.

The composition of the invention is most preferably in the form of a dentifrice. The term "dentifrice" denotes an oral composition which is used to clean the surfaces of the oral cavity. 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). Toothpastes are particularly preferred.

Application of the composition can be by the brushing the teeth with the product, preferably without rinsing or by applying the product with an applicator. The composition of the invention may be applied to the teeth prior to placement of the aligner or after removal of the aligner

Compositions according to the invention preferably comprise mono calcium phosphate. Preferably the monocalcium phosphate is present at levels from 0.1 to 10 wt% of the total composition, more preferably 1 to 6 wt%. The compositions of the invention comprise from 20 to 90 wt% of the total composition of one or more organic polyols having 3 or more hydroxyl groups in the molecule. Preferably the organic polyol is glycerol.

The compositions of the invention include 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.

Compositions according to the invention comprise a suitable agent for the remineralisation of teeth this a mixture of a calcium silicate and a sodium phosphate salt which, when delivered to the teeth results in the in situ generation of hydroxyapatite on teeth.

The amount of remineralising calcium source(s) (e.g. calcium silicate) in the composition of the invention typically ranges from 1 to 30%, preferably from 5 to 20% by total weight remineralising calcium source based on the total weight of the oral care composition.

Illustrative examples of the types of phosphate 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 re-mineralising phosphate source based on the total weight of the oral care composition. Preferably the level of sodium phosphate salt is from 1 to 20wt%, preferably 2 to 15 wt% of the total composition.

Compositions according to the invention preferably further comprise xanthan gum and/or carrageenan which can be present as structurants. It is particularly preferred that carrageenan is either iota or kappa carrageenan, a mixture of the two being particularly preferred.

It is preferred if the level of xanthan gum is from 0.1 to 0.9wt% of the total composition.

It is also preferred if the level of carrageenan is from is from 0.1 to 0.9wt% of the total composition. Preferably the weight ratio of xanthan gum to carrageenan is from 1 :2 to 2: 1. An alternative/additional structurant can include one or more solid polyethylene glycols having a melting point of 25°C or above. Preferably the melting point ranges from 35 to 65°C, more preferably from 55 to 60° C. Polyethylene glycols have the general formula H(OCH2CH2) _n OH, where n is the number of repeating oxyethylene units. Commercially available polyethylene glycols are usually not uniform chemical compounds, but instead consist of a distribution of similar polymer members of the homologous polyethylene glycol series, defined by average values of n and molecular weight. The melting point generally increases with increasing average values of n and molecular weight. Suitable solid polyethylene glycols have an average value of n in the above general formula ranging from about 20 to 220, preferably from about 40 to 150, more preferably from about 32 to 90, most preferably from about 60 to 75. The average molecular weight suitably ranges from about 950 to 11 ,250, preferably from about 1800 to 6600, more preferably from about 1400 to 4400, most preferably from about 2700 to 3700 g/mol. Suitable commercially available materials include for example Polyglykol® 3000 (ex Clariant). Mixtures of any of the above described materials may also be used.

The amount of solid polyethylene glycol (as defined above) if present in compositions of the invention suitably ranges from 0.1 to 5%, preferably from 0.5 to 3%, more preferably from 1 to 2.5% by total weight solid polyethylene glycol (as defined above) based on the total weight of the composition.

Preferably the composition comprises from 0.2 to 5wt% of the total composition of one or more surfactants, such as anionic, nonionic, cationic and zwitterionic or amphoteric surfactants. A preferred surfactant is a taurate, in particular sodium methyl cocoyl taurate. Alternatively sodium lauryl sulphate may be used.

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, dicalciumphosphates, 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 Evonik 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 copolymers 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.

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; bis-guanides, such as chlorhexidine digluconate, hexetidine, ethyl lauroyl arginate, 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, propyleneglycol, 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.

The Examples will now be illustrated by a the following non-limiting Examples. Examples of the invention are referred to by a number and comparative Examples by a letter.

Examples

Table 1

Composition according to the invention was applied to the teeth prior to placement of a retainer the teeth.