Oral care composition

Abstract

Disclosed herein are oral care compositions comprising calcium silicate, an uncharged polar amino acid, and a charged polar amino acid.

Description

Technical Field

[0001] The present invention relates to an oral care composition comprising calcium silicate and certain amino acids. The present invention also relates to a method for remineralizing an individual's teeth and / or preventing or reducing dental caries and / or reducing sensitivity by applying the composition to an individual's oral cavity. Background Art

[0002] Teeth include dentin, which is covered by an outer layer of enamel. Teeth are under constant erosion from chemical and physical forces, including bacteria-derived acids and mechanical wear, resulting in demineralization and weakening of the enamel and underlying dentin. Enamel consists of hydroxyapatite crystals that produce a porous surface. Tooth decay is initially detected in the enamel and may progress to the underlying dentin. There is a need to prevent or at least retard enamel decay to maintain good oral health. Fluoride is commonly used in oral care products to combat dental caries. The resulting fluorapatite composition is harder than the original hydroxyapatite composition and has a higher tolerance to acidic erosion.

[0003] Tooth hypersensitivity is a temporarily induced pain sensation that affects up to 20% of the adult population. This is associated with tooth demineralization and loss of enamel or cementum, thereby exposing the underlying dentin. The dentin of teeth generally contains channels, called tubules, which provide a permeating flow between the inner pulp region of the tooth and the outer root surface. The cause of tooth hypersensitivity may be related to demineralization, resulting in increased exposure of the tubules and permeability of the dentin. The most common causes of enamel or dentin demineralization are attrition, abrasion, gingival recession, and erosion. When the root surface is exposed, the dentin tubules are also exposed.

[0004] The currently accepted theory of tooth hypersensitivity is a hydrodynamic theory based on the recognition that open, exposed dentin tubules allow fluid to flow through the tubules. This flow stimulates nerve endings in the pulp. Clinical replicas of sensitive teeth observed in SEM (scanning electron microscope) reveal varying numbers of open or partially blocked dentin tubules.

[0005] For many years, efforts have been made to treat tooth hypersensitivity. One approach is to use "nerve depolarizing agents", including strontium ions, potassium salts such as potassium nitrate, potassium bicarbonate, potassium chloride, etc., to reduce the excitability of nerves in sensitive teeth. These nerve depolarizing agents act by interfering with the nerve transduction of pain stimuli to make the nerves less sensitive.

[0006] Another approach is to use "tubule blocking agents" that completely or partially block the tubules, such as polystyrene beads, apatite, polyacrylic acid, mineral hectorite clay, etc. These tubule blocking agents act by physically blocking the exposed ends of the dentin tubules, thereby reducing dentin fluid movement and reducing the stimuli associated with the shear stress described by the hydrodynamic theory.

[0007] There remains a need for improved oral care compositions for remineralizing teeth and / or preventing or reducing dental caries and / or occluding dentinal tubules to reduce tooth sensitivity. SUMMARY OF THE INVENTION

[0008] In a first aspect, the present invention relates to an oral care composition comprising:

[0009] a) calcium silicate;

[0010] b) an uncharged polar amino acid; and

[0011] c) a charged polar amino acid.

[0012] In a second aspect, the present invention relates to a packaged oral care product comprising the oral care composition of the first aspect of the present invention.

[0013] In a third aspect, the present invention relates to a method for remineralizing and / or preventing or reducing dental caries and / or reducing sensitivity of an individual's teeth, the method comprising the step of applying a composition of any embodiment of the first aspect to the oral cavity of an individual. The method is preferably for non-therapeutic benefits.

[0014] All other aspects of the present invention will become clearer when considering the following detailed description and examples. DETAILED DESCRIPTION

[0015] Unless in the examples, or explicitly stated elsewhere, all numbers in this specification indicating amounts of materials or reaction conditions, physical properties of materials, and / or uses may optionally be understood to be modified by the word "about".

[0016] Unless otherwise stated, all amounts are by weight of the final composition. It should be noted that when defining any numerical range, any particular upper value can be associated with any particular lower value.

[0017] For the avoidance of doubt, the word "comprising" is intended to mean "including", but not necessarily "consisting of" or "composed of". In other words, the listed steps or options need not be exhaustive.

[0018] The disclosure of the present invention as found herein should be considered to cover all embodiments found to be mutually multiply dependent in the claims, regardless of the fact that the claims may be found to have no multiple dependency or redundancy.

[0019] Where features are disclosed in relation to a particular aspect of the present invention (such as the compositions of the present invention), with the necessary modifications, such disclosure should also be considered applicable to any other aspect of the present invention (such as the methods of the present invention).

[0020] Within the scope of the present invention, the term "remineralization" refers to the production of calcium phosphate in situ (i.e., in the oral cavity) on teeth to reduce the likelihood of tooth sensitivity, dental caries, regenerate tooth enamel by producing the new calcium phosphate, and / or improve the appearance of teeth by whitening. Preferably, the new calcium phosphate layer on the teeth is 10 nm to 20 microns thick, more preferably 75 nm to 10 microns thick, and most preferably 150 nm to 5 microns thick, including all ranges therebetween.

[0021] Within the scope of the present invention, the term "oral care composition" refers to a composition that is delivered to the oral surfaces. The composition can be a product that, during normal use, is not intended for systemic administration or intentional swallowing, but rather is retained in the oral cavity for the purpose of oral activities for a time sufficient to contact substantially all tooth surfaces and / or oral tissues.

[0022] Examples of such oral compositions include toothpaste or dentifrice, mouthwash or gargle, powders (such as tooth powder), throat lozenges, mints, creams, strips or gums (such as chewing gum), films, topical oral gels, slurries, and denture cleaners, among others. Typically, the composition is packaged. In the form of toothpaste or gel, the composition can be packaged in a conventional plastic laminate, a metal tube, or a single-compartment dispenser. It can be applied to the tooth surface by any physical means, such as a toothbrush, fingertips, or directly to sensitive areas via an applicator. In the form of a liquid mouthwash, the composition can be packaged in a bottle, sachet, or other convenient container.

[0023] The compositions of the present invention are preferably used for cleaning oral surfaces. Accordingly, preferred product forms of the compositions of the present invention are those that are suitable for brushing and / or rinsing oral surfaces.

[0024] The compositions of the present invention are most preferably in the form of dentifrice or toothpaste. Within the scope of the present invention, the term "dentifrice" refers to an oral composition for cleaning oral surfaces. The composition is not intentionally swallowed for the purpose of systemic administration of a therapeutic agent, but is applied to the oral cavity for treating the oral cavity and then spat out. Typically, the composition is used together with a cleaning instrument such as a toothbrush, usually by applying it to the bristles of the toothbrush and then brushing the accessible surfaces of the oral cavity. Within the scope of the present invention, the term "toothpaste" refers to a paste or gel dentifrice that is used with a cleaning instrument such as a toothbrush. The dentifrice / toothpaste is preferably in an extrudable semi-solid form, such as a cream, paste, or gel (or a mixture thereof).

[0025] The calcium silicate applicable to the present invention may include tricalcium silicate, dicalcium silicate or tricalcium silicate. In a preferred embodiment, the calcium silicate used has low water solubility and can be commercially obtained from PQ Corporation under the trade name Sorbosil CA40. In another preferred embodiment, the calcium silicate is insoluble and exists as a composite material calcium oxide - silica (CaO - SiO2), as described, for example, in the international patent application published as WO 2008 / 01517 (Unilever), the entire content of which is incorporated herein by reference. For the calcium silicate composite material, the atomic ratio of calcium to silicon (Ca:Si) may be from 1:30 to 3:1. The Ca:Si ratio is preferably from 1:20 to 3:1, more preferably from 1:10 to 3:1, and most preferably about 1:7 to 3:1.

[0026] In addition to calcium oxide and silica, the particles containing the calcium silicate may contain other components, such as metal cations, anions (such as phosphate radicals), etc. However, preferably, the particles contain calcium oxide and silica in an amount of at least 70%, more preferably at least 80%, still more preferably at least 90% and even more preferably at least 95% by weight of the particles. Most preferably, the particles consist of (or at least consist essentially of) calcium oxide and silica.

[0027] In another preferred embodiment, the calcium silicate is calcium silicate hydrate. The calcium silicate hydrate used in the present invention contains at least calcium oxide (CaO), silica (SiO2) and water. Compared with conventional non - hydrated calcium silicate, the calcium silicate hydrate contains water of hydration in an amount of at least 5%, preferably at least 10%, more preferably at least 15%, even more preferably at least 20% and most preferably at least 25% by weight of the calcium silicate hydrate. By weight of the calcium silicate hydrate, the water content is typically not more than 50%, more preferably not more than 40%, even more preferably not more than 35% and most preferably not more than 30%. "Water of hydration" for the purposes of the present invention refers to water chemically bound to a substance in such a way that it can be removed by heating without substantially changing the chemical composition of the substance. Specifically, water that can only be removed when heated above 200 °C. The water loss is measured using a Netzsch TG instrument by thermogravimetric analysis (TGA). TGA is carried out at a heating rate of 10 degrees / min in the range of 30 to 900 °C in an N2 atmosphere.

[0028] The calcium silicate hydrate preferably contains at least 20%, more preferably at least 30%, still more preferably at least 40% and most preferably at least 55% by weight of the calcium silicate hydrate of silicon dioxide. The silicon dioxide content is preferably not more than 70% by weight of the calcium silicate hydrate, more preferably not more than 65% and most preferably not more than 60%. In order to provide the calcium required for remineralization, the calcium silicate hydrate preferably contains an amount of calcium oxide of at least 5%, more preferably at least 7%, still more preferably at least 10%, even more preferably at least 12% and most preferably at least 15% by weight of the calcium silicate hydrate. The calcium oxide content is typically not more than 50% by weight of the calcium silicate hydrate, more preferably not more than 40%, even more preferably not more than 30% and most preferably not more than 25%. The calcium silicate hydrate preferably contains Ca and Si with an atomic ratio (Ca:Si) of less than 1:1, more preferably less than 1:1.2, still more preferably 1:1.5 to 1:4 and most preferably 1:1.7 to 1:3. In addition to calcium oxide, silicon dioxide and water, the particles containing the calcium silicate hydrate may contain other components, such as metal cations, anions (such as phosphate radicals), etc. However, preferably, the particles contain an amount of CaO, SiO2 and water of at least 70%, more preferably at least 80%, still more preferably at least 90% and even more preferably at least 95% by weight of the particles. Most preferably, the particles consist of (or at least consist essentially of) CaO, SiO2 and water.

[0029] Preferably, the calcium silicate of the present invention is granular, which allows the largest surface area for contact with tooth tissue. The particle size of the calcium silicate used in the present invention is preferably from 100 nm to 50 μm, more preferably from 500 nm to 30 μm, still more preferably from 700 nm to 20 μm and most preferably from 1 μm to 15 μm. Within the scope of the present invention, the "particle size" refers to the D50 particle size. The D50 particle size of a granular material is the particle size diameter at which 50% by weight of the particles are larger in diameter and 50% by weight are smaller in diameter.

[0030] The calcium silicate may be crystalline, or amorphous, or mesoporous. In another preferred embodiment, the calcium silicate is at least partially crystalline. When the calcium silicate is partially crystalline, it contains calcium (Ca) and silicon (Si) with an atomic ratio (Ca:Si) of 1:3 to 3:1, more preferably 1:1.5 to 1.5:1 and most preferably 1:1.1 to 1.1:1. Preferably, the calcium silicate is completely crystalline. The presence of crystallinity can be confirmed, for example, by X-ray diffraction. An example of calcium silicate suitable for the present invention may The trade name M9000 is commercially available from NYCO Minerals, Inc.

[0031] The oral care composition typically comprises from 0.1 to 80% by weight, more preferably from 0.5 to 50% by weight, even more preferably from 1 to 30% by weight and most preferably from 3 to 20% by weight of the calcium silicate, based on the total weight of the oral care composition and including all ranges subsumed therein.

[0032] Amino acids are organic molecules consisting of a basic amino group (–NH2), an acidic carboxyl group (–COOH) and an organic side chain unique to each amino acid. Currently, 20 amino acids are known to exist in the standard genetic code, and others have been found in some bacteria (e.g., selenocysteine, pyrrolysine, ornithine). These 20 amino acids include alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine.

[0033] Amino acids can be divided into two groups: non-polar amino acids and polar amino acids. Polar amino acids have hydrophilic side chains, which can be further divided into three groups: uncharged (neutral) polar amino acids, positively charged polar amino acids and negatively charged polar amino acids.

[0034] The uncharged polar amino acids suitable for the present invention include, for example, serine, tyrosine, threonine, cysteine, asparagine, glutamine or mixtures thereof, preferably serine, tyrosine, cysteine or mixtures thereof. Tyrosine is particularly preferred.

[0035] The composition preferably comprises from 0.01 to 15%, more preferably from 0.1 to 10%, even more preferably from 0.5 to 8% and most preferably from 1 to 5% by weight of the composition of the uncharged polar amino acids, based on the total weight of the composition and including all ranges subsumed therein.

[0036] Preferably, the charged polar amino acids suitable for the present invention are positively charged polar amino acids, which include lysine, arginine, histidine, ornithine or mixtures thereof, and the positively charged polar amino acids preferably include or are lysine.

[0037] Particularly preferably, the uncharged polar amino acid is tyrosine and the charged polar amino acid is lysine.

[0038] Also preferably, the charged polar amino acids suitable for the present invention are a combination of positively charged polar amino acids and negatively charged polar amino acids. Suitable positively charged polar amino acids include lysine, arginine, histidine, ornithine, or mixtures thereof, and the positively charged polar amino acids preferably include or are lysine. Suitable negatively charged polar amino acids include aspartic acid, glutamic acid, or mixtures thereof, and the negatively charged polar amino acids preferably include or are glutamic acid. The combination preferably contains the positively charged polar amino acids and the negatively charged polar amino acids in a weight ratio of 1:20 to 10:1, more preferably 1:10 to 5:1.

[0039] In the composition, the charged polar amino acids are preferably present in an amount of 0.01 to 15%, more preferably 0.1 to 10%, even more preferably 0.5 to 8%, and most preferably 1 to 5% by weight of the composition, based on the total weight of the composition and including all ranges subsumed therein.

[0040] In the composition, the weight ratio of the uncharged polar amino acids to the charged polar amino acids is preferably 1:15 to 15:1, more preferably 1:10 to 10:1, and most preferably 1:5 to 5:1.

[0041] In the composition, the total amount of the uncharged polar amino acids and the charged polar amino acids is preferably 0.1 to 20%, more preferably 1 to 15%, even more preferably 2 to 10%, and most preferably 3 to 8% by weight of the oral care composition, based on the total weight of the oral care composition and including all ranges subsumed therein.

[0042] In addition to the uncharged polar amino acids and the charged polar amino acids, the composition of the present invention may contain other amino acids. Preferably, the composition is substantially free of other amino acids. In the context of the present invention, the term "substantially free of" means less than 0.005% by weight, preferably less than 0.001% by weight, more preferably less than 0.0005% by weight, and even more preferably 0 to 0.0005% by weight, based on the total weight of the composition and including all ranges subsumed therein. Preferably, the composition of the present invention is free of other amino acids except for the uncharged polar amino acids and the charged polar amino acids contained in the composition.

[0043] Preferably, the amount of calcium silicate in the composition is present in a weight ratio of 1:10 to 20:1, preferably 1:5 to 15:1, more preferably 1:3 to 13:1, and even more preferably 1:1 to 10:1 with the total amount of the uncharged polar amino acids and the charged polar amino acids, including all proportions subsumed therein.

[0044] The composition may comprise a phosphate source. The phosphate source is capable of providing phosphate ions to react with calcium silicate to form an in-situ reaction product of calcium phosphate, which is a precursor for the formation of hydroxyapatite. Preferably, the phosphate source is dissolved in water to obtain a phosphate ion concentration of at least 0.1 mol / L at room temperature and atmospheric pressure. Exemplary examples of the types of phosphate sources suitable for the present invention include trisodium phosphate, monosodium dihydrogen phosphate, disodium hydrogen phosphate, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, tripotassium phosphate, monopotassium dihydrogen phosphate, dipotassium hydrogen phosphate, mixtures thereof or the like.

[0045] The phosphate source may be present in the range of 0.1 to 30%, preferably 0.5 to 20%, more preferably 1 to 15% by weight of the composition, based on the total weight of the composition and including all ranges subsumed therein.

[0046] The calcium silicate and the phosphate source may be present in a weight ratio of 1:10 to 30:1, preferably 1:5 to 20:1, more preferably 1:3 to 15:1.

[0047] Preferably, the composition of the present invention is non-aqueous. It can improve the stability of many materials that are physically or chemically incompatible with an aqueous environment. For example, the presence of calcium silicate and a phosphate source in a single-phase aqueous composition can cause premature reaction of calcium and phosphate and lead to product instability. "Non-aqueous" generally means that water is not intentionally added to the composition in any significant amount. However, the term "non-aqueous" does not mean that a small amount of water may not be present, for example due to its association with hygroscopic raw materials. Thus, for the purposes of the present invention, the term "non-aqueous" generally means that water is present in an amount of no more than 5% by weight, more preferably no more than 3% by weight, based on the total weight of the composition.

[0048] Typically, the pH of the composition is from 5.5 to 10.5, more preferably from 6.0 to 10, and most preferably from 6.5 to 9.5. The pH of the composition can be measured when 5 parts by weight of the composition is uniformly dispersed and / or dissolved in 20 parts by weight of pure water at 25°C. Specifically, the pH can be measured by manually mixing 5 g of the composition with 20 mL of water for 30 seconds and then immediately testing the pH with an indicator or a pH meter, or the pH of the composition can be directly measured with a pH meter.

[0049] The composition of the present invention may further comprise a physiologically acceptable carrier. The carrier preferably comprises at least a surfactant, a thickening agent, a wetting agent or a combination thereof.

[0050] The composition preferably contains a surfactant. The composition preferably contains at least 0.01%, more preferably at least 0.1%, and most preferably 0.5 to 7% by weight of the composition of the surfactant. Suitable surfactants include anionic surfactants, such as the sodium, magnesium, ammonium, or ethanolamine salts of the following substances: C8 to C 18 alkyl sulfates (such as sodium lauryl sulfate), C8 to C 18 alkyl sulfosuccinates (such as dioctyl sodium sulfosuccinate), C8 to C 18 alkyl sulfacetates (such as sodium lauryl sulfacetate), C8 to C 18 alkyl sarcosinates (such as sodium lauryl sarcosinate), C8 to C 18 alkyl phosphates (optionally may contain up to 10 ethylene oxide units and / or propylene oxide units) and sulfated glycerol monoesters. Other suitable surfactants include nonionic surfactants, such as optionally polyethoxylated sorbitan fatty acid esters, ethoxylated fatty acids, esters of polyethylene glycol, ethoxylates of fatty acid monoglycerides and diglycerides, and ethylene oxide / propylene oxide block polymers. Other suitable surfactants include amphoteric surfactants, such as betaines or sulfobetaines. Mixtures of any of the above materials may also be used. The surfactant more preferably comprises or is an anionic surfactant. Preferred anionic surfactants are sodium lauryl sulfate and / or sodium dodecylbenzenesulfonate. The surfactant is most preferably sodium lauryl sulfate, sodium cocosulfate, cocamidopropyl betaine, sodium methyl cocoyl taurate, or a mixture thereof.

[0051] Thickeners can also be used in the present invention. Exemplary examples of the types of thickeners that can be used in the present invention include sodium carboxymethyl cellulose (SCMC), hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, tragacanth gum, gum arabic, karaya gum, sodium alginate, carrageenan, guar gum, xanthan gum, Irish moss, starch, modified starch, silica-based thickeners including silica aerogel, magnesium aluminum silicate (such as Veegum), carbomer (crosslinked acrylate), and mixtures thereof.

[0052] Typically, xanthan gum and / or sodium carboxymethyl cellulose and / or carbomer are preferred. When using carbomer, it is desirable that it has a weight average molecular weight of at least 700,000, preferably, it has a molecular weight of at least 1,200,000, and most preferably, it has a molecular weight of at least about 2,500,000. Mixtures of carbomer can also be used herein.

[0053] In a preferred embodiment, the carbomer is Synthalen PNC, Synthalen KP or a mixture thereof. It is described as a high molecular weight and cross-linked polyacrylic acid, identified by CAS number 9063-87-0. Materials of these types are commercially available from suppliers such as Sigma.

[0054] In another preferred embodiment, the sodium carboxymethyl cellulose (SCMC) used is SCMC 9H. It is described as the sodium salt of a cellulose derivative, having a carboxymethyl group bonded to the hydroxyl group of the glucopyranose backbone monomer, identified by CAS number 9004-32-4. It is available from suppliers such as Alfa Chem.

[0055] In another preferred embodiment, the thickener is xanthan gum.

[0056] In another particularly preferred embodiment, the thickener is carrageenan. Suitable carrageenans include iota and kappa carrageenan. Iota carrageenan and kappa carrageenan are preferably present in a weight ratio of 1:2 to 2:1. The carrageenan present in the composition of the present invention preferably consists of 33 to 66% by weight of iota carrageenan and 33 to 66% by weight of kappa carrageenan. The total content of carrageenan is preferably 0.05 to 1% by weight of the composition, more preferably 0.08 to 0.5% and most preferably 0.08 to 0.25% by weight of the composition. Iota carrageenan or kappa carrageenan is commercially available, for example, from CPKelco.

[0057] The thickener typically accounts for 0.01 to 10% by weight of the composition, more preferably 0.1 to 9% and most preferably 0.1 to 5%, based on the total weight of the composition and including all ranges subsumed therein.

[0058] Suitable wetting agents are preferably used in the composition of the present invention, which include, for example, glycerol, sorbitol, propylene glycol, dipropylene glycol, diglycerol, triacetin, mineral oil, polyethylene glycol (preferably PEG-400), alkanediols such as butanediol and hexanediol, ethanol, pentanediol or mixtures thereof. Glycerol, polyethylene glycol, sorbitol or mixtures thereof are preferred wetting agents.

[0059] The wetting agent may be present in the range of 10 to 90% by weight of the composition. More preferably, the carrier wetting agent accounts for 25 to 80% by weight of the composition, most preferably 30 to 60%, based on the total weight of the composition and including all ranges subsumed therein.

[0060] The composition may comprise a fluoride source. Preferred fluoride sources include sodium fluoride, stannous fluoride, potassium fluoride, sodium monofluorophosphate, sodium fluorosilicate, ammonium fluorosilicate, amine fluoride, ammonium fluoride, or mixtures thereof. Preferably, the fluoride source is stannous fluoride, sodium fluoride, sodium monofluorophosphate, or mixtures thereof. Sodium monofluorophosphate is particularly preferred. The fluoride source may be present in an amount of 0.01 to 10%, more preferably 0.03 to 5%, and most preferably 0.1 to 2% by weight of the composition, based on the total weight of the composition and including all ranges subsumed therein.

[0061] The composition may comprise a particulate abrasive material such as silica, alumina, calcium carbonate, dicalcium phosphate, calcium pyrophosphate, hydroxyapatite, trimetaphosphate, insoluble hexametaphosphate, etc., including agglomerated particulate abrasive materials. The abrasive may be present in an amount in the range of 0.01 to 60%, more preferably 0.1 to 30%, and most preferably 1 to 15% by weight of the composition, based on the total weight of the composition and including all ranges subsumed therein.

[0062] The composition, particularly toothpaste, preferably comprises a silica-based abrasive. The preferred abrasive silica used in the present invention is silica having a low refractive index. It may be used as the sole abrasive silica or together with a low content of other abrasive silicas such as those according to EP 236 070. The low refractive index silica used as an abrasive in the present invention preferably has the following properties: an apparent refractive index (R.I.) of 1.41 to 1.47, preferably 1.435 to 1.445, preferably having a weight average particle size of 5 to 15 mm, a BET (nitrogen) surface area of 10 to 100 m 2 / g, and an oil absorption of 70 to 150 cm 3 / 100 g, but abrasive silicas having a lower apparent refractive index may also be used. Typical examples of suitable low refractive index abrasive silicas (e.g., having an R.I. of 1.435 to 1.445) are Tixosil 63 and 73, from Rhone Poulenc; Sident 10, from Degussa; Zeodent 113, from Zeofinn; Zeodent 124, from Evonik; Sorbosil AC 77, from PQ Corporation (R.I. of about 1.440). The amount of these silicas in the composition is generally 5 to 60% by weight, usually 5 to 20% by weight.

[0063] The composition may comprise a polymer deposition aid. The composition preferably comprises an acid anhydride polymer, particularly preferably a copolymer of maleic anhydride and methyl vinyl ether, wherein the anhydride moiety may be in a partially or fully hydrolyzed or alcoholyzed form. Preferred copolymers include Gantrez(R) polymers, such as:

[0064] Gantrez S-95: molecular weight 216,000; free acid;

[0065] Gantrez S-96: molecular weight 700,000; free acid;

[0066] Gantrez S-97: molecular weight 1,500,000; free acid; and

[0067] Gantrez MS-955: molecular weight 1,060,000; calcium / sodium salt.

[0068] Particularly preferred copolymers of maleic acid and methyl vinyl ether have a molecular weight of 1,000,000 or greater, and a particularly preferred material is Gantrez S-97.

[0069] The composition may comprise a tooth whitening agent. The whitening agent preferably comprises a green and / or blue pigment. Within the scope of the present invention, a pigment is generally understood to be a shade / material that is insoluble in the relevant medium at the relevant temperature. This is different from a soluble dye. Within the scope of the present invention, the "relevant medium" is human saliva, the liquid medium in which the composition is used, at the temperature of the oral cavity during tooth brushing, i.e., up to 37 °C. As a reasonable approximation, the relevant medium can be considered to be water, and the relevant temperature can be considered to be 25 °C.

[0070] The blue pigment is preferably Pigment Blue 15, more preferably Pigment Blue 15:1, 15:2, 15:3, 15:4, 15:5 or 15:6, and most preferably 15:1. A preferred pigment is a blue pigment, phthalocyanine blue pigment, CI No. 74160, bluecovarine.

[0071] The preferred green pigment is phthalocyanine green, preferably phthalocyanine green CI-74260.

[0072] The total content of the pigment in the composition is preferably 0.01 to 3% by weight of the composition, more preferably 0.02 to 2%.

[0073] The composition may comprise a water-soluble or water-insoluble metal salt source. Preferably zinc ions, such as zinc chloride, zinc acetate, zinc gluconate, zinc sulfate, zinc fluoride, zinc citrate, zinc lactate, zinc oxide, zinc monoglycerate, zinc tartrate, zinc pyrophosphate and zinc maleate; also preferably stannous ions, such as stannous fluoride and stannous chloride.

[0074] The composition may comprise an oral care enzyme system, such as an enzyme system that generates hydrogen peroxide (e.g., the redox enzyme glucose oxidase), amyloglucosidase, dextranase, and / or mutanase (optionally in the presence of a compound providing zinc ions and / or an 8-hydroxyquinoline derivative), lactoperoxidase, lactoferrin, lysozyme, and mixtures thereof;

[0075] Mixtures of any of the above materials may also be used.

[0076] In addition to the above ingredients, the compositions of the present invention may comprise many other ingredients commonly used in the prior art to improve physical properties and characteristics, such as:

[0077] Antimicrobials, such as chlorhexidine, sanguinarine extract, metronidazole, quaternary ammonium compounds, such as cetylpyridinium chloride; cetylpyridinium chloride clay complex biguanides, such as chlorhexidine digluconate, hexetidine, octenidine, alexidine; and halogenated bisphenol compounds, such as 2,2'-methylenebis-(4-chloro-6-bromophenol);

[0078] Anti-inflammatory agents, such as ibuprofen, flurbiprofen, aspirin, indomethacin, etc.;

[0079] Anticariogenic agents, such as sodium fluoride and stannous fluoride, amine fluoride, sodium monofluorophosphate, trimetaphosphate, and casein;

[0080] Dental plaque buffers, such as urea, calcium lactate, calcium glycerophosphate, and strontium polyacrylate;

[0081] Vitamins, such as vitamins A, C, and E;

[0082] Plant extracts;

[0083] Plant-derived antioxidants, such as flavonoids, catechins, polyphenols, and tannin compounds and mixtures thereof;

[0084] Desensitizing agents, such as potassium citrate, potassium chloride, potassium tartrate, potassium bicarbonate, potassium oxalate, potassium nitrate, and strontium salts;

[0085] Anticalculus agents, such as alkali metal pyrophosphates, hypophosphite-containing polymers, organic phosphonates, and phosphonyl citrates, etc.;

[0086] Biomolecules, such as bacteriocins, antibodies, enzymes, etc.;

[0087] Flavoring agents, such as peppermint oil and spearmint oil;

[0088] Proteinaceous materials, such as collagen;

[0089] Preservatives;

[0090] Opacifier;

[0091] Hyaluronic acid;

[0092] Colorant;

[0093] pH regulator;

[0094] Sweetener;

[0095] It may also contain polymeric compounds that can improve the delivery of active ingredients such as microbicides; buffers and salts, which are used to buffer the pH and ionic strength of the oral care composition; and

[0096] other optionally present ingredients that may be included, such as bleaching agents, such as peroxides, such as potassium peroxydiphosphate, foaming systems, such as sodium bicarbonate / citric acid systems, color-changing systems, etc.

[0097] These ingredients typically and together account for less than 20% by weight of the composition, preferably 0.0 to 15% by weight, most preferably 0.01 to 12% by weight of the composition, including all ranges included therein.

[0098] The oral care composition of the present invention can be used in a method for remineralizing and / or preventing or reducing dental caries and / or reducing sensitivity of an individual's teeth. The method includes applying the oral care composition of the present invention to the oral cavity of an individual in need, such as by brushing, such as once or more times a day. Preferably, the method is non-therapeutic.

[0099] Additionally or alternatively, the present invention relates to an oral care composition for remineralizing and / or preventing or reducing dental caries and / or reducing sensitivity of an individual's teeth. Additionally or alternatively, the present invention relates to the use of an oral care composition for remineralizing and / or preventing or reducing dental caries and / or reducing sensitivity of an individual's teeth, which use is preferably non-therapeutic. Additionally or alternatively, the present invention relates to the use of an oral care composition in the preparation of a medicament for remineralizing and / or preventing or reducing dental caries and / or reducing sensitivity of an individual's teeth.

[0100] Additionally, administering the compositions of the present invention to an individual's oral cavity can provide one or more of the following benefits: reducing plaque accumulation; inhibiting the formation of microbial biofilms in the oral cavity; reducing or inhibiting gingivitis; promoting the healing of oral ulcers or wounds; reducing the level of acid-producing bacteria; increasing the relative level of non-cariogenic and / or non-plaque-forming bacteria; reducing, repairing, or inhibiting pre-carious lesions of tooth enamel; treating, alleviating, or reducing dry mouth; cleaning teeth and the oral cavity; reducing erosion; whitening teeth; reducing tartar accumulation; and / or promoting overall health, including cardiovascular health, for example, by reducing the potential for systemic infections via oral tissues. The present disclosure further provides compositions for any of the above methods.

[0101] The compositions can be effective even when used in an individual's daily oral hygiene routine. For example, the compositions can be brushed onto the teeth. The compositions can be in contact with the teeth, for example, for a period of from 1 second to 20 hours, more preferably from 1 second to 10 hours, still more preferably from 10 seconds to 1 hour, and most preferably from 30 seconds to 5 minutes. The compositions can be used daily, for example, once, twice, or three times a day by an individual.

[0102] The following examples are given to facilitate understanding of the present invention. These examples are provided without limiting the scope of the claims.

[0103] Examples

[0104] Example 1

[0105] Compositions were prepared as shown in Table 1. All ingredients are expressed as weight percentages of the total formulation.

[0106] Table 1

[0107]

[0108] a. Calcium silicate commercially obtained from P.Q. Corporation under the trade name Sorbosil CA40

[0109] Evaluating reduction in surface microhardness (SMH) of tooth enamel

[0110] Fresh toothpaste slurries were prepared by mixing 4 grams of toothpaste sample with 8 mL of deionized (DI) water for 40 seconds and used immediately.

[0111] The surface microhardness (SMH) of enamel was measured using a microhardness tester (Struers Durascan) with a Knoop indenter at a load of 50 gf for 10 seconds. For each enamel block, five indentations were made in different regions at each test point to avoid residual stress. To evaluate the microhardness of enamel, finely polished human enamel blocks were divided into four groups (n = 5 in each group) with similar SMH reference values. The SMH of the human enamel blocks was measured and denoted as SMH baseline The human enamel blocks were soaked in freshly prepared toothpaste slurry for 3 minutes, then placed in a demineralization solution (Demin solution) at 37 °C with gentle shaking for 4 hours, and then rinsed with water. Then, the enamel blocks were soaked in a remineralization solution (Remin solution) at 37 °C with gentle shaking for 4 hours. The whole treatment within one day was called a one-day treatment cycle. The treatment was repeated for 7 days, and the SMH of the enamel blocks was measured and denoted as SMH treated .

[0112] The Demin solution consisted of: 2 mM CaCl2, 2 mM KH2PO4, 75 mM acetic acid, 0.1 mM Tris buffer, and the pH was adjusted to 4.6 using 1 M KOH.

[0113] The Remin solution consisted of: 1.5 mM CaCl2, 0.9 mM KH2PO4, 150 mM KCl, and 20 mM HEPES, adjusted to pH 7.0 with NaOH.

[0114] The reduction in the surface microhardness (SMH) of enamel was calculated as follows:

[0115] SMH reduction (%) = (SMH treated – SMH baseline ) × 100 / SMH baseline

[0116] The results are shown in Table 2.

[0117] Table 2

[0118]

[0119] As can be seen in Table 2, the enamel blocks treated with Sample 1 had higher tolerance to acid erosion, indicating better protection of enamel against acid corrosion.

[0120] Evaluating the occluding effect of dentinal tubules

[0121] Fresh toothpaste slurry was prepared by mixing 4 g of toothpaste sample with 8 mL of deionized (DI) water for 40 seconds and used immediately.

[0122] Etch human dentin discs with 6% citric acid for 2 minutes and then treat with different slurries by brushing according to the same protocol. Divide eight human dentin discs into four groups (n = 2). Use a tooth brushing machine equipped with a toothbrush to brush the dentin discs with the slurries. The tooth brushing load is 170 g + / – 5 g and automatic brushing is performed at a rate of 150 rpm. After brushing for 1 minute, immerse the dentin discs in the slurry for 1 minute. Then place the dentin discs in 50 mL of DI water and agitate on a flatbed shaker for 10 strokes at 150 rpm. Then soak these discs in simulated oral fluid (SOF) under shaking water bath conditions at 37 °C and 60.0 rpm for at least 6 hours. Then, use the machine to brush the dentin discs with the slurries using the same procedure as the first step. Repeat brushing twice a day and then keep the dentin discs in SOF in a shaking water bath at 37 °C overnight (> 12 hours) to mimic the oral environment. Characterize the dentin samples using a scanning electron microscope (SEM, Hitachi S-4800, Japan) after one day of brushing.

[0123] Prepare simulated oral fluid by combining the ingredients in Table 3:

[0124] Table 3

[0125] Component Amount / g NaCl 16.07 <![CDATA[NaHCO3]]> 0.7 KCl 0.448 <![CDATA[K2HPO4·3H2O]]> 3.27 <![CDATA[MgCl2·6H2O]]> 0.0622 1M HCl 40 mL <![CDATA[Calcium chloride]]> 0.1998 <![CDATA[Na2SO4]]> 0.1434 Buffer Adjust the pH to 7.0 Water Make up the balance to 2 L

[0126] Regardless of the original shape of the dentin discs, select a square (sized 4 mm × 4 mm) and take an image at 30x magnification. Select five points within this square (each with a size of 150 μm × 150 μm, one in the middle and one at each corner) and observe at 1000x magnification. Evaluate the tubule occlusion according to the criteria described in Table 4. Perform measurements on two dentin discs for each test group.

[0127] Table 4

[0128] Score Tubule blockage 0 All dentinal tubules are open 1 <20% of the dentinal tubules are completely blocked 2 20 to 50% of dentinal tubules are completely blocked 3 50 to 80% of dentinal tubules are completely blocked 4 80 to 100% of dentinal tubules are completely blocked 5 All dentinal tubules are completely blocked

[0129] Take SEM images of the dentin discs after one day of brushing. Analyze and score the images. The results are reported in Table 5.

[0130] Table 5

[0131]

[0132] Compared with Comparative Samples A, B, and C, Sample 1 according to the present invention provides better tubule occlusion effect.

Claims

1. An oral care composition comprising: a) calcium silicate; b) an uncharged polar amino acid; and c) a charged polar amino acid.

2. The oral care composition according to claim 1, wherein the uncharged polar amino acid comprises serine, tyrosine, threonine, cysteine, asparagine, glutamine or a mixture thereof, preferably serine, tyrosine, cysteine or a mixture thereof, more preferably tyrosine.

3. The oral care composition according to claim 1 or claim 2, wherein the charged polar amino acid is a positively charged polar amino acid, which comprises lysine, arginine, histidine, ornithine or a mixture thereof, preferably lysine.

4. The oral care composition according to claim 1 or claim 2, wherein the charged polar amino acid is a combination of a positively charged polar amino acid and a negatively charged polar amino acid.

5. The oral care composition according to claim 4, wherein the positively charged polar amino acid comprises lysine, arginine, histidine, ornithine or a mixture thereof, preferably lysine.

6. The oral care composition according to claim 4, wherein the negatively charged polar amino acid comprises aspartic acid, glutamic acid or a mixture thereof, preferably glutamic acid.

7. The oral care composition according to any one of the preceding claims, wherein the uncharged polar amino acid and the charged polar amino acid are present in the composition in a weight ratio of 1:15 to 15:1, preferably 1:10 to 10:

1.

8. The oral care composition according to any one of the preceding claims, wherein the uncharged polar amino acid is tyrosine and the charged polar amino acid is lysine.

9. The oral care composition according to any one of the preceding claims, wherein the total amount of the uncharged polar amino acid and the charged polar amino acid in the composition is 0.1 to 20%, preferably 1 to 15%.

10. The oral care composition according to any one of the preceding claims, wherein the calcium silicate comprises Ca and Si in an atomic ratio of 1:30 to 3:1, preferably 1:20 to 3:

1.

11. The oral care composition according to any one of the preceding claims, wherein the calcium silicate is present in an amount of 0.1 to 80%, preferably 0.5 to 50% by weight of the composition.

12. The oral care composition according to any one of the preceding claims, wherein the amount of calcium silicate and the total amount of the uncharged polar amino acid and the charged polar amino acid are present in a weight ratio of 1:10 to 20:1, preferably 1:5 to 15:

1.

13. The oral care composition according to any one of the preceding claims, wherein the composition further comprises a phosphate source.

14. The oral care composition according to any one of the preceding claims, wherein the composition is a non-aqueous composition.

15. A method for remineralizing the teeth of an individual and / or preventing or reducing dental caries and / or reducing sensitivity, the method comprising the step of applying the composition according to any one of the preceding claims to the oral cavity of an individual.

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