Oral care composition

Abstract

The present invention relates an oral care composition. There is need for oral care composition that provides remineralization and at the same time, prevents or at least reduces demineralization. The present inventors have observed that a combination of a 1:1 layered silicate clay, a 2:1 layered silicate clay and xanthan gum is synergistic and together they remineralize the teeth and preferably reduce their demineralization.

Description

[0001] ORAL CARE COMPOSITION

[0002] Field of the Invention

[0003] The present invention relates an oral care composition. The invention particularly relates to a composition for remineralization.

[0004] Background of the Invention

[0005] Abrasives used in oral care compositions such as dentifrices need to be effective in removing extrinsic stains, dental plaque and food debris which builds up on the pellicle on the surface of teeth.

[0006] In general, the efficiency of physical removal of stain, plaque and food debris can be increased by using an abrasive having increased abrasivity, or by increasing the amount of abrasive incorporated into the composition. However, both these approaches also increase the risk that tooth surfaces may be damaged.

[0007] The primary component of the enamel and dentin in teeth is calcium phosphate in the form of hydroxyapatite.

[0008] In the mouth, there is a natural equilibrium between hydroxyapatite being dissolved from the enamel of teeth and hydroxyapatite being formed on or in the teeth from substances occurring naturally in the saliva. This equilibrium is shifting continuously. Among other factors, it is determined by diet and physical condition.

[0009] If the equilibrium is such that hydroxyapatite is being dissolved, a cariogenic condition arises which is referred to as demineralization. Exposure of the dental hard tissues to acid causes demineralization, resulting in surface softening and a decrease in mineral density. Dental erosion (i.e., acid erosion or acid wear) is a surface phenomenon that involves demineralization, and ultimately complete dissolution of the tooth surface by acids that are not of bacterial origin. Most commonly the acid will be of dietary origin. Due to today's lifestyle which involves increasing consumption of acidic drinks and foods, tooth erosion is becoming more prevalent and common.

[0010] If the equilibrium is such that hydroxyapatite is being formed, this is referred to as remineralization. Remineralization hardens and strengthens the teeth, thereby providing protection from and treatment for dental erosion and / or tooth wear. It also reduces the likelihood of tooth decay and improves the appearance of the teeth, in particular their whiteness. The teeth may also appear smoother and shinier as a result.

[0011] The presence of fluoride ions can enhance the natural remineralization process, and this is one of the accepted mechanisms by which fluoride toothpaste and rinses protect against caries. Fluoride is most effective during the developmental years from childhood to young adulthood.

[0012] However, the ability of fluoride to promote remineralization can be limited by the availability of calcium and phosphate ions in saliva.

[0013] W02014170096 A1 (Unilever) discloses a toothpaste composition comprising calcium-based abrasive; humectant and up to 2 wt.% thickening silica, wherein the composition comprises 0.2 wt.% to 3 wt.% smectite clay. The composition provides superior sensory profile as well as an increased uptake of antibacterial agent by the oral tissues.

[0014] W02013007571 A2 (Unilever) discloses toothpaste containing balanced amounts of calcium- based abrasive, copolymer of vinyl methyl ether and maleic acid and clay are stable even at elevated temperatures. The composition may 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 :0075 and ratio of said calcium-based abrasive to said clay is at least 1:0.02.

[0015] WO2020212361 A1 (Unilever) discloses non-aqueous toothpaste comprising polysaccharide, especially xanthan gum, and calcium carbonate to decrease relative dentin abrasivity (RDA) without reducing cleaning efficiency (PCR).

[0016] There is need for oral care composition that provide remineralization and at the same time, prevents or at least reduce demineralization.

[0017] Summary of the Invention

[0018] The present inventors have observed that a combination of a 1:1 layered silicate clay, a 2:1 layered silicate clay and xanthan gum is synergistic and together they remineralize the teeth and reduce their demineralization.

[0019] According to a first aspect of the present invention disclosed is an oral care composition comprising: i. abrasive selected from calcium-based abrasive, silica-based abrasive or mixtures thereof; ii. 0.1 wt.% to 5 wt.% 1 :1 layered silicate clay; and, iii. 0.1 wt.% to 5 wt.% 2:1 layered silicate clay; wherein the composition comprises 0.1 wt.% to 5 wt.% xanthan gum.

[0020] According to a second aspect of the present invention disclosed is a composition according to the first aspect for promoting remineralization of teeth.

[0021] According to a third aspect of the present invention disclosed is 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 having abrasive selected from calcium-based abrasive, silica-based abrasive or mixtures thereof for promoting remineralization of teeth.

[0022] According to the invention the term “remineralization” refers to the in-situ generation of hydroxyapatite on teeth.

[0023] Detailed Description of the Invention

[0024] According to a first aspect of the present invention disclosed is an oral care composition which includes an abrasive, 1 :1 layered silicate clay, 2:1 layered silicate clay and xanthan gum.

[0025] Oral care composition

[0026] Disclosed oral care composition may take any product form suitable for application to the surface of the teeth preferably in a mixture with water. Examples of such product forms include solid forms, such as powders or discrete unit doses (for example pellets, pastilles, tablets and the like).

[0027] Preferably the composition is in the form of a dentifrice. The term "dentifrice" denotes an oral composition which is used to clean the surfaces of the oral cavity. Such a composition is not intentionally swallowed for purposes of systemic administration of therapeutic agents, but is applied to the oral cavity, used to treat the oral cavity and then expectorated. Typically, such a composition is used in conjunction with a cleaning implement such as a toothbrush, usually by applying it to the bristles of the toothbrush and then brushing the accessible surfaces of the oral cavity. A dentifrice for use in the invention is suitably in the form of an extrudable semi-solid such as a cream, paste or gel (or mixture thereof). In one aspect of the invention, the oral care composition is a dentifrice composition, more preferably a toothpaste.

[0028] Alternatively, the composition of the invention preferably comprises a first and a second dentifrice composition, where the first composition comprises a silica-based abrasive and the second composition comprises a calcium-based abrasive. The two types of compositions may preferably be presented in the form of a multiphase composition, such as core-&-sheath type or a side-by-side form. Alternatively, the compositions may be provided in the aforesaid forms by way of packaging solutions, such as core-&-sheath type.

[0029] Alternatively, a kit may be supplied to the consumer in which the anhydrous oral care composition as described above is packaged together with an independent aqueous activator. The viscosity of the dentifrice generally ranges from 10,000 to 100,000 cps, and preferably ranges from 30,000 to 60,000 cps, (when measured at 25°C on a Brookfield viscometer).

[0030] Preferably the pH of the oral care composition at when measured using a 1wt.% aqueous solution of the oral care composition in distilled water and as measured at 25°C using conventional pH sensitive electrodes is from 6.0 to 10.0, preferably from 6.5 to 9.5, more preferably 6.5 to 9.0, even more preferably from 7.0 to 8.0.

[0031] A composition, in particular dentifrice for use in the invention will also generally contain further ingredients to enhance performance and / or consumer acceptability.

[0032] Abrasive

[0033] According to a first aspect of the present invention disclosed is an oral care composition which includes an abrasive. According to the first aspect the abrasive is selected from a calcium- based abrasive, silica-based abrasive, or mixtures thereof.

[0034] Disclosed oral care composition includes from 3 wt.% to 75 wt.% 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 metaphosphate, sodium and potassium pyrophosphates, sodium trimetaphosphate, sodium hexametaphosphate, particulate hydroxyapatite and mixtures thereof. In one aspect of the invention the abrasive is silica-based abrasive. When the dentifrice composition of the invention is a gel toothpaste, it preferably comprises 3 wt.% to 20 wt.% silica, more preferably 4 wt.% to 15 wt.% and most preferably 4 wt.% to 10 wt.%.

[0035] Such toothpastes are usually transparent or translucent gels. The term gel indicates physical appearance of the compositions. The gel compositions are transparent to light, i.e., they allow visible light to pass through. Clear gel toothpastes are popular with consumers.

[0036] When the oral care composition of the invention is a toothpaste in the form of a gel, it is preferred that the compositions do not comprise more than 5 wt.%, preferably more than 2 wt.% and more preferably more than 1 wt.% calcium-based abrasive. It could affect the transparent nature of the compositions.

[0037] Further preferably the abrasive silica comprises medium- and high-abrasive silica, where medium-abrasive silica is preferably in majority. Their relative proportions may vary. Preferably the abrasive silica is low refractive index silica with an apparent refractive index in the range of 1.41 to 1.47, preferably 1.435 to 1.445, preferably having a weight mean particle size of between 5 and 15 pm, a BET (nitrogen) surface area of between 10 and 100 m2 / g and an oil absorption of about 70 to 150 cm3 / 100 g. Examples of suitable low refractive index abrasive silicas having an R.l. of between 1.435 and 1.445 are Tixosil 63 and 73 ex Rhone Poulenc; Sident 10 ex Degussa; Zeodent 113 ex Zeofinn; Sorbosil AC 77 ex Ineos having an R.l. of approximately 1.440. Other examples include the Sylodent® and Syloblanc® range of abrasive silicas from Grace.

[0038] Preferably, the abrasive silica is precipitated silica. Suitable precipitated silicas for use as abrasive amorphous silica particles in the invention are commercially available and include those marketed by PQ Corporation under the trade names SORBOSIL® AC 43, AC77, AC35 and SORBOSIL® AC 33. Mixtures of any of the materials may also be used. Preferably the toothpaste composition comprises 1 wt.% to 10 wt.% abrasive silica. Examples of abrasives include abrasive amorphous silica particles which have a weight mean particle size (d50) ranging from 3 to 15 microns. Preferred abrasive amorphous silica particles for use in the composition of the invention have a weight mean particle size in the range 3 to 6 microns. Preferably, the abrasive amorphous silica particles employed are precipitated silica.

[0039] Preferably when the abrasive is a silica-based abrasive the oral care composition includes at least 1 wt.%, preferably at least 2 wt.%, still preferably at least 2.5 wt.% and most preferably at least 4 wt.%, but typically not more than 10 wt.%, still preferably not more than 9 wt.%, still further preferably not more than 8 wt.%, and most preferably not more than 7 wt.% by weight of the silica-based abrasive.

[0040] On the other hand, there are some other types of dentifrice compositions of the toothpaste type that are not gels but are opaque. That is because such compositions usually contain opacifying ingredients such as chalk or other calcium-based abrasives.

[0041] Alternatively, the dentifrice compositions of the invention comprise calcium-based abrasive. When the dentifrice composition of the invention comprises a calcium-based abrasive, it preferably comprises 10 wt.% to 50 wt.% abrasive, more preferably 10 wt.% to 45 wt.%, further preferably 20 wt.% to 40 wt.% calcium-based abrasive.

[0042] A particularly preferred calcium-based abrasive is fine ground natural chalk (FGNC). It is obtained from limestone or marble. FGNC may also be modified chemically or physically by coating during or after milling by heat treatment. Typical coating materials include magnesium stearate and oleate. The morphology of FGNC may also be modified during the milling process by using different milling techniques, for example, ball milling, air-classifier milling or spiral jet milling. FGNC can be used as the sole calcium containing abrasive. However, FGNC can also be used with other calcium containing abrasives to balance the abrasion. 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 is 35 to 100 %, more preferably 75 to 100 % and especially from 95 to 100 % of the total abrasive. In such cases, the balance, most preferably, is PCC.

[0043] 1 :1 Layered silicate clay

[0044] According to a first aspect of the present invention disclosed is an oral care composition which includes a 1 :1 layered silicate clay.

[0045] Preferably the 1 :1 layered silicate is a kaolinite. It is preferred that the kaolinite is selected from the group consisting of kaolin, halloysite, nacrite and dickite. More preferably it is kaolin. Kaolinites have a dioctahedral sheet and the species included within the kaolinites subgroup are kaolinite, dickite, nacrite and halloysite clay minerals, but not limited thereto. Serpentines are trioctahedral sheet minerals which has a tetrahedral sheet and an octahedral sheet having magnesium with minor amounts of aluminium and the species within this subgroup are preferably chrysotile, lizardite and antigorite. Kaolin (also known as kaolinite) is a naturally occurring mineral. Preferred kaolin is a hydrous aluminium silicate and represented as AhCh^SiCh^FW. Preferred kaolinites have particle size distribution such that at least 98 wt% of the particles have a particle size of 2 pm or less. It is preferred that the 1 :1 layered silicate clay is of the non-swelling type.

[0046] Kaolinites have a dioctahedral sheet and the species included within the kaolinites subgroup are kaolinite, dickite, nacrite and halloysite clay minerals, but not limited thereto. Kaolinite is particularly preferred in the disclosed invention. Kaolinite, commonly known as kaolin clay, is a naturally occurring mineral. Kaolinite may be a calcined kaolin, highly purified calcined kaolin, colloidal kaolin, or hydrated kaolin, but not limited thereto. Preferred kaolinite is a hydrous aluminium silicate and represented as AhCh^SiCh^FW. Preferred kaolinite have particle size distribution such that at least 98 wt% of the particles have a particle size of 2 pm or less. Preferably the kaolinite is a refined kaolin and further preferably the refined kaolin includes 38 wt% AI2O3 and 45wt% SiC>2 and a maximum of 0.5 wt% of Fe2C>3.

[0047] The oral care composition includes 0.01 wt.% to 5 wt.% 1 :1 layered silicate clay, more preferably 0.1 wt.% to 5 wt.% 1 :1 layered silicate clay. It is preferred that the dentifrice composition comprises 0.01 wt.% to 5 wt.% of said 1:1 layered silicate clay, more preferably 0.1 wt.% to 3 wt.% and still more preferably 0.1 wt.% to 2 wt.% and most preferably 0.1 wt.% to 1 wt.%.

[0048] 2:1 Layered silicate clay

[0049] According to a first aspect of the present invention disclosed is an oral care composition which includes a 2:1 layered silicate clay.

[0050] The oral care composition according to the present invention comprises a 2:1 layered silicate clay. It is preferred that 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 silicates, aluminium magnesium silicate, organically modified smectites and organically modified montmorillonite clay. The pyrophillite-talc group preferably includes talc which is a hydrous magnesium silicate; pyrophyllite which is a hydrous aluminium silicate; or minnesotaite which is a hydrous iron silicate. The vermiculite group of clay preferably includes the dioctahedral vermiculite or the trioctahedral vermiculite. The trioctahedral vermiculites preferably has a layer charge of 0.6 to 0.7. It is highly preferred that the 2:1 layered silicate clay is of the smectite group of clay which includes but not limited to montmorillonite, smectite, beidellite, nontronite saponite, hectorite, sauconite or laponite. The smectite group of clay is preferably dioctahedral smectites or trioctahedral smectites.

[0051] Examples of suitable dioctahedral smectites include, but are not limited to, montmorillonite (often referred to as bentonite), smectite, beidellite, nontronite.

[0052] Typically, montmorillonite and smectite have a low total charge content of from 0.3 to 0.6 and most of the charge originates in the octahedral sheet. Beidellite is an expandable dioctahedral smectite having a total charge content of 0.7 or higher and a tetrahedral charge content of 0.4. When the dioctahedral smectites is a montmorillonite, it is typically carbonate free and preferably water washed.

[0053] Examples of suitable trioctahedral smectites include, but are not limited to, saponite, hectorite, sauconite, and laponite. Trioctahedral smectites having a total charge content of 0.3 to 0.5 includes hectorite which has magnesium and lithium in the octahedral sheet and saponite which has considerable magnesium in the octahedral sheet and some aluminium substitution in the tetrahedral sheet.

[0054] A particularly preferred 2:1 layered clay is a smectite group of clay which may be from a natural source, processed or purified from a natural source or prepared synthetically. More preferably the 2:1 layered silicate clay is a magnesium aluminium silicate (various grades are commercially available as VEEGLIM® from R. T. Vanderbilt Company); purified sodium magnesium silicates (commercially available as LAPONITE® in various grades); organically modified smectites including tetra alkyl and / or trialkyl ammonium smectites (organically modified montmorillonite clays) such as quaternium-18 bentonite, quaternium-18 hectorite, stearalkonium bentonite and stearalkonium hectorite / and mixtures thereof. Magnesium aluminium silicates clays are particularly preferred. An example is VEEGLIM® HV.

[0055] Preferably a 10% aqueous solution of the 2:1 layered silicate clay has a pH of 8 to 10.

[0056] It is preferred that the oral care composition comprises 0.01 wt.% to 5 wt.% of said 2:1 layered silicate clay, more preferably 0.1 to 3 wt% and still more preferably 0.1 to 2 wt% and most preferably 0.1 to 1 wt%. Oral care composition comprising 0.1 wt.% to 5 wt.% 2:1 layered silicate clay is also preferred. Xanthan gum

[0057] According to a first aspect of the present invention disclosed oral care composition includes xanthan gum.

[0058] Xanthan gum is a linear (1, 4)-linked b-D-glucose backbone (as in cellulose) with a trisaccharide side chain on every other glucose at C-3. This side chain comprises a glucuronic acid residue linked (1 , 4) to a terminal mannose unit and (1, 2) to a second mannose that connects to the backbone. Approximately 50% of the terminal mannose residues are pyruvated and the nonterminal residue usually carries an acetyl group at C-6.

[0059] Xanthan gum generally has a molecular weight of from 1 million to 50 million. Preferably xanthan gum has a viscosity ranging from 850 to 1 ,700 mPa.s (when measured at 25°C using a 1% solution of the gum in 1% KCI, on a viscometer of the Brookfield LV type, at 60 rpm using Spindle No.3).

[0060] Xanthan gum is available from several 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.

[0061] Preferably the xanthan gum derivatives can be prepared by etherification, esterification, acetalation, amidation or oxidation of non-derivatized xanthan gum. Preferred xanthan gum derivatives are prepared by reacting non-derivatized gum with quaternary ammonium compounds in an amount equal to or greater than the stoichiometric amount required for complete derivatization. The quaternary ammonium compounds are preferably having a single alkyl or alkenyl substituent containing from 13 to 24 carbon atoms, and / or two alkyl or alkenyl substituents of 12 to 24 carbon atoms per substituent. Most preferably, the quaternary ammonium compound is alkyl dimethylbenzylammonium chloride with an alkyl group containing from 13 to 24 carbon atoms.

[0062] Disclosed oral care composition includes from 0.1 wt.% to 5 wt.% xanthan gum. Preferably the oral care composition includes at least 0.2 wt.%, preferably at least 0.3 wt.%, still preferably at least 0.5 wt.% and most preferably at least 0.8 wt.%, but typically not more than 4.5 wt.%, still preferably not more than 3.5 wt.%, still further preferably not more than 3.2 wt.%, and most preferably not more than 3 wt.% by weight of xanthan gum. Other ingredients

[0063] Fluoride anticaries compound:

[0064] A further ingredient of the present composition is preferably a fluoride anticaries compound.

[0065] Illustrative of such fluoride compounds are sodium fluoride, potassium fluoride, calcium fluoride, magnesium fluoride, stannous fluoride, stannous monofluorophosphate, sodium monofluorophosphate and copper fluoride. Most preferred is sodium fluoride. These sources should release anywhere from about 25 to about 5,000 ppm of fluoride ion. The anticaries compound will normally be present in an amount ranging from 0.01 wt.% to about 5 wt.%, preferably from 0.1 wt.% to 2.5 wt.%, optimally from 0.2 wt.% to 1.5 wt.% by weight of oral care compositions.

[0066] Thickening silica:

[0067] Further preferably the oral care composition comprises 0 wt.% to 15 wt.% thickening silica. The primary function of thickening silica is to build viscosity, without increasing the level of abrasion (RDA) in the overall formulation. Also, they can be used as texturing agents in formulations that use alternative abrasives other than silica. These physical characteristics have effect on 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. In addition to having a substantial impact on the viscosity of the toothpaste system, the thickening silica also plays a role in the mouthfeel of the paste. If the level of the cleaning agent in the system is low, than the formulator may wish to use a less efficient thickener to achieve an overall solids level consistent with the desired mouthfeel.

[0068] This is especially the case when the compositions comprise silica as the abrasive. A variety of thickening silicas are commercially available. When present, preferred thickening silicas include AEROSIL®T series from Degussa or the CAB-O-SIL® series from Cabot Corporation, silica gels such as the SYLODENT® or SYLOX® series from W. R. Grace & Co or precipitated silica such as ZEOTHIX® 265 from J. M. Huber Corporation. Useful silica thickeners also include ZEODENT® 165, ZEODENT® 163 and / or 167 and ZEOFREE® 153, 177, and / or 265 silicas, all available from J. M. Huber Corporation. Other preferred thickening silicas include MFIL®, MFIL®-P (From Madhu Silica), SIDENT® 22 S and AEROSIL® 200 (Ex. Evonik Industries), SYLODENT® and PERKASIL®, TC 15 PQ thickening silicas from WR Grace & Company and Tixosil® 43 and 331 from Rhodia, synthetic finely divided pyrogenic silica such as those sold under the trademarks SYLOID® 244, SYLOID® 266 and AEROSIL® D-200. Zinc salt:

[0069] The oral care composition of the invention preferably includes a zinc salt. Preferably the composition comprises 0.1 to 3 wt% of said zinc salt, more preferably 0.1 to 2 wt% and most preferably 0.1 to

[0070] It is preferred that solubility of the compound of zinc at 20°C is 0.001 to 80 g / 100 g water.

[0071] It is preferred that the compound of zinc is at least one of zinc sulphate, 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 proprionate, zinc salicylate, zinc silicate, zinc stearate, zinc tartrate, zinc undecylenate, zinc phosphate, zinc ricinoleate or mixtures thereof. It is preferred that the zinc salt is selected from the group consisting of zinc chloride, zinc sulphate, zinc nitrate, zinc citrate, zinc gluconate, zinc acetate, zinc lactate, zinc salicylate, zinc gluconate and zinc ascorbate.

[0072] It is preferred that the zinc salt is water-soluble. By that it means having water solubility greater than 0.01 g / 100g water). For example, solubility (g / 100 g water) of some preferred sparingly water-soluble compounds of zinc is as follows: zinc citrate 6.11 and zinc lactate 1.4. Watersoluble compound of zinc whose solubility at 20°C is greater than 10 g / 100 g water include zinc sulphate, zinc chloride and zinc nitrate.

[0073] Preferably the composition includes from 0.1 wt.% to 5 wt.% zinc salt selected from zinc citrate, zinc gluconate, zinc acetate, zinc lactate, zinc salicylate, zinc gluconate, zinc ascorbate or mixtures thereof.

[0074] Alternatively, the zinc salt includes a combination of insoluble and soluble zinc salts. However, it is preferred that the zinc salt is water soluble.

[0075] Humectant:

[0076] Oral care composition of the invention preferably comprises 5 wt.% to 50 wt.% of one or more humectants. Alternatively, it is preferred that the oral composition of the invention comprises 5 wt.% to 40 wt.% humectant. Further preferably the composition comprises 10 wt.% to 40 wt.% humectant, more particularly 10 wt.% to 20 wt.% humectant. A particularly preferred humectant is sorbitol, generally available as 70% aqueous solution. Humectants are generally included in toothpastes for a soft a supple mouth feel. Humectants also reduce the tendency of toothpastes to lose moisture. It is preferred that the humectant is at least one of glycerine, sorbitol, maltitol and xylitol. Sorbitol is available as a 70% aqueous solution. Preferably the compositions comprise glycerine and sorbitol for a lubricated mouth feel, but their cumulative levels do not exceed the disclosed upper limit. Lower humectant content provides an effective way to reduce the cost of the product.

[0077] In one aspect of the invention, alternatively, the composition comprises less than 5 wt% humectant. It is preferred that the composition comprises upto 3 wt%, more preferably upto 2 wt% humectant. In this case it is also preferred that the oral care composition is humectant- free. By humectant-free is meant that the composition comprises not more than 1 wt% humectant in the composition, still more preferably 0 wt.% humectant, preferably where the humectant is sorbitol.

[0078] It is particularly preferred that when the dentifrice composition of the invention comprises less than 5 wt.% humectant, the abrasive is a calcium-based abrasive. It is particularly preferred that when the dentifrice composition of the invention comprises 5 wt.% to 40 wt.% humectant, the abrasive is a silica-based abrasive.

[0079] Buffering agent :

[0080] Preferably the composition of the invention 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.

[0081] The pH

[0082] Preferably the pH of the composition of the invention at 1 wt.% of the oral care composition in water as measured at 25°C is from 6.0 to 10.0, other preferred pH ranges includes from 6.5 to 9.5, preferably 6.5 to 9.0, preferably from 7.0 to 8.0. Most preferably the composition has a pH ranging from 6.5 to 10.

[0083] Surfactant:

[0084] Oral care composition, such as dentifrice composition, especially toothpastes generally contain a surfactant, also commonly referred to as sudsing agent. Suitable surfactants are those which are reasonably stable and provide foam throughout a wider pH range. It is preferred that compositions comprise an anionic surfactant. Anionic surfactants useful herein include the water-soluble salts of alkyl sulfates having from 8 to 20 carbon atoms in the alkyl radical (e.g., sodium alkyl sulfate) and the water-soluble salts of sulfonated monoglycerides of fatty acids having from 8 to 20 carbon atoms. Sodium lauryl sulfate and sodium coconut monoglyceride sulfonates are examples of anionic surfactants of this type.

[0085] Preferably the composition comprises from 0.25 wt.% to 12 wt.%, more preferably from 0.5 wt.% to 8 wt.%, and most preferably from 1 wt.% to 6 wt.% anionic surfactant.

[0086] Some anionic surfactants, in particular, sodium lauryl sulphate itself have antibacterial effect. Such action provides some degree of instant antibacterial effect. However, this effect is generally very short-lived. Other surfactants like nonionic, amphoteric or zwitterionic surfactants may also be included.

[0087] Nonionic surfactants can be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound which may be aliphatic or alkyl- aromatic in nature.

[0088] Examples of suitable nonionic surfactants include poloxamers (sold under trade name PLURONIC®), polyoxyethylene, polyoxyethylene sorbitan esters (sold under trade name TWEENS®), POLYOXYL® 40 hydrogenated castor oil, fatty alcohol ethoxylates, polyethylene oxide condensates of alkyl phenols, products derived from the condensation of ethylene oxide with the reaction product of propylene oxide and ethylene diamine, ethylene oxide condensates of aliphatic alcohols, long chain tertiary amine oxides, long chain tertiary phosphine oxides, long chain dialkyl sulfoxides, and mixtures of such materials.

[0089] Thickening system:

[0090] Further preferably the composition of the invention comprises a thickening system which comprises thickening silica and at least one of carboxymethyl cellulose, or guar gum. Other binders and thickeners such as sodium carboxymethyl cellulose gum arabic may also be included, as well as synthetic polymers such as polyacrylates and carboxyvinyl polymers such as Carbopol®.

[0091] Preferred toothpaste compositions may also include one or more other thickening agents such as carboxyvinyl polymers which include carbomers which are commercially available from B. F. Goodrich as the CARBOPOL® series, including CARBOPOL® 934, 940, 941 and 956. Other preferred grades include acrylates / Cw-30 alkyl acrylate cross polymers which are commercially available as ULTREZ® 21, PEMULEN® TR-1, and PEMULEN®TR-2, from Noveon Corporation. Preferred compositions can include 0.05 to 10 wt%, more preferably 0.1 to 5 wt%, and even more preferably 0.25 to about 4 wt% of other thickening agents.

[0092] Binder:

[0093] It is preferred that that composition according to the invention comprises a binder, which lends a good structure, especially to a dentifrice in the form of toothpaste. Cellulosic binders are especially preferred. Preferred cellulosic binders include cellulose ethers, which include hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), ethyl hydroxyethyl cellulose (EHEC), carboxymethyl cellulose (CMC), carboxymethylhydroxyethyl cellulose (CMHEC), hydroxypropylhydroxyethyl cellulose (HPHEC), methyl cellulose (MC), methylhydroxypropyl cellulose (MHPC), methylhydroxyethyl cellulose (MHEC), carboxym ethyl methyl cellulose (CMMC), hydrophobically modified carboxymethyl cellulose (HMCMC), hydrophobically modified hydroxyethyl cellulose (HMHEC), hydrophobically modified hydroxypropyl cellulose (HMHPC), hydrophobically modified ethylhydroxyethyl cellulose (HMEHEC), hydrophobically modified carboxymethylhydroxyethyl cellulose (HMCMHEC), hydrophobically modified hydroxypropylhydroxyethyl cellulose (HMHPHEC), hydrophobically modified methyl cellulose (HMMC), hydrophobically modified methyl hydroxypropyl cellulose (HMM HPC), hydrophobically modified methylhydroxyethyl cellulose (HMMHEC), and hydrophobically modified carboxymethylmethyl cellulose (HMCMMC).

[0094] Other cellulosic binders include cationic hydroxyethyl cellulose (cationic HEC), cationic hydrophobically modified hydroxyethyl cellulose (cationic HMHEC) and microcrystalline cellulose.

[0095] A highly preferred binder is Sodium carboxymethyl cellulose (SCMC). Particularly preferred sodium carboxymethyl celluloses include those with degree of substitution of from 0.6 to 0.99, preferably from 0.7 to 0.95.

[0096] The dentifrice compositions of the invention may contain optional further ingredients such as cosmetically acceptable carriers like starch and sucrose.

[0097] Alkali metal silicate:

[0098] The dentifrice compositions preferably include alkali metal silicate. The alkali metal is sodium or potassium, preferably sodium. Sodium silicate is generally available as 10 to 40 % aqueous solution, most common being 30 % solution. Sodium silicate is available as neutral sodium silicate or alkaline sodium silicate. Preferred toothpastes have neutral sodium silicate. Sodium silicate is available with varying ratios of Na2O: SiC>2.

[0099] Sodium silicate with Na2O: SiC>2 ratio in the range of 3.0 to 3.8 is preferred, more highly preferred range being 0.2 to 3, also preferred are ranges from 1.2 to 3 and 1.2 to 1.5. Preferred toothpastes include 0.1 wt.% to 5 wt.% silicate (on dry weight basis), also preferred are ranges from 0.2 wt.% to 3 wt.% and still preferred are 1.2 wt.% to 1.5 wt.%. Thus, a 30 % solution of sodium silicate is added to the composition in an amount in the range of 0.3 wt.5 to 16 wt.%.

[0100] Flavours:

[0101] Flavours such as peppermint and spearmint oils may also be included, as well as preservatives, colouring agents, pH adjusting agents, sweetening agents and so on. Suitable flavoring components include oil of Wintergreen, oil of peppermint, oil of spearmint, clove bud oil, menthol, anethole, methyl salicylate, eucalyptol, cassia, 1-menthyl acetate, sage, eugenol, parsley oil, oxanone, alpha-irisone, marjoram, lemon, orange, propenyl guaethol, cinnamon, vanillin, ethyl vanillin, heliotropine, 4-cis-heptenal, diacetyl, methyl-para-tert-butyl phenyl acetate, and mixtures thereof. Coolants may also be part of the flavor system. Preferred coolants are the paramenthane carboxyamide agents such as N-ethyl-p-menthan-3- carboxamide (known commercially as "WS-3®") and mixtures thereof. The flavour is generally from 0.001 to 5 wt%.

[0102] Anti-caries:

[0103] Anti-caries agents such as sodium- and stannous fluoride, aminefluorides, monosodiumfluorophosphate, casein, plaque buffers such as urea, pyruvates, arginine, small peptides, calcium lactate, calcium glycerophosphate, strontium polyacrylates may also be included. A preferred anti-caries agent is sodium monofluorophosphate. Other optional ingredients include vitamins such as Vitamin C, and plant extracts. Desensitising agents such as potassium bicarbonate, potassium oxalate, potassium nitrate as well as strontium salts may also be included.

[0104] Buffers:

[0105] Buffers and salts to buffer the pH and ionic strength of the compositions may also be included. Liposomes and other encapsulates may also be used to improve delivery or stability of active ingredients. Anti-calculus agents:

[0106] Furthermore, the oral care compositions may comprise anti-calculus agents such a alkali metal pyrophosphates, hypophosphite-containing polymers, organic phosphonates and phosphorcitrates.

[0107] Organic polyphosphate:

[0108] Dentifrice compositions of the invention may comprise an organic polyphosphate or a water- soluble salt thereof, said polyphosphate or said salt having average chain length of at least 4. It is preferred that the composition comprises 0.01 to 5 wt% organic polyphosphate, more preferably 0.05 to 4 wt%, further preferably 0.15 to 3 wt% and most preferably 0.15 to 2 wt%. It is preferred that the organic polyphosphate is phytic acid. In this case, it is in the acid form. Phytic acid, also known as myo-inositol hexaphosphate, or inositol hexaphosphoric acid, is a biodegradable chelating agent in liquid form with chelating performance comparable to that of EDTA. Herein, the term “phytate” includes phytic acid and its salts as well as the other polyphosphorylated inositol compounds.

[0109] When the organic polyphosphate is in the form of water-soluble salt, it preferably is 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 ferrum phytate.

[0110] Inorganic polyphosphate:

[0111] Dentifrice compositions of the invention may also comprise an inorganic polyphosphate or a water- soluble salt thereof, having average chain length of at least 4. It is preferred that the composition comprises 0.1 to 5 wt% inorganic polyphosphate, more preferably 0.5 to 4 wt%, further preferably 0.5 to 3 wt% and most preferably 0.5 to 2 wt%.

[0112] Inorganic polyphosphates useful in embodiments of the oral care formulations disclosed herein may consist of multiple phosphate molecules arranged in a linear and / or cyclic configuration. A polyphosphate is generally understood to consist of two or more phosphate molecules arranged primarily in a linear configuration, although some cyclic derivatives may be present. Although pyrophosphates (n=2) are technically polyphosphates, the polyphosphates desired are those having at least 4 phosphate groups. In one embodiment, such polyphosphates are made by blending linear and cyclic polyphosphates with sufficient concentration to yield a specific average chain length of at least 4. The inorganic polyphosphates may also be of branched form. It is preferred that the inorganic polyphosphate is pyrophosphate, trimetaphosphate, tripolyphosphate or ultrametaphosphate. The inorganic polyphosphate may be present in the form of a blend of linear and cyclic polyphosphates, comprising predominantly cyclic combinations of polyphosphate compounds, or “cyclic / cyclic combination polyphosphate blends”, or predominantly linear combinations of polyphosphate compounds, or “cyclic / linear combination polyphosphate blends,” for example tetrapolyphosphate 4 and hexametaphosphate 6. Polyphosphates larger than tetrapolyphosphate usually occur as amorphous glassy materials. Preferred in this invention are the linear polyphosphates having the formula: XO(XPOa)nX wherein X is sodium, potassium or ammonium and n averages from 4 to 125. Preferred polyphosphates are those having n averaging from about 6 to about 21 , such as those commercially known as Sodaphos (n=6), Hexaphos (n=13), and Glass H (n=21).

[0113] It is particularly preferred that the inorganic phosphate is hexametaphosphate. More particularly it is sodium hexametaphosphate. It has the structure:

[0114] The inorganic polyphosphate or a water-soluble salt thereof is other than a monofluorophosphate or a tripolyphosphate.

[0115] The weight ratio of the organic phosphate to inorganic phosphate is 1:10 to 1:0.05, more preferably 1:7 to 1 :0.1.

[0116] Preservative:

[0117] Toothpastes with calcium containing abrasives especially chalk are prone to bacterial growth.

[0118] Certain preservatives, e.g., methyl, ethyl, butyl, propyl and isopropyl esters of parahydroxybenzoic acid may be particularly useful against bacterial growth. A mixture of methyl, ethyl, butyl and propyl esters of parahydroxybenzoic acid is particularly preferred. The activity of this mixture can be enhanced by adding phenoxyethanol. Formaldehyde and dimethyl hydantoin are other preferred preservatives. Preservatives are generally included at 0.005 to 0.8 wt%.

[0119] Anti-bacterial agent:

[0120] Oral care composition may preferably include an anti-bacterial agents may also be included such as Triclosan, chlorhexidine, sanguinarine extract, metronidazole. Further examples of antibacterial agents are quaternary ammonium compounds such as cetylpyridinium chloride; bis- guanides such as chlorhexidine digluconate, hexetidine, octenidine, alexidine; halogenated bisphenolic compounds such as 2,2’ methylenebis-4(4-chloro-6-bromophenol).

[0121] Polymeric compounds which can enhance the delivery of active ingredients such as antibacterial agents can also be included.

[0122] Other optional ingredients:

[0123] Other optional ingredients that may be included are e.g., bleaching agents such as peroxy compounds e.g., potassium peroxy diphosphate, effervescing systems such as sodium bicarbonate / citric acid systems and colour change systems.

[0124] The compositions of the invention may also contain coloured particles suspended therein, e.g., coloured silica agglomerates or other coloured particles to impart a "speckled" appearance to the dentifrices. The oral care compositions may also contain stripes of a coloured paste, to provide for a visually clear gel-type dentifrice with coloured stripes or a separate-coloured phase.

[0125] The

[0126] In accordance with another aspect disclosed is a packaged product comprising oral care composition, preferably dentifrice composition, more preferably a toothpaste composition of the invention. The gel composition is preferably packaged in a collapsible tube such that it becomes easy to dispense a small amount without much dexterity. Alternatively, the composition is packaged in another type of container, such as a bottle or a jar, preferably with suitable means for dispensing a known quantity of the composition. The pack may be further packed in a suitable secondary package like a carton or a box, preferably with useful information about the contents and instructions for use. Typically, the oral care composition is packaged. In toothpaste or gel form, the composition may be packaged in a conventional plastic laminate, metal tube or a single compartment dispenser. The same may be applied to dental surfaces by any physical means, such as a toothbrush, fingertip or by an applicator directly to the sensitive area.

[0127] Method of use

[0128] The composition can be effective even when used in an individual’s daily oral hygiene routine. For example, the composition may be brushed onto the teeth. The composition may, for example, be contacted with the teeth for 1 one second to 20 hours. More preferably from 1 s to 10 hours, more preferably still from 10 s to 1 hour and most preferably from 30 s to 5 minutes. The composition may be used daily, for example for use by an individual once, twice or three times per day. When the oral care composition is a dual-phase composition, the two phases of the composition are mixed during application. The mixed phases are typically left on the teeth for from 3 minutes to 10 hours, more preferably from 3 minutes to 8 hours. The application may be carried out one to five times monthly.

[0129] Therapeutic treatments can be summarized as being measures directed to the maintenance (prophylaxis) or restoration (therapy) of health. ‘Therapy’ is concerned with bringing a body from a pathological state back to its normal, healthy state and with preventing a pathological state. Treatment by therapy is defined as any treatment which is designed to cure, alleviate, remove or lessen the symptoms of, or prevent or reduce the possibility of contracting any disorder or malfunction of the human or animal body.

[0130] According to a second aspect of the present invention disclosed is a composition according to the first aspect for promoting remineralization of teeth.

[0131] According to a third aspect of the present invention disclosed is 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 having abrasive selected from calcium-based abrasive, silica-based abrasive or mixtures thereof for promoting remineralization of teeth.

[0132] The invention will now be explained in detail with the help of the following non-limiting exemplary embodiments. A range of toothpaste compositions were formulated by following standard process. Test-3 and Test-6 were within the scope of the invention. Two non-fluoridated compositions (Test-7, Test- 8) were also prepared for comparative evaluation.

[0133] Table 1

[0134] All the compositions of Table 1 were subjected to a variety of standard tests to determine which of the compositions had any beneficial effect on the uptake of fluoride by the enamel. In addition, the compositions were subjected to a variety of tests to determine and compare their effects on remineralization and demineralization.

[0135] The test methods are summarized below and the observations are tabulated in Table 2 followed the inferences drawn from the data.

[0136] Surface micro hardness testing

[0137] Enamel specimen preparation: The test Enamel specimens obtained from human permanent teeth were used as the hard tissue test substrate. The teeth were sorted and cleaned. Selection of the tooth for further processing was based on the quality of the enamel and whether the particular tooth surface had sufficient size to obtain a large enough specimen to meet the study requirements. Tooth sections with white spots, cracks and other defects were rejected. The tooth sections were cut into 3 mm x 3 mm specimens using a low-speed saw. The teeth were stored in thymol during the sample preparation process. The 3 x 3 mm specimens were ground and polished to create flat surfaces to facilitate surface micro hardness testing using a polishing unit. The bottom side of the specimens was ground flat to a uniform thickness with 500-grit silicone carbide grinding paper. The topside of the specimen was ground using 1200-grit paper until most of the tooth surface was flattened. The specimens were serially polished using 4000-grit paper followed by 1 mm diamond polishing suspension. Specimens had at least 0.3 mm of enamel thickness. The specimens were sonicated in de-ionized water between each grinding / polishing step. As a final cleaning step, the polished specimens were sonicated in 2 % microliquid. The specimens were assessed with a magnification of 10X. To be accepted for the study the specimens were required to: not have any obvious cracks or other flaws in the enamel surface; b) have an evenly polished, high gloss enamel surface; c) have no contamination on the top surface from sticky wax or any other material.

[0138] Each specimen was mounted on an acrylic plate using wax. The sides of each specimen were covered with a varnish so that only the enamel surface was exposed. On the enamel surface, a sound reference area of approximately 3 mm x 1 mm was created on the specimens using acid-resistant, clear nail varnish. Eight specimens per group were used for this for each test.

[0139] Lesion preparation:

[0140] 1. Methyl cellulose system

[0141] Abrade the labial surfaces of human teeth to give an area of approximate width (mesio- distally) of 4mm. Polish the abraded area on a glass plate with 1200 grade alumina slurry. Cut sections from the polished area of approximate dimension 3,5 x 3,5 mm across the width of the tooth. Paint the sides of the sections using acid-resistant nail varnish, and paint the polished area to leave a window of approximately 3 mm x 3mm. Mount the enamel sections polished face upwards in dental wax in the base of a crystallising dish of at least 60mm depth.

[0142] Boil 500 mL demineralised water, and measure about 460 mL into a beaker, stirring, with a thermometer in the water. Weigh out 40g methyl cellulose (high substitution). When the water has cooled to about 80°C, add the methyl cellulose, still stirring. When the suspension has cooled to about 50°C, pour onto the enamel sections to an approximate depth of 2.5cm (the temperature at which the mixture is poured at varies depending on the temperature at which the grade of methyl cellulose being used ‘sets’). Cover the dish and refrigerate at 4°C for 2 / 3 hours, until clear. Ensure that the enamel windows are not covered by any air bubbles as this will retard lesion formation. 2. Acid Lactic System 0. 1 mol / l, pH 4.6

[0143] Weigh out 9g ± 1% lactic acid, if 100%purity, (our lactic acid is 88% pure, so to get 9g lactic acid needs 9 x (100 / 88) or 10.23g). Add to 100 ml demineralised water, in a small conical flask, and gently boil, with stirring, on a hotplate for 1 hour. Put a small watch glass over the flask to prevent the acid boiling dry. (The lactic acid forms the acid anhydride in the concentrated form and this boiling hydrolyses it.) Let the acid cool, and make up to a total volume of about 970 ml in a beaker, and adjust the pH to 4.6 ± 0.02 using saturated KOH, whilst stirring. Add the acid to a 11 volumetric flask and make up to the line with demineralised water. Cover the methyl cellulose with a piece of filter paper and add 2.5 cm lactic acid. Incubate at 37°C for 8 days, after that remove the acid / gel system, rinse the teeth in copious amounts of demineralised water and store dry until needed.

[0144] T reatment with T oothpaste

[0145] Samples were mounted lesion uppermost, in dental wax, in the base of a crystallizing dish for treatment with products. This consisted of:

[0146] • Immersion in a 1:3 toothpaste: water slurry overnight, at 37 °C with periodic agitation for paste formulations;

[0147] After treatment, samples were rinsed thoroughly in deionized water.

[0148] Acid Etching

[0149] The lesion samples were mounted in dental wax on glass microscope slides. A 50pl aliquot of 1 mol / l perchloric acid was pipetted onto each lesion and left for 10 min. Subsequently the acid was drawn from the lesion into individual pre-weighed vials under vacuum. Each lesion was then rinsed with three aliquots of 50pl of 1 mol / l sodium acetate, which were combined with the acid in the vials using the same vacuum technique.

[0150] Analysis of Fluoride

[0151] The fluoride activity of the etching solution from each lesion was determined using the pH meter connected with a combination fluoride ion-selective electrode, system suitable for the analysis of small volumes. Before the fluoride measurement a calibration curve was calculated (via linear regression analysis) using daily prepared fluoride standard solutions. At the end of the experiment all the homemade fresh solutions are wasted

[0152] Example 2: Determination Remineralization and Demineralization The toothpaste composition as provided in table 2 was Remineralization

[0153] First the teeth sample was immersed for five minutes in toothpaste slurry. The toothpaste slurry was prepared by mixing one part of toothpaste composition with three parts of deionized water having 10 UI / mL alkaline phosphatase.

[0154] Next the teeth sample was immersed for one hour in an acidic buffer. The acidic buffer was prepared by mixing 50 mmol / L acetic acid and 1.5 mmol / L KH2PO4; pH5.0.

[0155] After this, the teeth sample was immersed for one minute in a neutral buffer. The neutral buffer was prepared by mixing 20 mmol / L HEPES and 1.5 mmol / L KH2PO4; pH 7. This cycle was repeated 6 times a day for 2 days. During the night the enamel chips are stored into Neutral buffer solution. Note: retain the acidic buffers for analysis.

[0156] Teeth sample was washed after each step to thoroughly rinse off the active agents from the previous steps.

[0157] The extent of remineralisation is assessed by micro-hardness analysis of the enamel blocks, before and after pH-cycling. 4 readings were taken per specimen and the level of remineralisation is expressed as a % of hardness Vickers (Hardness Vickers = HV) restored, as follow:

[0158] % HV Restored = (A HV / HV Baseline) * 100 where A HV was calculated as follow: HV after - HV before treatment.

[0159] In this study the previous mentioned toothpaste formulations were tested using an experimental design matrix ensuring random allocation of tested toothpaste formulations

[0160] Demineralisation

[0161] First the teeth sample was immersed for five minutes in toothpaste slurry. The toothpaste slurry was prepared by mixing one part of toothpaste composition with three parts of deionized water having 10 UI / mL alkaline phosphatase.

[0162] Next the teeth sample was immersed for one hour in an acidic buffer. The acidic buffer was prepared by mixing 50 mmol / L acetic acid and 1.5 mmol / L KH2PO4; pH5.0.

[0163] After this, the teeth sample was immersed for one minute in a neutral buffer. The neutral buffer was prepared by mixing 20 mmol / L HEPES and 1.5 mmol / L KH2PO4; pH 7. This cycle was repeated 6 times a day for 2 days. During the night the enamel chips are stored into Neutral buffer solution. Note: retain the acidic buffers for analysis Teeth sample was washed after each step to thoroughly rinse off the active agents from the previous steps. Efficacy was assessed by micro-hardness analysis of the teeth sample, before and after pH-cycling.

[0164] Four readings were taken for each teeth sample and demineralisation expressed as a percentage reduction in hardness.

[0165] Efficacy was assessed by micro- hardness analysis of the enamel blocks, before and after pH- cycling. 4 readings were taken per specimen and demineralization expressed as a percentage reduction in Vickers hardness (% HV Reduction), as follow:

[0166] %HV Reduction = (Mean HV after treatment-Mean HV before treatment / Mean HV before treatment) X 100

[0167] Table 2

[0168] The data provided in table 2 shows that when the composition has a combination of 1 :1 layered silicate clay (kaolin), the 2:1 layered silicate clay (Veegum® HV) and xanthan gum (Test-3, Test-6) it provides improved remineralization and reduces demineralization.

Claims

CLAIMS1. An oral care composition comprising:(i) an abrasive selected from calcium-based abrasive, silica-based abrasive, or mixtures thereof;(ii) 1:1 layered silicate clay; and,(iii) 2:1 layered silicate clay; wherein said composition comprises 0.1 wt.% to 5 wt.% xanthan gum.

2. A composition according to claim 1 wherein said 1 :1 layered silicate is a kaolinite.

3. A composition according to claim 2 wherein the kaolinite is selected from the group consisting of kaolin, halloysite, nacrite and dickite.

4. A composition according to claims 1 to 3 wherein said 2:1 layered silicate is a smectite clay.

5. A composition according to claim 4 wherein said smectite clay is selected from the group consisting of phyllosilicates, montmorillonites, bentonites, hectorites, sodium magnesium silicates, aluminium magnesium silicate, organically modified smectites and organically modified montmorillonite clay.

6. A composition according to claim 5 wherein the smectite clay is magnesium aluminium silicate clay.

7. A composition according to one of the preceding claims wherein said composition comprises 10 wt.% to 70 wt% humectant.

8. A composition according to claim 7 wherein said humectant is selected from the group consisting of glycerin, sorbitol, xylitol, butylene glycol, propylene glycol and mixtures thereof.

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

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

11. A composition according to any one of the preceding claims wherein the abrasive is present in an amount ranging from 10 wt.% to 50 wt.% in the composition.

12. A composition according to any one of the preceding claims wherein said composition comprises a buffering agent selected from the group consisting of alkali metal silicate, alkali metal hydroxide, alkali metal bicarbonate, alkali metal carbonate and alkali metal pyrophosphate, arginine, and combinations thereof.

13. A composition one of the preceding claims wherein pH of said composition is from 6.0 to 10.0.

14. A composition as claimed in any one of the preceding claims for promoting remineralization of teeth.

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 having abrasive selected from calcium-based abrasive, silica- based abrasive or mixtures thereof for promoting remineralization of teeth.

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