Oral care composition

Abstract

The present invention relates to oral care compositions. There is a need to provide an oral care composition that remineralizes and at the same time prevents or at least reduces demineralization. The inventors of the present invention have observed that the combination of 1: 1 phyllosilicate clay, 2: 1 phyllosilicate clay and xanthan gum has a synergistic effect and they together remineralize teeth, preferably reduce their demineralization.

Description

TECHNICAL FIELD

[0001] The present invention relates to oral care compositions. In particular, the present invention relates to compositions for remineralisation. BACKGROUND

[0002] Abradants used in oral care compositions, such as dentifrices, need to be effective at removing extrinsic stains, plaque and food debris that accumulate on the pellicle on the surface of the teeth.

[0003] Generally, the efficiency of physically removing stains, plaque and food debris can be increased by using an abradant with a higher abrasivity, or by increasing the amount of abradant incorporated into the composition. However, both of these approaches also increase the risk of damage to the surface of the teeth.

[0004] The main component of enamel and dentin in teeth is calcium phosphate in the form of hydroxyapatite.

[0005] In the oral cavity, there is a natural balance between hydroxyapatite being dissolved from the enamel of the teeth and hydroxyapatite being formed on or in the teeth from naturally occurring substances in saliva. This balance is constantly changing. It is determined by, amongst other things, diet and physical condition.

[0006] If the balance is such that hydroxyapatite is being dissolved, then cariogenic conditions arise, which is known as demineralisation. Exposure of the hard tissues of the teeth to acid causes demineralisation, resulting in a softening of the surface and a reduction in mineral density. Dental erosion, which is acid erosion or acid wear, is a surface phenomenon that involves the demineralisation and eventual complete dissolution of the tooth surface by acids of non-bacterial origin. Most commonly, the acid will be of dietary origin. Dental erosion is becoming more prevalent and common as a result of today's lifestyle involving increased consumption of acidic beverages and foods.

[0007] If the balance is such that hydroxyapatite is being formed, then this is known as remineralisation. Remineralisation hardens and strengthens the teeth, providing protection and treatment against dental erosion and / or dental wear. It also reduces the likelihood of dental decay and improves the appearance of the teeth, particularly their whiteness. As a result, the teeth can also appear smoother and glossier.

[0008] The presence of fluoride ions can enhance the natural process of remineralisation, and this is one of the accepted mechanisms by which fluoride toothpastes and mouthwashes prevent dental caries. Fluoride is most effective during the developmental years from childhood to young adulthood.

[0009] However, the ability of fluoride to promote remineralisation can be limited by the availability of calcium and phosphate ions in saliva.

[0010] WO2014170096 A1 (Unilever) discloses a toothpaste composition comprising a calcium based abrasive; a humectant and up to 2wt% of a thickening silica, wherein the composition comprises 0.2wt% to 3wt% of a smectite clay. The composition provides superior sensory properties, as well as increased uptake of antibacterial agents by oral tissue.

[0011] WO2013007571 A2 (Unilever) discloses a toothpaste comprising a balanced amount of a calcium based abrasive, a copolymer of vinyl methyl ether and maleic acid and a clay is stable even at elevated temperatures. The composition can be formulated without any thickening silica. The ratio of the calcium based abrasive to the copolymer of vinyl methyl ether and maleic acid is at least 1 :0.075 and the ratio of the calcium based abrasive to the clay is at least 1 :0.02.

[0012] WO2020212361 A1 (Unilever) discloses a non-aqueous toothpaste comprising a polysaccharide (in particular xanthan gum) and calcium carbonate to reduce the relative dentin abrasion (RDA) while not reducing the cleaning efficiency (PCR).

[0013] There is a need for oral care compositions that can provide remineralization and at the same time prevent or at least reduce demineralization. SUMMARY

[0014] The inventors of the present invention have observed that a combination of 1 :1 phyllosilicate clay, 2:1 phyllosilicate clay and xanthan gum has a synergistic effect and they together remineralize the teeth and reduce their demineralization.

[0015] According to a first aspect of the present invention, there is disclosed an oral care composition comprising: i. an abrasive selected from a calcium based abrasive, a silica based abrasive or a mixture thereof; ii. 0.1wt% to 5wt% of a 1 :1 phyllosilicate clay; and, iii. 0.1wt% to 5wt% of a 2:1 phyllosilicate clay; wherein the composition comprises 0.1wt% to 5wt% of xanthan gum.

[0016] According to a second aspect of the present invention, there is disclosed a composition according to the first aspect for use in promoting remineralization of teeth.

[0017] According to a third aspect of the present application, disclosed is the use of 0.1 wt% to 5 wt% of xanthan gum, 1 : 1 phyllosilicate clay, 2: 1 phyllosilicate clay in an oral care composition for promoting remineralization of the teeth, said oral care composition comprising an abrasive, said abrasive being selected from a calcium based abrasive, a silica based abrasive or a mixture thereof.

[0018] According to the present application, the term "remineralization" refers to the in situ generation of hydroxyapatite on the teeth. DETAILED DESCRIPTION

[0019] According to a first aspect of the present application, disclosed is an oral care composition comprising an abrasive, a 1 : 1 phyllosilicate clay, a 2: 1 phyllosilicate clay and xanthan gum.

[0020] Oral care composition The disclosed oral care composition can take any product form suitable for application to the surface of the teeth, preferably in admixture with water. Examples of such product forms include solid forms such as powders or discrete unit doses (e.g. pellets, pastilles, tablets, etc.).

[0021] Preferably, the composition is in the form of a dentifrice. The term "dentifrice" denotes an oral composition used for cleaning the surfaces of the oral cavity. Such compositions are not intentionally swallowed for purposes of systemic delivery of therapeutic agents, but rather are applied to the oral cavity for treatment of that cavity and then expectorated. Typically, such compositions are 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.

[0022] The dentifrice used in the present application is suitably in the form of an extrudable semi-solid, such as a cream, a paste or a gel (or a mixture thereof). In one aspect of the present application, the oral care composition is a dentifrice composition, more preferably a toothpaste.

[0023] Alternatively, the composition of the present application preferably comprises a first dentifrice composition and a second dentifrice composition, wherein the first composition comprises a silica based abrasive and the second composition comprises a calcium based abrasive. These two types of compositions can preferably be presented in the form of a multi-phase composition, such as a core-&-sheath type or a side-by-side form. Alternatively, the composition can be provided in the above-mentioned forms (such as a core-&-sheath type) by a packaging scheme.

[0024] Alternatively, a consumer can be provided with a kit in which an anhydrous oral care composition as described above is packaged with a separate aqueous activator. The viscosity of the dentifrice is typically in the range of 10,000 to 100,000 cps, preferably in the range of 30,000 to 60,000 cps, when measured at 25°C on a Brookfield viscometer.

[0025] Preferably, the pH of the oral care composition is from 6.0 to 10.0, preferably from 6.5 to 9.5, more preferably from 6.5 to 9.0, even more preferably from 7.0 to 8.0, when measured using a 1 wt% aqueous solution of the oral care composition in distilled water, and as measured using a conventional pH sensitive electrode at 25°C.

[0026] The compositions, particularly dentifrices, for use in the present application will typically also comprise other ingredients to enhance performance and / or consumer acceptability.

[0027] Friction agents According to a first aspect of the present application, there is disclosed an oral care composition comprising an abrasive. According to the first aspect, the abrasive is selected from a calcium based abrasive, a silica based abrasive or a mixture thereof.

[0028] The disclosed oral care composition comprises from 3 wt% to 75 wt% of an abrasive. Suitable abrasive cleaning agents include silica xerogels, hydrogels and aerogels and precipitated particulate silicas; calcium carbonate, dicalcium phosphate, tricalcium phosphate, calcined alumina, sodium and potassium metaphosphates, sodium and potassium pyrophosphates, sodium trimetaphosphate, sodium hexametaphosphate, particulate hydroxyapatite and mixtures thereof.

[0029] In one aspect of the present application, the abrasive is a silica based abrasive. When the dentifrice composition of the present application is a gel toothpaste, it preferably comprises from 3 wt% to 20 wt% of silica, more preferably from 4 wt% to 15 wt%, most preferably from 4 wt% to 10 wt% of silica.

[0030] Such toothpastes are typically clear gels or translucent gels. The term "gel" refers to the physical appearance of the composition. The gel compositions are transparent to light, i.e. they allow visible light to pass through. Clear gel toothpastes are popular with consumers.

[0031] When the oral care composition of the present application is a toothpaste in the form of a gel, it is preferred that the composition does not comprise more than 5 wt%, preferably more than 2 wt%, more preferably more than 1 wt% of a calcium based abrasive. It can affect the transparent nature of the composition.

[0032] Further preferably, the abrasive silica comprises a medium abrasive silica and a high abrasive silica, with the medium abrasive silica preferably predominating. Their relative proportions can vary. Preferably, the abrasive silica is a low refractive index silica having an apparent refractive index in the range 1.41 to 1.47, preferably 1.435 to 1.445, preferably having a weight average particle size between 5 and 15 μm, 10 to 100 μm 2 BET (nitrogen) surface area of between 1 and 10 m 3 / g and an oil absorption of about 70 to 150 cm Examples of suitable low refractive index abrasive silicas having an R.I. of between 1.435 and 1.445 are Tixosil 63 and 73 from Rhone Poulenc; Sident 10 from Degussa; Zeodent 113 from Zeofinn; Sorbosil AC 77 from Ineos, having an R.I. of about 1.440. Other examples include abrasive silicas from the Sylodent® and Syloblanc® range from Grace.

[0033] Preferably, the abrasive silica is a precipitated silica. Suitable precipitated silicas for use as abrasive amorphous silica particles in the present application are commercially available and include those sold by PQ Corporation under the trade name SORBOSIL® AC 43, AC 77, AC 35 and SORBOSIL® AC 33. Mixtures of any of said materials can also be used. Preferably, the toothpaste composition comprises 1 wt% to 10 wt% abrasive silica. Examples of abrasives include abrasive amorphous silica particles having a weight average particle size (d50) in the range 3 to 15 microns. Preferred abrasive amorphous silica particles for use in the compositions of the present application have a weight average particle size in the range 3 to 6 microns. Preferably, the abrasive amorphous silica particles employed are precipitated silicas.

[0034] Preferably, when the abrasive is a silica based abrasive, the oral care composition comprises at least 1 wt%, preferably at least 2 wt%, still preferably at least 2.5 wt%, most preferably at least 4 wt%, but generally not more than 10 wt%, still preferably not more than 9 wt%, still further preferably not more than 8 wt%, most preferably not more than 7 wt% of a silica based abrasive.

[0035] On the other hand, there are some other types of toothpaste type dentifrice compositions which are not gels, but are opaque. This is because such compositions typically contain an opacifying ingredient, such as chalk or other calcium based abrasives.

[0036] Alternatively, the dentifrice composition of the present application comprises a calcium based abrasive. When the dentifrice composition of the present application comprises a calcium based abrasive, it preferably comprises 10wt% to 50wt% of abrasive, more preferably 10wt% to 45wt%, further preferably 20wt% to 40wt% of calcium based abrasive.

[0037] A particularly preferred calcium based abrasive is fine ground natural chalk (FGNC). It is obtained from limestone or marble. FGNC can also be chemically or physically modified by heat treatment during milling or by coating after milling. Typical coating materials include magnesium stearate and magnesium oleate. The morphology of FGNC can also be modified during the milling process by using different milling techniques, for example, ball milling, air classification milling or spiral jet milling. FGNC can be used as the only calcium containing abrasive. However, FGNC can also be used together with other calcium containing abrasives to balance the abrasivity. Other preferred calcium containing abrasives include dicalcium phosphate (DCP), calcium pyrophosphate and precipitated calcium carbonate (PCC). When a combination of calcium containing abrasives is used, it is preferred that FGNC makes up 35 to 100%, more preferably 75 to 100%, in particular 95 to 100% of the total abrasive. In this case, the balance is most preferably PCC.

[0038] 1 : 1 Layered silicate clay According to a first aspect of the present application, it is disclosed an oral care composition comprising a 1 : 1 layer silicate clay.

[0039] Preferably, the 1 : 1 layer silicate is a kaolinite. Preferably, the kaolinite is selected from the group consisting of kaolin, halloysite, nacrite and dickite. More preferably, it is kaolin. Kaolinite has di-octahedral sheets and the species contained within the kaolinite subgroup are kaolinite, dickite, nacrite and halloysite clay minerals, but are not limited thereto. Serpentine is a tri-octahedral sheet mineral having tetrahedral sheets and octahedral sheets with magnesium and a small amount of aluminium and the species within this subgroup are preferably antigorite, lizardite and chrysotile.

[0040] Kaolin (also known as kaolinite) is a naturally occurring mineral. Preferred kaolin is a hydrated aluminium silicate and is represented as AI2O3-2SiO2-2H2O. Preferred kaolinite has a particle size distribution such that at least 98wt% of the particles have a particle size of 2μm or less. Preferably, the 1 : 1 layered silicate clay is non-swellable.

[0041] Kaolinite has dioctahedral sheets and the materials included in the kaolinite subgroup are kaolinite, dickite, nacrite and halloysite clay minerals, but are not limited thereto. Kaolinite is particularly preferred in the present invention. Kaolinite, commonly known as kaolin clay, is a naturally occurring mineral. The kaolinite can be calcined kaolin, highly purified calcined kaolin, colloidal kaolin or hydrous kaolin, but is not limited thereto. Preferred kaolinite is a hydrated aluminium silicate and is represented as AI2O3-2SiO2-2H2O. Preferred kaolinite has a particle size distribution such that at least 98wt% of the particles have a particle size of 2μm or less. Preferably, the kaolinite is a refined kaolin, further preferably the refined kaolin comprises 38wt% AI2O3and 45wt% SiO2and at most 0.5wt% Fe2O3.

[0042] The oral care composition comprises 0.01wt% to 5wt% of the 1 : 1 layered silicate clay, more preferably 0.1wt% to 5wt% of the 1 : 1 layered silicate clay. Preferably, the dentifrice composition comprises 0.01wt% to 5wt% of the 1 : 1 layered silicate clay, more preferably 0.1wt% to 3wt%, still more preferably 0.1wt% to 2wt%, most preferably 0.1wt% to 1wt% of the 1 : 1 layered silicate clay.

[0043] 2: 1 Layered silicate clay According to a first aspect of the present invention, there is disclosed an oral care composition comprising a 2: 1 layered silicate clay.

[0044] The oral care composition according to the present application comprises a 2:1 layered silicate clay. Preferably, the 2:1 layered silicate is a smectite clay. Preferably, the 2:1 layered silicate clay is selected from the group consisting of phyllosilicates, montmorillonites, bentonites, hectorites, sodium magnesium silicate, magnesium aluminum silicate, organically modified smectites, and organically modified montmorillonite clays. The phyllosilicate-talc group preferably includes talc, which is a hydrated magnesium silicate; pyrophyllite, which is a hydrated aluminum silicate; or minnesotaite, which is a hydrated iron silicate. The vermiculite group of clays preferably includes di-octahedral vermiculite or tri-octahedral vermiculite. The tri-octahedral vermiculite preferably has a layer charge of 0.6 to 0.7.

[0045] It is highly preferred that the 2:1 layered silicate clay is a smectite group clay, which includes but is not limited to montmorillonite, smectite, beidellite, nontronite, saponite, hectorite, sauconite, or laponite. The smectite group clay is preferably di-octahedral smectite or tri-octahedral smectite.

[0046] Examples of suitable di-octahedral smectites include but are not limited to montmorillonite (commonly known as bentonite), smectite, beidellite, nontronite.

[0047] Generally, montmorillonite and smectite have a low total charge content of 0.3 to 0.6, and the majority of the charge originates from the octahedral sheets. Beidellite is an expandable di-octahedral smectite with a total charge content of 0.7 or higher, and a tetrahedral charge content of 0.4. When the di-octahedral smectite is montmorillonite, it is generally carbonate-free, and is preferably water-washed.

[0048] Examples of suitable tri-octahedral smectites include but are not limited to saponite, hectorite, sauconite, and laponite. Tri-octahedral smectites with a total charge content of 0.3 to 0.5 include hectorite and saponite. The hectorite has magnesium and lithium in the octahedral sheets, and the saponite has a substantial amount of magnesium in the octahedral sheets and some aluminum substitution in the tetrahedral sheets.

[0049] Particularly preferred 2:1 layered clays are clays of the smectite group, which can be derived from natural sources, processed or purified from natural sources, or synthetically prepared. More preferably, the 2:1 layered silicate clay is magnesium aluminum silicate (commercially available as VEEGUM® in various grades from R. T. Vanderbilt Company); purified sodium magnesium silicate (commercially available as LAPONITE® in various grades); organically modified smectites, including tetraalkyl and / or trialkylammonium smectites (organically modified montmorillonite clays), such as Quaternium-18 bentonite, Quaternium-18 hectorite, stearyl benzyl- dimethyl ammonium bentonite, and stearyl benzyl-dimethyl ammonium hectorite, and mixtures thereof. Magnesium aluminum silicate clays are particularly preferred. One example is VEEGUM® HV.

[0050] Preferably, a 10% aqueous solution of the 2:1 layered silicate clay has a pH of from 8 to 10.

[0051] Preferably, the oral care composition comprises from 0.01 wt% to 5 wt% of the 2:1 layered silicate clay, more preferably from 0.1 to 3 wt%, still more preferably from 0.1 to 2 wt%, most preferably from 0.1 to 1 wt% of the 2:1 layered silicate clay. Oral care compositions comprising from 0.1 wt% to 5 wt% of a 2:1 layered silicate clay are also preferred.

[0052] Xanthan gum According to a first aspect of the present application, the disclosed oral care composition comprises xanthan gum.

[0053] Xanthan gum is a linear (1,4)-linked β-D-glucose backbone (as in cellulose) with a trisaccharide side chain at C-3 on every other glucose. The side chain contains a glucuronic acid residue linked (1,4) to a terminal mannose unit and linked (1,2) to a second mannose linked to the backbone. About 50% of the terminal mannose residues are pyruvoylated and the non-terminal residues typically carry an acetyl group at C-6.

[0054] Xanthan gum typically has a molecular weight of 1 million to 50 million. Preferably, the xanthan gum has a viscosity in the range of 850 to 1,700 mPa-s (when measured at 25°C using a 1 % solution of the gum in 1 % KCl on a Brookfield LV type viscometer using a number 3 spindle at 60 rpm).

[0055] Xanthan gum is available from a number of commercial suppliers such as RT Vanderbilt Company and CP Kelco. Examples of suitable xanthan gums are Keltrol®, Keltrol® F, Keltrol® T, Keltrol® TF, Xantural® 180, and Vanzan® NF.

[0056] Preferably, the xanthan gum derivative can be prepared by etherification, esterification, acetalization, amidation, or oxidation of non-derivatized xanthan gum. Preferred xanthan gum derivatives are prepared by reacting non-derivatized gum with a quaternary ammonium compound in an amount equal to or greater than the stoichiometric amount required for complete derivatization. The quaternary ammonium compound preferably has a single alkyl or alkenyl substituent containing 13 to 24 carbon atoms; and / or two alkyl or alkenyl substituents, each substituent having 12 to 24 carbon atoms. Most preferably, the quaternary ammonium compound is an alkyl dimethyl benzyl ammonium chloride having an alkyl group containing 13 to 24 carbon atoms.

[0057] The disclosed oral care composition comprises 0.1 wt% to 5 wt% xanthan gum. Preferably, the oral care composition comprises at least 0.2 wt%, preferably at least 0.3 wt%, still preferably at least 0.5 wt%, most preferably at least 0.8 wt%, but generally not more than 4.5 wt%, still preferably not more than 3.5 wt%, still further preferably not more than 3.2 wt%, most preferably not more than 3 wt% xanthan gum by weight.

[0058] Other ingredients Fluoride Anti-Caries Compound: The additional ingredient of the composition of the present invention is preferably a fluoride anti-caries compound.

[0059] Examples of such fluoride compounds include sodium fluoride, potassium fluoride, calcium fluoride, magnesium fluoride, stannous fluoride, sodium monofluorophosphate, sodium monofluorophosphate, and copper fluoride. Most preferred is sodium fluoride. These sources should release from about 25 to about 5,000 ppm of fluoride ion. The anti-caries compound will generally be present in an amount of 0.01 wt% to about 5 wt%, preferably 0.1 wt% to 2.5 wt%, optimally 0.2 wt% to 1.5 wt% by weight of the oral care composition.

[0060] Thickening Silica: More preferably, the oral care composition comprises 0 wt% to 15 wt% thickening silica. The primary function of thickening silica is to increase viscosity without increasing the overall abrasive level (RDA) of the formulation. Furthermore, they can be used as a texturing agent in formulations using alternative abrasives besides silica. These physical properties affect the rheological properties of the formulation. For example, and perhaps more relevantly, the higher the oil absorption of the thickener, the higher the viscosity imparted to the formulation. Besides significantly influencing the viscosity of the toothpaste system, thickening silica also plays a role in the mouthfeel of the paste. If the detergent content in the system is low, the formulation may require a less efficient thickener to achieve an overall solids content consistent with the desired mouthfeel.

[0061] This is especially true when the composition contains silica as an abrasive. Various thickening silicas are commercially available. When present, preferred thickening silicas include AEROSIL from Degussa. ® T series or CAB-O-SIL from Cabot Corporation ® Series, silica gels such as SYLODENT from WR Grace & Co. ® Or SYLOX ® Series, or precipitated silica such as ZEOTHIX from JM Huber Corporation ® 265. Available silica thickeners also include ZEODENT. ® 165. ZEODENT ® 163 and / or 167 and ZEOFREE ® 153, 177, and / or 265 silica, all of which are available from JM Huber Corporation. Other preferred thickening silicas include MFIL. ® MFIL ® -P (from Madhu Silica), SIDENT ® 22 S and AEROSIL ® 200 (from Evonik Industries), SYLODENT from WR Grace & Company ® and PERKASIL ® TC 15 PQ thickened silica, and Tixosil from Rhodia ® 43 and 331, synthesized finely divided pyrogenic silica, for example under the trademark SYLOID® 244 SYLOID ® 266 and AEROSIL ® D-200 sold by Grace.

[0062] Zinc salt: The oral care composition of the present application preferably comprises a zinc salt. Preferably, the composition comprises 0.1 to 3 wt% of the zinc salt, more preferably 0.1 to 2 wt%, most preferably at least 0.1 % of the zinc salt.

[0063] Preferably, the zinc compound has a solubility at 20°C of 0.001 to 80 g / 100g water.

[0064] Preferably, the zinc compound is at least one of zinc sulfate, zinc chloride, zinc nitrate, zinc citrate, zinc oxide, zinc lactate, zinc gluconate, zinc glycinate, zinc oleate, zinc hydroxide or zinc peroxide, zinc oxide, zinc lactate, zinc chloride, zinc citrate, zinc acetate, zinc borate, zinc butyrate, zinc carbonate, zinc formate, zinc gluconate, zinc glycerate, zinc glycolate, zinc phosphate, zinc picolinate, zinc propionate, zinc salicylate, zinc silicate, zinc stearate, zinc tartrate, zinc undecylenate, zinc phosphate, zinc ricinoleate or mixtures thereof. Preferably, the zinc salt is selected from zinc chloride, zinc sulfate, zinc nitrate, zinc citrate, zinc gluconate, zinc acetate, zinc lactate, zinc salicylate, zinc gluconate and zinc ascorbate.

[0065] Preferably, the zinc salt is water soluble. This means having a water solubility of greater than 0.01 g / 100g water. For example, the solubility (g / 100g water) of some preferred sparingly water soluble zinc compounds are as follows: zinc citrate 6.11, and zinc lactate 1.4. Water soluble zinc compounds having a solubility at 20°C of greater than 10 g / 100g water include zinc sulfate, zinc chloride and zinc nitrate.

[0066] Preferably, the composition comprises 0.1 wt% to 5 wt% of a zinc salt selected from zinc citrate, zinc gluconate, zinc acetate, zinc lactate, zinc salicylate, zinc gluconate, zinc ascorbate or mixtures thereof.

[0067] Alternatively, the zinc salt comprises a combination of insoluble and soluble zinc salts. Preferably, however, the zinc salt is water soluble.

[0068] Humectant: The oral care composition of the present application preferably comprises from 5wt% to 50wt% of one or more humectants. Alternatively, it is preferred that the oral composition of the present application comprises from 5wt% to 40wt% of humectant. Further preferably, the composition comprises from 10wt% to 40wt% of humectant, more particularly from 10wt% to 20wt% of humectant. A particularly preferred humectant is sorbitol, which is typically available as a 70% aqueous solution.

[0069] Humectants are typically included in toothpastes for a soft, smooth mouth feel. Humectants also reduce the tendency of the toothpaste to lose moisture. Preferably, the humectant is at least one of glycerin, sorbitol, maltitol and xylitol. Sorbitol is available as a 70% aqueous solution. Preferably, the composition comprises glycerin and sorbitol for a lubricious mouth feel, but their cumulative content does not exceed the upper limit disclosed. Lower humectant levels provide an effective way of reducing product cost.

[0070] In one aspect of the present application, alternatively, the composition comprises less than 5wt% of humectant. Preferably, the composition comprises up to 3wt%, more preferably up to 2wt% of humectant. In this case, it is also preferred that the oral care composition is free of humectant. Free of humectant means that the composition comprises no more than 1wt% of humectant, still more preferably 0wt% of humectant, preferably wherein the humectant is sorbitol.

[0071] It is particularly preferred that when the dentifrice composition of the present application comprises less than 5wt% of humectant, the abrasive is a calcium based abrasive. It is particularly preferred that when the dentifrice composition of the present application comprises from 5wt% to 40wt% of humectant, the abrasive is a silica based abrasive.

[0072] Buffering agents: Preferably, the composition of the present application comprises a buffering agent selected from the group consisting of alkali metal silicates, alkali metal hydroxides, alkali metal bicarbonates, alkali metal carbonates, alkali metal pyrophosphates and arginine.

[0073] pH Preferably, the composition of the present application has a pH of from 6.0 to 10.0 at 1wt% of the oral care composition in water, as measured at 25°C, other preferred pH ranges include from 6.5 to 9.5, preferably from 6.5 to 9.0, preferably from 7.0 to 8.0. Most preferably, the composition has a pH range of from 6.5 to 10.

[0074] Surfactants: Oral care compositions, such as dentifrice compositions, and in particular toothpastes, typically comprise a surfactant, often also referred to as a sudsing agent. Suitable surfactants are those which are reasonably stable and provide suds over a wider pH range. Preferably, the composition comprises an anionic surfactant.

[0075] Anionic surfactants useful herein include water-soluble salts of alkyl sulfates having an alkyl group containing 8 to 20 carbon atoms (e.g., sodium alkyl sulfate) and sulfonated monoglycerides of fatty acids having 8 to 20 carbon atoms. Sodium lauryl sulfate and sodium coconut monoglyceride sulfonates are examples of such anionic surfactants.

[0076] Preferably, the composition comprises from 0.25 wt% to 12 wt%, more preferably from 0.5 wt% to 8 wt%, most preferably from 1 wt% to 6 wt% of anionic surfactant.

[0077] Some anionic surfactants, in particular sodium lauryl sulfate, have an antibacterial effect in their own right. This effect provides a degree of immediate antibacterial effect. However, this effect is generally very short-lived. Other surfactants, such as non-ionic, amphoteric or zwitterionic surfactants, can also be included.

[0078] Non-ionic surfactants can be broadly defined as compounds resulting from the condensation of alkylene oxide groups (of a hydrophilic nature) with an organic hydrophobic compound which can be of either aliphatic or alkyl-aromatic nature.

[0079] Examples of suitable non-ionic surfactants include poloxamers (sold under the trade name PLURONIC® ® sold under the trade name TWEEN® ® sold under the trade name POLYOXYL® ® 40 hydrogenated castor oil, fatty alcohol ethoxylates, polyethylene oxide condensates of alkyl phenols, products derived from the reaction of ethylene oxide with the reaction product of propylene oxide and ethylene diamine, ethylene oxide condensates of fatty alcohols, long chain tertiary amine oxides, long chain tertiary phosphine oxides, long chain dialkyl sulfides, and mixtures of such materials.

[0080] Thickening system: Further preferably, the composition of the present application comprises a thickening system comprising thickening silica, and at least one of carboxymethyl cellulose or guar gum. Other binders and thickeners, such as sodium carboxymethyl cellulose, gum arabic can also be included, as well as synthetic polymers, such as polyacrylates and carboxyvinyl polymers, such as Carbopol®.

[0081] Preferred toothpaste compositions can also include one or more other thickening agents, such as carboxyvinyl polymers, which include the carbomers commercially available from B. F. Goodrich as the CARBOPOL® series, including CARBOPOL® 934, 940, 941 and 956.

[0082] Other preferred grades include acrylic acid (ester) / C 10-30 Alkyl acrylate crosspolymers, which are commercially available from Noveon Corporation as ULTREZ® 21, PEMULEN® TR-1 and PEMULEN® TR-2. Preferred compositions can comprise from 0.05 to 10 wt%, more preferably from 0.1 to 5 wt%, even more preferably from 0.25 to about 4 wt% of the other thickening agent.

[0083] Binders: It is preferred that the composition according to the present application comprises a binder, which imparts good structure, in particular for dentifrices in the form of toothpastes. Cellulosic binders are particularly preferred. Preferred cellulosic binders include cellulose ethers, which include hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), ethyl hydroxyethyl cellulose (EHEC), carboxymethyl cellulose (CMC), carboxymethyl hydroxyethyl cellulose (CMHEC), hydroxypropyl hydroxyethyl cellulose (HPHEC), methyl cellulose (MC), methyl hydroxypropyl cellulose (MHPC), methyl hydroxyethyl cellulose (MHEC), carboxymethyl methyl cellulose (CMMC), hydrophobically modified carboxymethyl cellulose (HMCMC), hydrophobically modified hydroxyethyl cellulose (HMHEC), hydrophobically modified hydroxypropyl cellulose (HMHPC), hydrophobically modified ethyl hydroxyethyl cellulose (HMEHEC), hydrophobically modified carboxymethyl hydroxyethyl cellulose (HMCMHEC), hydrophobically modified hydroxypropyl hydroxyethyl cellulose (HMHPHEC), hydrophobically modified methyl cellulose (HMMC), hydrophobically modified methyl hydroxypropyl cellulose (HMMHPC), hydrophobically modified methyl hydroxyethyl cellulose (HMMHEC) and hydrophobically modified carboxymethyl methyl cellulose (HMCMMC).

[0084] Other cellulose binders include cationic hydroxyethyl cellulose (cationic HEC), cationic hydrophobically modified hydroxyethyl cellulose (cationic HMHEC), and microcrystalline cellulose.

[0085] A highly preferred binder is sodium carboxymethyl cellulose (SCMC). Particularly preferred sodium carboxymethyl celluloses include those having a degree of substitution of 0.6 to 0.99, preferably 0.7 to 0.95.

[0086] The dentifrice compositions of the present application can include other ingredients optionally present, such as cosmetically acceptable carriers, such as starch and sucrose.

[0087] Alkali metal silicate: The dentifrice composition preferably includes an alkali metal silicate. The alkali metal is sodium or potassium, preferably sodium. Sodium silicate is generally available as a 10 to 40% aqueous solution, most commonly a 30% solution. Sodium silicate is available as neutral sodium silicate or as alkaline sodium silicate. Preferred toothpastes have neutral sodium silicate. Sodium silicate is available in different Na2O:SiO2ratios.

[0088] Preferred is sodium silicate having a Na2O:SiO2ratio in the range of 3.0 to 3.8, more highly preferred ranges are 0.2 to 3, also preferred is the range of 1.2 to 3 and the range of 1.2 to 1.5. Preferred toothpastes include 0.1 wt% to 5 wt% silicate (based on dry weight), also preferred is the range of 0.2 wt% to 3 wt%, still preferred is 1.2 wt% to 1.5 wt%. Thus, a 30% sodium silicate solution is added to the composition in an amount in the range of 0.3 wt% to 16 wt%.

[0089] Flavorant: Flavorants, such as peppermint and spearmint oils, and preservatives, coloring agents, pH adjusting agents, sweeteners, and the like can also be included. Suitable flavoring components include wintergreen oil, peppermint oil, spearmint oil, clove bud oil, menthol, anethole, methyl salicylate, eucalyptol, cascarilla, 1-menthyl acetate, sage, eugenol, parsley oil, oxanone, alpha-irisone, thyme, lemon, orange, propenyl guaethol, cinnamon, vanillin, ethyl vanillin, heliotropine, 4-cis-heptenal, diacetyl, p-tertiary butyl phenyl acetate, and mixtures thereof. Coolants can also be part of the flavor system. Preferred coolants are the paramenthan carboxyamide class of agents, such as N-ethyl-p-menthan-3-carboxamide (commercially known as "WS-3 ® ") and mixtures thereof. The flavorant is typically 0.001 to 5 wt%.

[0090] Anticaries agents: Anticaries agents such as sodium and stannous fluoride, amine fluorides, monosodium fluorophosphate, casein, plaque buffers such as urea, pyruvate, arginine, small peptides, calcium lactate, calcium glycerophosphate, strontium polyacrylate can also be included. The preferred anticaries agent is monosodium fluorophosphate. Other optional ingredients include vitamins such as vitamin C, and plant extracts. Desensitizing agents such as potassium bicarbonate, potassium oxalate, potassium nitrate, and strontium salts can also be included.

[0091] Buffering agents: Salts and buffers for buffering the pH and ionic strength of the composition can also be included. Liposomes and other encapsulations can also be used to improve delivery or stability of the active ingredients.

[0092] Anticalculus agents: In addition, the oral care composition can comprise an anticalculus agent such as alkali metal pyrophosphates, hypophosphite-containing polymers, organic phosphonates and phosphocitrates.

[0093] Organic polyphosphates: The dentifrice composition of the present application can comprise an organic polyphosphate or a water-soluble salt thereof, said polyphosphate or said salt having an average chain length of at least 4. Preferably, the composition comprises from 0.01 to 5 wt% of the organic polyphosphate, more preferably from 0.05 to 4 wt%, further preferably from 0.15 to 3 wt%, most preferably from 0.15 to 2 wt% of the organic polyphosphate. Preferably, the organic polyphosphate is phytic acid. In this case, it is in the form of the acid. Phytic acid, also known as myo-inositol hexaphosphate or inositol hexaphosphoric acid, is a biodegradable chelating agent, in liquid form, with chelating properties comparable to EDTA. In this context, the term "phytic acid" includes phytic acid and its salts as well as other polyphosphorylated inositol compounds.

[0094] When the organic polyphosphate is in the form of a water-soluble salt, it is preferably an alkali metal salt or an alkaline earth metal salt. Preferably, the salt is at least one of sodium phytate, potassium phytate, magnesium phytate, calcium phytate, stannous phytate, zinc phytate, copper phytate or iron phytate.

[0095] Inorganic polyphosphates: The dentifrice composition of the present invention can also comprise an inorganic polyphosphate or a water-soluble salt thereof, having an average chain length of at least 4. Preferably, the composition comprises from 0.1 to 5 wt% of the inorganic polyphosphate, more preferably from 0.5 to 4 wt%, further preferably from 0.5 to 3 wt%, most preferably from 0.5 to 2 wt% of the inorganic polyphosphate.

[0096] The inorganic polyphosphates useful in embodiments of the oral care formulations disclosed herein can consist of a plurality of phosphate molecules arranged in linear and / or cyclic configurations. Polyphosphates are generally understood to consist of two or more phosphate molecules arranged primarily in linear configurations, although some cyclic derivatives can exist. While pyrophosphate (n = 2) is technically a polyphosphate, the polyphosphates of interest are those having at least 4 phosphate groups. In one embodiment, such polyphosphates are prepared by mixing linear and cyclic polyphosphates in sufficient concentrations to achieve a specific average chain length of at least 4. The inorganic polyphosphates can also have branched forms.

[0097] Preferably, the inorganic polyphosphate is a pyrophosphate, a trimetaphosphate, a tripolyphosphate, or an ultrametaphosphate. The inorganic polyphosphate can exist as a mixture of linear and cyclic polyphosphates, primarily comprising cyclic combinations of polyphosphate compounds, or "cyclic / cyclic combination polyphosphate mixtures", or linear combinations of polyphosphate compounds, or "cyclic / linear combination polyphosphate mixtures", such as tetraphosphate 4 and hexametaphosphate 6. Polyphosphates greater than tetraphosphate typically exist as amorphous glassy materials. Preferred in the present invention are linear polyphosphates having the general formula: XO(XPO3)nX, where X is sodium, potassium, or ammonium, and n averages from 4 to 125. Preferred polyphosphates are those in which n averages from about 6 to about 21, such as those commercially known as Sodaphos (n = 6), Hexaphos (n = 13), and Glass H (n = 21).

[0098] It is particularly preferred that the inorganic polyphosphate is a hexametaphosphate. More particularly it is sodium hexametaphosphate. It has the following structure: The inorganic polyphosphate or water-soluble salt thereof is different from monofluorophosphate or tripolyphosphate.

[0099] The weight ratio of the organic phosphate to the inorganic phosphate is from 1 : 10 to 1 : 0.05, more preferably from 1 : 7 to 1 : 0.1.

[0100] Preservatives: Toothpastes with calcium-containing abrasives, in particular chalk, are prone to bacterial growth. Specific preservatives, such as methyl, ethyl, butyl, propyl and isopropyl esters of p-hydroxybenzoic acid, can be particularly useful against bacterial growth. Mixtures of methyl, ethyl, butyl and propyl esters of p-hydroxybenzoic acid are particularly preferred.

[0101] The activity of the mixture can be enhanced by the addition of phenoxyethanol. Formaldehyde and dimethylhydantoin are other preferred preservatives. Preservatives are typically included in amounts of 0.005 to 0.8 wt%.

[0102] Antibacterial agents: The oral care composition can preferably comprise an antibacterial agent, such as triclosan, chlorhexidine, sanguinarine extract, metronidazole. Other examples of antibacterial agents are quaternary ammonium compounds, such as cetylpyridinium chloride; bisguanides, such as chlorhexidine digluconate, hexetidine, octenidine, alexidine; halogenated bisphenolic compounds, such as 2,2'methylenebis-4(4-chloro-6-bromophenol).

[0103] Polymeric compounds which can enhance the delivery of active ingredients, such as antibacterial agents, can also be included.

[0104] Other optional ingredients: Other optional ingredients which can be included are, for example, bleaching agents, such as peroxide compounds, such as potassium peroxodiphosphate; foaming systems, such as sodium bicarbonate / citric acid systems; and colour change systems.

[0105] The composition of the present application can also contain coloured particles suspended therein, for example, coloured silica agglomerates or other coloured particles, to impart a "speckled" appearance to the dentifrice. The oral care composition can also contain a band of coloured paste to provide a visually distinct gel dentifrice having a coloured band or separate coloured phase.

[0106] Packaged product According to another aspect, disclosed is a packaged product comprising an oral care composition, preferably a dentifrice composition, more preferably a toothpaste composition of the present application. The gel composition is preferably packaged in a collapsible tube, so that small amounts are easily dispensed without too much skill. Alternatively, the composition is packaged in another type of container, such as a bottle or jar, preferably with suitable means for dispensing a known amount of the composition. The package can further be packaged in a suitable secondary package, such as a carton or box, preferably with available information about the contents and instructions for use. Typically, the oral care composition is packaged.

[0107] In toothpaste or gel form, the composition can be packaged in a conventional plastic laminate, metal tube or single-compartment dispenser. It can be applied to the tooth surface by any physical means, for example by toothbrush, fingertip or directly to sensitive areas by an applicator.

[0108] Method of use The composition can be effective even when used in the individual's daily oral hygiene routine. For example, the composition can be brushed onto the teeth. For example, the composition can be in contact with the teeth for 1 second to 20 hours. More preferably 1 second to 10 hours, still more preferably 10 seconds to 1 hour, most preferably 30 seconds to 5 minutes. The composition can be used daily, for example by the individual once, twice or three times a day. When the oral care composition is a biphasic composition, the two phases of the composition are mixed during application. Typically, the mixed phases are left on the teeth for 3 minutes to 10 hours, more preferably 3 minutes to 8 hours. One to five applications can be made per month.

[0109] Therapeutic treatment can be summarised as a measure for the maintenance (prevention) or restoration (treatment) of health. "Treatment" involves returning the body from a pathological state to its normal, healthy state and involves preventing a pathological state. Treatment by therapy is defined as any treatment intended to cure, alleviate, remove or lessen the symptoms of any disease or malfunction of the human or animal body, or to prevent or reduce the likelihood of contracting any disease or malfunction of the human or animal body.

[0110] According to a second aspect of the present application, there is disclosed a composition according to the first aspect for use in promoting remineralisation of teeth.

[0111] According to a third aspect of the present application, there is disclosed the use of 0.1 wt% to 5 wt% xanthan gum, 1 : 1 layered silicate clay, 2: 1 layered silicate clay in an oral care composition comprising an abrasive selected from a calcium based abrasive, a silica based abrasive or a mixture thereof for use in promoting remineralisation of teeth.

[0112] Examples The present application will now be explained in detail by means of the following non-limiting exemplary examples.

[0113] A series of toothpaste compositions were formulated by following standard procedures. Test-3 and Test-6 are within the scope of the present application. Two non-fluoridated compositions (Test-7, Test-8) were also prepared for comparative evaluation.

[0114] Table 1

[0115] All of the compositions of Table 1 were subjected to various standard tests to determine which compositions had any beneficial effect on the uptake of fluoride by tooth enamel. In addition, the compositions were subjected to various tests to determine and compare their effects on remineralization and demineralization.

[0116] The test methods are summarized below, and the observations are listed in Table 2, followed by inferences drawn from the data.

[0117] Surface microhardness test Tooth Enamel Sample Preparation: Test tooth enamel samples from human permanent teeth were used as the hard tissue test substrate. The teeth were sorted and cleaned. The selection of teeth for further processing was based on the quality of the enamel and whether the particular tooth surface had sufficient size to obtain a sample of sufficient size to meet the study requirements. Teeth sections with white spots, cracks, and other defects were discarded. The teeth sections were cut into 3 millimeter x 3 millimeter samples using a low speed saw. The teeth were stored in thymol during the sample preparation process. The 3 x 3 millimeter samples were ground and polished to create a flat surface to facilitate surface microhardness testing by using a polishing unit. The bottom surface of the samples was ground to a uniform thickness with 500-grit silicon carbide grinding paper. The top surface of the samples was ground using 1200-grit paper until most of the tooth surface was flattened. The samples were successively polished using 4000-grit paper and then by a 1 micron diamond polishing suspension. The samples had at least 0.3 millimeter of enamel thickness. Between each grinding / polishing step, the samples were sonicated in deionized water. As a final cleaning step, the polished samples were sonicated in 2% Micro- Liquid. The samples were evaluated at 10X magnification. To be accepted for the study, the samples needed to meet the following: a) No apparent cracks or other defects in the enamel surface; b) A uniform, polished, high-gloss enamel surface; c) No contamination on the top surface from sticky wax or any other material.

[0118] Each sample was mounted on an acrylic plate using wax. The sides of each sample were coated with varnish so that only the enamel surface was exposed. On the enamel surface, a reference area of approximately 3 millimeter x 1 millimeter was created on each sample using acid-resistant, clear nail polish. Eight samples per group were used for each test.

[0119] Lesion Preparation: 1. Methylcellulose system The labial surface of a human tooth was ground to yield an area of approximately 4 mm width (mesiodistally). The ground area was polished on a glass plate with 1200 grade alumina slurry. A section of approximately 3.5 x 3.5 mm size was cut from the polished area, through the width of the tooth. The sides of the section were coated with acid resistant nail polish and the polished area was coated leaving a window of approximately 3 mm x 3 mm. The enamel section was mounted in dental wax at the bottom of a crystallizing dish with the polished face facing upwards.

[0120] A 500 ml quantity of deionized water was brought to a boil and about 460 ml was weighed into a beaker, stirring, with a thermometer in the water. 40 grams of methylcellulose (high degree of substitution) was weighed. When the water had cooled to about 80°C, the methylcellulose was added, continuing to stir. When the suspension had cooled to about 50°C, it was poured over the enamel section to a depth of about 2.5 cm (the temperature at which the mixture is poured varies depending on the temperature at which the grade of methylcellulose "sets"). The dish was covered and refrigerated at 4°C for 2 / 3 hours until clear. Care was taken that the enamel window was not covered by any air bubbles, as this would delay lesion formation.

[0121] 2. Lactic acid system 0.1 molar, pH 4.6 9 g ± 1% lactic acid (if 100% pure) (our lactic acid is 88% pure, so to get 9 g of lactic acid, 9 x (100 / 88) or 10.23 g is required) was weighed into 100 ml of deionized water in a small conical flask and gently boiled on a hot plate with stirring for 1 hour. A small watch glass was placed over the beaker to prevent the acid from boiling away. (The lactic acid forms anhydride in concentrated form and the boiling hydrolyzes it.) The acid was allowed to cool and brought to a total volume of about 970 ml in the beaker, adjusting the pH to 4.6 ± 0.02 with saturated KOH while stirring. The acid was added to a 1 liter volumetric flask and brought to the mark with deionized water. The methylcellulose was covered with a piece of filter paper and 2.5 cm of lactic acid was added. Incubate at 37°C for 8 days, after which the acid / gel system was removed, the tooth was rinsed with copious amounts of deionized water and stored dry until needed.

[0122] Treatment with toothpaste The samples were mounted in dental wax at the bottom of a crystallizing dish with the lesion facing upwards for treatment with the product. This included: • Immersion in 1 :3 toothpaste: for paste formulation, the water slurry was left overnight at 37°C with periodic stirring.

[0123] After treatment, the samples were rinsed thoroughly in deionized water.

[0124] Acid erosion The lesion samples were mounted in dental wax on glass microscope slides. An aliquot of 50 microliters of 1 molar perchloric acid was pipetted onto each lesion and allowed to sit for 10 minutes. Subsequently, the acid was drawn from the lesion into a separate pre-weighed vial under vacuum. Each lesion was then rinsed with three 50 microliter aliquots of 1 molar sodium acetate, which were combined with the acid in the vial using the same vacuum technique.

[0125] Analysis of fluoride The fluoride activity of the etching solution from each lesion was determined using a pH meter connected to a combination fluoride ion selective electrode, which is suitable for analysis of small volumes. A calibration curve was calculated (by linear regression analysis) prior to fluoride measurements using daily prepared fluoride standard solutions. At the end of the experiment, all freshly made solutions were discarded.

[0126] Example 2: Determination of remineralization and demineralization The toothpaste composition as provided in Table 2 is: Re-mineralization The tooth samples were first immersed in the toothpaste slurry for five minutes. The toothpaste slurry was prepared by mixing one part of the toothpaste composition with three parts of deionized water with 10 UI / mL alkaline phosphatase.

[0127] The tooth samples were then immersed in the acidic buffer for one hour. The acidic buffer was prepared by mixing 50 millimolar acetic acid and 1.5 millimolar KH2PO4; pH 5.0.

[0128] Thereafter, the tooth samples were immersed in the neutral buffer for one minute. The neutral buffer was prepared by mixing 20 millimolar HEPES and 1.5 millimolar KH2PO4; pH 7. The cycle was repeated 6 times per day for 2 days. During the night, the enamel slabs were stored in the neutral buffer solution. Note: the acidic buffer was reserved for analysis.

[0129] The tooth samples were rinsed after each step to thoroughly rinse off the active agents from the previous step.

[0130] The degree of remineralization was evaluated by microhardness analysis of the enamel blocks before and after the pH cycle. Four readings were taken for each sample, and the level of remineralization was expressed as percent recovery of hardness Vickers (Hardness Vickers = HV) as follows: Percent recovery of HV = (Δ HV / HV baseline) 100 where Δ HV is calculated as follows: Average HV after treatment - Average HV before treatment.

[0131] In the present study, the foregoing toothpaste formulations were tested using a design of experiments matrix, ensuring random allocation of the test toothpaste formulations.

[0132] Demineralization First, the tooth sample was immersed in a toothpaste slurry for five minutes. The toothpaste slurry was prepared by mixing one part of the toothpaste composition with three parts of deionized water containing 10 UI / mL of alkaline phosphatase.

[0133] Next, the tooth sample was immersed in an acidic buffer for one hour. The acidic buffer was prepared by mixing 50 millimoles / L of acetic acid and 1.5 millimoles / L of KH2PO4; pH 5.0.

[0134] Thereafter, the tooth sample was immersed in a neutral buffer for one minute. The neutral buffer was prepared by mixing 20 millimoles / L of HEPES and 1.5 millimoles / L of KH2PO4; pH 7. The cycle was repeated 6 times per day for 2 days. During the night, the enamel slabs were stored in the neutral buffer solution. Note: the acidic buffer was reserved for analysis.

[0135] The tooth sample was rinsed after each step to thoroughly rinse off the active agent from the previous step. Efficacy was evaluated by microhardness analysis of the tooth sample before and after the pH cycle.

[0136] Four readings were taken for each tooth sample, and demineralization was expressed as a percentage decrease in hardness.

[0137] Efficacy was evaluated by microhardness analysis of the enamel blocks before and after the pH cycle. Four readings were taken for each sample, and demineralization was expressed as a percentage decrease in Vickers hardness (HV decrease %) as follows: Percentage decrease in HV = (Average HV after treatment - Average HV before treatment / Average HV before treatment) X 100 Table 2

[0138] The data provided in Table 2 indicates that when the composition has a combination of 1 : 1 layered silicate clay (kaolin), 2: 1 layered silicate clay (Veegum® HV), and xanthan gum (Test-3, Test-6), it provides improved remineralization and reduces demineralization.

Claims

1. An oral care composition comprising: (i) A friction agent selected from calcium-based friction agents, silica-based friction agents, or mixtures thereof; (ii) 1:1 layered silicate clay; and, (iii) 2:1 layered silicate clay; The composition contains 0.1 wt% to 5 wt% xanthan gum.

2. The composition according to claim 1, wherein the 1:1 layered silicate is kaolinite.

3. The composition according to claim 2, wherein the kaolinite is selected from kaolin, halloysite, pearl clay and dickite.

4. The composition according to any one of claims 1 to 3, wherein the 2:1 layered silicate is montmorillonite clay.

5. The composition according to claim 4, wherein the montmorillonite clay is selected from succinate, montmorillonite, bentonite, hydropyrite, sodium magnesium silicate, magnesium aluminum silicate, organically modified montmorillonite, and organically modified montmorillonite clay.

6. The composition according to claim 5, wherein the montmorillonite clay is magnesium aluminum silicate clay.

7. The composition according to any one of the preceding claims, wherein the composition comprises 10 wt% to 70 wt% of a wetting agent.

8. The composition according to claim 7, wherein the wetting agent is selected from glycerin, sorbitol, xylitol, butylene glycol, propylene glycol and mixtures thereof.

9. The composition according to any one of the preceding claims, wherein the 1:1 layered silicate clay is present in the composition in an amount ranging from 0.1 wt% to 5 wt%.

10. The composition according to any one of the preceding claims, wherein the 2:1 layered silicate clay is present in the composition in an amount ranging from 0.1 wt% to 5 wt%.

11. The composition according to any one of the preceding claims, wherein the amount of the friction agent in the composition ranges from 10 wt% to 50 wt%.

12. The composition according to any one of the preceding claims, wherein the composition comprises a buffer selected from alkali metal silicates, alkali metal hydroxides, alkali metal bicarbonates, alkali metal carbonates, alkali metal pyrophosphates, arginine, and combinations thereof.

13. The composition according to any one of the preceding claims, wherein the pH of the composition is from 6.0 to 10.

0.

14. The composition according to any one of the preceding claims, wherein the composition is used to promote tooth remineralization.

15. Use of 0.1 wt% to 5 wt% xanthan gum, 1:1 layered silicate clay, 2:1 layered silicate clay in an oral care composition for promoting tooth remineralization, the oral care composition comprising an abrasive selected from calcium-based abrasives, silica-based abrasives, or mixtures thereof.

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