Oral care composition

Abstract

The present invention relates to an oral care composition. Particularly it relates to oral care composition having improved sensorials like flavour profile and foaming properties. It is desired to provide an oral care composition which exhibits improved foaming. It is also desired to provide improved flavour profile and flavour impact without necessary increasing the levels of the flavoring agent as this may increase the cost of the composition. The present inventors have found that an oral care composition having specific levels of thickening silica in combination with xanthan gum provides sensorial improvement. The composition was found to provide improved foaming performance and improved flavour release. According to a first aspect of the present invention disclosed is an oral care composition comprising a combination of xanthan gum and less than 8 wt.% thickening silica.

Description

[0001]P0000501 CPL 1 ORAL CARE COMPOSITION Field of the Invention 5 The present invention relates to an oral care composition. Particularly it relates to oral care composition having improved sensorials like flavour profile and foaming properties. Background of the Invention In oral care compositions, foaming plays a vital role in consumer acceptance. Improved foaming 10 is often perceived by consumers as being directly related to improved cleaning. In addition to foaming, flavor impact and the taste of the composition, may often be of more importance to consumers. It is highly desirable that oral care composition imparts a fresh and clean feeling as this provides consumers with a signal of continuing freshness and cleanliness. 15 In addition to the feeling of cleanliness, consumers also want to experience the benefits of oral care actives like anti-microbial agents, for example, through their oral care regimen. Since many efficacious oral care components have undesirable taste, color, odor or clarity, efforts to improve these characteristics are common in the art. 20 The ability to formulate a consumer acceptable oral care composition, however, raises challenges as many of the components used to impart a flavor, deliver a benefit, or that are part of the base for the oral care composition add unwanted tastes and / or sensations along with the targeted benefit for which they are added. Thus, formulating oral care compositions can be a balancing act between acceptable sensorials, such as foaming, acceptable flavor and 25 acceptable benefits. WO2015 / 167488 (Colgate) discloses an oral care composition having xanthan gum and zinc salt. 30 WO 2017 / 117135 (Colgate) discloses a striped oral care composition which has at least one zinc ion source, a thickening system having a combination of xanthan gum and carboxymethyl cellulose. WO 2016 / 196131 A1 (Colgate) discloses an oral care composition which achieves high levels 35 of foam in presence of high salt levels by the incorporation of a dual surfactant system that does not include a non-ionic surfactant. P0000501 CPL 2 There is still an unmet need to provide an oral care composition which exhibits improved foaming. It is also desired to provide improved flavour profile and flavour impact without necessarily increasing the levels of the flavoring agent as this may increase the cost of the composition and also an oral care composition which provides good zinc bioavailability and 5 good antimicrobial benefits. Summary of the Invention The present inventors have found that an oral care composition having specific low levels of thickening silica in combination with xanthan gum provides sensorial improvement. The 10 composition was found to provide improved flavour performance and improved flavour release. According to a first aspect of the present invention disclosed is an oral care composition comprising a combination of xanthan gum and less than 8 wt.% thickening silica. The present inventors have also found that the composition provides for good zinc bioavailability without affecting the flavour profile. 15 According to a first aspect of the present invention provided is an oral care composition comprising: i. less than 8 wt.% thickening silica; ii. xanthan gum; and, 20 iii. silica based abrasive. Detailed Description of the Invention According to a first aspect of the present invention disclosed is an oral care composition which comprises thickening silica, xanthan gum and silica abrasive. 25 Xanthan gum Oral care composition according to the first aspect of the present invention comprises a xanthan gum. The xanthan gum is polysaccharide having a molecular weight ranging from 1,000,000 to 10,000,000. Xanthan gum has a primary structure consisting of regular repeating units, each 30 containing five sugars: two glucose, two mannose, and one glucuronic acid. The main chain is built up of β-D-glucose units linked through the 1- and 4-positions, i.e., a chemical structure the same as cellulose. A three-sugar side chain is linked to the 3-position of every other glucose residue in the main chain. About half of the terminal D-mannose residues contain a pyruvic acid residue linked to the 4- and 6-positions. Preferably the xanthan gum, has a degree of 35 substitution of less than 0.4 carboxylate groups per sugar residue. P0000501 CPL 3 Preferably the xanthan gum has a weight average molecular weight (Mw) ranging from 5 to 15 million Daltons, preferably ranging from 5.5 million Daltons to 10 million Daltons, more preferably form 6 million Daltons to 8 million Daltons. 5 Preferably the xanthan gum has a viscosity ranging from 850 mPa.s 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). Xanthan gum suitable for use in the present application is available from several commercial 10 suppliers Keltrol® T plus, Keltrol® SF, and Keltrol T being particularly preferred. Preferably the xanthan gum derivatives can be prepared by etherification, esterification, acetylation, amidation, or oxidation of non-derivatized xanthan gum. Preferred xanthan gum derivatives are prepared by reacting non-derivatized gum with quaternary ammonium 15 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 20 from 13 to 24 carbon atoms. Preferably the oral care composition includes from 0.1 wt.% to 5 wt.% xanthan gum, more preferably from 0.1 wt.% to 1 wt.%, still preferably from 0.1 wt.% to 0.75 wt.%, further preferably from 0.1 wt.% to 0.5 wt.% xanthan gum. Preferably the oral care composition comprises at least 25 0.15 wt.%, still preferably at least 0.2 wt.%, still preferably at least 0.25 wt.%, most preferably at least 0.3 wt.% xanthan gum, but typically not more than 4 wt.%, still preferably not more than 3 wt.%, still further preferably not more than 2.5 wt.%, still more preferably not more than 1 wt.% and most preferably not more than 0.75 wt.%, still more preferably not more than 0.5 wt.%, further preferably not more than 0.4 wt.% of xanthan gum based on the weight of the 30 transparent dentifrice composition. Preferred oral care composition includes from 0.1 wt.% to 1 wt.% xanthan gum. Preferably the transparent dentifrice composition includes at least 0.15 wt.%, preferably at least 0.16 wt.%, still preferably at least 0.17 wt.% and most preferably at least 0.18 wt.%, but typically not more than 35 1 wt.%, still preferably not more than 0.8 wt.%, still further preferably not more than 0.6 wt.%, and most preferably not more than 0.4 wt.% by weight xanthan gum. P0000501 CPL 4 Zinc ion source Preferably the oral care composition comprises a zinc ion source. Zinc ion source is preferably a zinc compound, still preferably a zinc salt. Zinc ions have been found to help in the reduction of gingivitis, plaque, sensitivity, and improved breath benefits. Many zinc compounds, however, 5 are sparingly soluble and hence must be used in relatively large amounts to provide an effective amount of zinc ions. Unfortunately, many zinc compounds also have an unpleasant consumer astringency, especially when used in relatively high concentration. Typically, when zinc compound is used in an amount greater than 1 wt.%, more preferably in amounts greater than 1.2 wt.% the zinc compound typically has an astringency which negatively impacts the flavour 10 performance. It was found that the careful balance of the zinc compound in the composition according to the present invention improved the flavour profile while maintaining the desired bioavailability of zinc ion source in the composition. The composition according to the present invention allow for an effective incorporation of zinc ions into an oral care composition. 15 Examples of suitable zinc compounds that may serve as zinc ion sources include, for example, zinc oxide, zinc citrate, zinc sulfate, zinc chloride, zinc lactate, zinc gluconate, zinc malate, zinc tartrate, zinc carbonate, zinc phosphate, and other zinc salts. Preferably, the zinc ion source is zinc citrate, still preferably zinc citrate trihydrate. Preferably the zinc salt is selected from the group consisting of zinc lactate, zinc oxide, zinc chloride, zinc phosphate, and zinc citrate. 20 Preferably, the zinc ion source is zinc sulphate, still preferably zinc sulphate heptahydrate. Preferably the zinc sulphate has a solubility in water ranging from 38 g / L to 50 g / L. Preferably the oral care composition of the invention preferably includes a zinc salt. Preferably the composition comprises 0.1 wt.% to 3 wt.% of said zinc salt, more preferably 0.1 to 2 wt%. Preferably the zinc salt is water soluble. More preferably the zinc salt is zinc citrate, zinc 25 sulphate and mixtures thereof. The present invention also provides an oral care composition which has better zinc delivery and better remineralization benefits. Zinc ions are derived from the zinc compound, i.e., zinc ion source, present in the oral care composition in an effective amount. An effective amount of zinc ions is defined as from at least 30 1000 ppm zinc ion, preferably 2,000 ppm to 15,000 ppm. More preferably, zinc ions are present in an amount from 3,000 ppm to 13,000 ppm and even more preferably from 4,000 ppm to 10,000 ppm. This is the total amount of zinc ions that is present in the compositions for delivery to the tooth surface. The amount of zinc compound (zinc ion source) employed in the oral composition of the invention can vary from 0.01 wt.% to 1.5 wt.%, based on the total weight of 35 the composition, typically from 0.1 wt.% to 1.3 wt., or 0.1 wt.% to 1 wt.%, based on the total weight of the oral care composition. P0000501 CPL 5 Thickening silica According to the first aspect of the present invention the oral care composition comprises less than 8 wt.% thickening silica. In another aspect, the oral care composition comprises less than 6 wt% thickening silica. The primary function of thickening silica is to build viscosity, without 5 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. Preferably the thickening silica is an amorphous inorganic silica. Preferably the oral care composition comprises from 0.1 wt.% to 7.5 wt.% thickening silica, still more preferably from 4 wt.% to 10 7.5 wt.% thickening silica, more preferably from 4 wt% to 6wt % of thickening silica. Preferably the oral care composition comprises not less than 0.5 wt.% still preferably not less than 1 wt.%, still preferably not less than 1.5 wt.%, further preferably not less than 2 wt.%, and most preferably not less than 4 wt.% thickening silica by weight of the oral care composition, preferably the oral care composition has no more than 8 wt.% thickening silica, still preferably 15 not more than 7.5 wt.%, still more preferably not more than 6 wt.%, furthermore preferably not more than 5.3 wt.%. Preferably the composition includes less than 7.5 wt.% thickening silica. The primary function of thickening silica is to build viscosity, without increasing the level of abrasion (RDA) in the overall 20 formulation. 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 25 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 & 30 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. Silica based abrasive Oral care composition according to the present includes a silica-based abrasive. Preferably the 35 -based abrasive comprises mixture of two different types of silica-based abrasive which provides for effective cleaning and whitening, while minimizing abrasive damage. P0000501 CPL 6 Preferably the silica-based abrasive may be an amorphous silica such as Zeodent 105, Zeodent 114 marketed by J.M. Huber Chemicals Division, Havre de Grace, Md.21078); Sylodent 783 and Sylodent VP5 (marketed by Davison Chemical Division of W.R. Grace k Company); or Sorbosil AC 43 (from PQ Corporation). 5 Preferably the silica-based abrasive may be a precipitated silica. Preferably the precipitated silica has a pellicle cleaning ratio (PCR) of greater than 85 when tested at 20% loading. In one embodiment this precipitated silica also has a mean particle size D50 rangin from 5 to 15 pm and an oil absorption of from 40 to 120 cm3 / 100g silica. The cleaning efficacy of the precipitated 10 silica is expressed using the pellicle cleaning ratio (PCR). This is typically measured at 20 % silica loading. This high cleaning silica preferably has a PCR value of greater than 85. Preferably the silica-based abrasive may be mixture of abrasive with different abrasivity. Further preferably the abrasive silica comprises medium- and high-abrasive silica, where 15 medium-abrasive silica is preferably in majority. Their relative proportions may vary. Preferably the silica-based abrasive comprises a combination of a first silica abrasive and a second silica abrasive. Preferably the first silica abrasive includes a hydrated silica with RDA (Radioactive dentine Abrasion) ranging from 130 to 180, more preferably an RDA ranging from 20 130 to 160. Preferably the PCR value (Pellican cleaning ratio) ranges from 85 to 100%, still more preferably from 85% to 95%. Preferably weight average particle size of the abrasive silica D90 is not more than 30 micrometers. Preferably the first silica-based abrasive is present in the oral care composition in an amount ranging from 8 wt.% to 10 wt.%. Preferably the silica abrasive has a refractive index ranging from 1.441 to 1.445. 25 Preferably the second silica abrasive includes a hydrated silica with RDA ranging from 160 to 330, more preferably from 160 to 220. Preferably the PCR value (Pellican cleaning ratio) ranges from 110 to 115%. Preferably weight average particle size of the abrasive silica is D90 is not more than 12.2 micrometers. Preferably the silica-based abrasive is present in the oral care 30 composition in an amount ranging from 0.5 wt.% to 3 wt.%, still preferably from 0.5 wt.% to 2.5 wt.%, further preferably from 1 wt.% to 2.5 wt.%. Preferably the second silica abrasive has a weight average particle size (D50) ranging from 7 micrometers to 11 micrometers. Preferably the silica abrasive has a refractive index ranging from 1.435 to 1.445. P0000501 CPL 7 Preferably the oral care composition according to the first aspect of the present invention comprises from 9 wt.% to 12.5 wt.% silica-based abrasive, still preferably from 9 wt.% to 11 wt.% silica-based abrasive. 5 Preferably the abrasive silica has a 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 µm, 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.I. of between 1.435 and 1.445 are Tixosil 63 and 73 ex Rhone 10 Poulenc; Sident 10 ex Degussa; Zeodent 113 ex Zeofinn; Sorbosil AC 77 ex Ineos having an R.I. of approximately 1.440. Other examples include the Sylodent® and Syloblanc® range of abrasive silicas from Grace. Preferably, the abrasive silica is a precipitated silica. Suitable precipitated silicas for use as 15 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) 20 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. Preferably the oral care composition according to the first aspect of the present invention 25 comprises from 9 wt.% to 12.5 wt.% silica-based abrasive, still preferably from 9 wt.% to 11 wt.% silica-based abrasive. 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 12 wt.%, still preferably not more than 11 wt.%, still further preferably not more than 10.8 wt.%, and most 30 preferably not more than 10 wt.% by weight of the silica-based abrasive. The oral care composition according to the first aspect of the present invention includes no calcium-based abrasive. More preferably the composition of the present invention has no additional abrasive including but are not limited to: aluminum oxide, aluminum silicate, calcined 35 alumina, bentonite, other siliceous materials, insoluble phosphates, natural calcium carbonate (NCC), precipitated calcium carbonate (PCC), and mixtures thereof. In some embodiments, at P0000501 CPL 8 least one of the additional abrasives is a calcium carbonate abrasive, such as precipitated calcium carbonate (PCC) or natural calcium carbonate (NCC). Cellulose thickening agent 5 Preferably the oral care composition includes a cellulose thickening agent. Preferably the cellulose thickening agent is carboxy methyl cellulose (CMC). Preferably the cellulose thickening agent has carboxylate group along their backbone. Preferably the degree of substitution of carboxy methyl cellulose is at least 0.9 carboxylate 10 group per sugar residue. The cellulose based thickening agent, is preferably a CMC comprising a backbone ranging from 8 to 12 cellulose units, such as 8 cellulose units (CMC8), 9 cellulose units (CMC9), or 12 cellulose units (CMC12). More preferably the CMC is a sodium salt, more preferably SCMC 9H. 15 Preferably the cellulose thickener is a substituted carboxymethyl cellulose. Still preferably the carboxymethyl cellulose has an average degree of substitution (DS) per anhydroglucose unit more than 0.7, still preferably the average degree of substitution (DS) per anhydroglucose unit ranging from 0.8 to 1. As used herein, the term "degree of substitution (DS)" generally refers to carboxymethyl cellulose with the average number of carboxymethyl groups substituted per unit 20 of anhydroglucose. Preferably the oral care composition according to the present invention includes a cellulose thickening agent in an amount ranging from 0.2 wt.% to 2 wt.%. Preferably the oral care composition includes from 0.1 wt.% to 0.8 wt.%, more preferably 0.2 wt.% to 0.75 wt.% 25 carboxymethyl cellulose, still preferably from 0.5 wt.% to 0.8 wt.%, further preferably from 0.55 wt.% to 0.7 wt.% carboxymethyl cellulose. Preferably the oral care composition comprises at least 0.2 wt.%, still preferably at least 0.3 wt.%, still preferably at least 0.4 wt.%, most preferably at least 0.5 wt.% of carboxymethyl cellulose, but typically not more than 0.8 wt.%, still preferably not more than 0.75 wt.%, still further preferably not more than 0.73 wt.% 30 carboxymethyl cellulose based on the weight of the oral care composition. Preferred ingredients Humectant: Preferably the oral care composition includes a humectant. Any orally acceptable humectant 35 may be used. Non-limiting examples includes polyhydric alcohols such as glycerin, sorbitol, xylitol, or low molecular weight polyethylene glycols. Many humectants also function as P0000501 CPL 9 sweeteners. Preferably the humectant is sorbitol. Sorbitol is generally incorporated in the form of an aqueous solution; the aqueous solution preferably is a 70% sorbitol. Preferably the oral care composition includes a humectant in an amount ranging from 1 wt.% to 5 70 wt.%, for example from 5 wt.% to 50 wt.%, from 10 wt.% to 40 wt.%, or from 15 wt.% to 30 wt.%, by weight based on the total weight of the composition. More preferably the oral care composition comprises from 35 wt.% to 70 wt.% humectant. Preferably the composition disclosed herein is substantially free of glycerin. As used herein, the 10 term "substantially free of glycerin" means that the composition comprises no added glycerol, more preferably it means that the oral care composition comprises 0 wt.% by weight of glycerin. Preferably the oral care composition includes from 50 wt.% to 65 wt.% sorbitol, more preferably 15 from 52 wt.% to 65 wt.% still preferably from 55 wt.% to 60 wt.%, further preferably from 58 wt.% to 60 wt.% sorbitol, wherein the sorbitol is in the form of a 70% solution. Preferably the transparent dentifrice composition comprises at least 52 wt.%, still preferably at least 55 wt.%, still preferably at least 56 wt.%, most preferably at least 57 wt.% of sorbitol, but typically not more than 65 wt.%, still preferably not more than 63 wt.%, still further preferably not more than 20 62 wt.%, still more preferably not more than 61 wt.% and most preferably not more than 60.5 wt.%, still more preferably not more than 60 wt.% of sorbitol based on the weight of the oral care composition, wherein the sorbitol is in the form of a 70% solution. Anti-calculus agent: 25 Preferably the oral care composition includes an anti-calculus agent. The anti-calculus agent may be selected from a phosphate; a pyrophosphate; a polyphosphate; a phosphonate; a polyphosphonate; and mixtures thereof. In some embodiments, the pyrophosphate is selected from: a dialkali metal pyrophosphate salt; a tetra-alkali metal pyrophosphate salt; and mixtures thereof in their un-hydrated as well as hydrated forms. More preferably the anti-calculus agent 30 is a phosphate, pyrophosphate, or mixtures thereof. Preferably, tetrasodium pyrophosphate (TSPP) and sodium tripolyphosphate (STPP) are used as the anti-calculus agents. The amount of anti-calculus agent optionally present in the composition of the invention is from 0.1 wt.% to 10 wt.%, more preferably from 1 wt.% to 5 wt.%, by weight of the composition. 35 P0000501 CPL 10 Fluoride source: The oral care composition disclosed herein may also comprise a fluoride source. Fluoride-containing compounds have a beneficial effect on the care and hygiene of the oral cavity, e.g., diminution of enamel solubility in acid and protection of the teeth against decay. 5 Examples of suitable fluoride sources include stannous fluoride, sodium fluoride, potassium fluoride, potassium stannous fluoride (SNFZ-KF), potassium fluor zirconate, sodium hexafluoro stannate, stannous chlorfluoride, sodium mono fluorophosphate (MFP), sodium fluorosilicate, ammonium fluorosilicate, amine fluoride, and ammonium fluoride and combinations thereof. 10 Preferably the fluoride ion source includes stannous fluoride, sodium fluoride, amine fluorides, sodium monofluorophosphate, as well as mixtures thereof. Preferably, the oral care composition may also contain a source of fluoride ions or fluorine-providing ingredient in amounts sufficient to supply 50 to 5000 ppm fluoride ion, e.g., from 100 to 1000, from 200 to 500, or 250 ppm fluoride ion. Fluoride ion sources may be added to the compositions at a level of 0.001 wt.% to 15 10 wt.%, e.g., from 0.003 wt.% to 5 wt.%, more preferably from 0.01 wt.% to 1 wt.% or 0.05 wt.% to 0.2 wt.%. However, it is to be understood that the weights of fluoride salts to provide the appropriate level of fluoride ion will obviously vary based on the weight of the counter ion in the salt, and one of skill in the art may readily determine such amounts. A preferred fluoride salt may be sodium fluoride. 20 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. 25 Water content: The term “water content” used herein means the total concentration of water, including any free water and all water contained in the ingredients. The oral care composition according to the first aspect of the present invention has a water content present which is preferably less than 30 40 wt.%. The water content present in the oral care composition is preferably less than 40 wt.%, still preferably less than 39 wt.%, still more preferably less than 38 wt.%, also preferred are those composition where the water content is less than 35 wt.%. Preferably the oral care composition has a water content which is at least 15 wt.%, still preferably at least 17 wt.%, still more preferably at least 18 wt.% and furthermore preferably at least 20 wt.%. Preferably the 35 composition has a water content ranging from 15 wt.% to 35 wt.%. Preferably the oral care P0000501 CPL 11 composition has a free water content of at least 10 wt.%, still preferably at least 15 wt.%, more preferably at least 20 wt.% by weight of the oral care composition. Buffering agent: 5 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. Surfactant: 10 The oral care composition disclosed may preferably include one or more surfactants. Non- limiting examples of the surfactant include anionic surfactant, nonionic surfactant, cationic surfactant, amphoteric surfactant, and mixtures thereof. Preferably the anionic surfactant is a sodium lauryl sulphate. 15 Suitable anionic surfactants include, for example, water-soluble salts of C8 to C20 alkyl sulfates, sulfonated monoglycerides of C8 to C20 fatty acids, sarcosinates and taurates; for example, sodium lauryl sulfate, sodium coconut monoglyceride sulfonate, sodium lauryl sarcosinate, sodium lauryl isethionate, sodium laureth carboxylate and sodium dodecyl benzenesulfonate, and mixtures thereof. 20 Examples of suitable surfactants include water-soluble salts of higher fatty acid monoglyceride mono sulfates, such as the sodium salt of mono sulfated monoglyceride of hydrogenated C12- C16 fatty acids; higher alkyl sulfates such as sodium lauryl sulfate; alkyl aryl sulfonates such as sodium dodecyl benzene sulfonate; higher alkyl sulfoacetates, such as sodium lauryl 25 sulfoacetate; higher fatty acid esters of 1,2-dihydroxypropane sulfonate. Most preferably the surfactant is a sodium lauryl sulphate surfactant. Preferably the sodium lauryl sulphate surfactant is present in an amount ranging from 0.5 wt.% to 4 wt.%, 1 wt.% to 3.5 wt.%, still more preferably from 1.5 wt.% to 3 wt.% in the composition. 30 Examples of suitable amide surfactants include the substantially saturated higher aliphatic acyl amides of lower aliphatic amino carboxylic compounds, such as those having 12-16 carbons in the fatty acid, alkyl, or acyl radicals; and the like. Examples of the amides include N-lauryl sarcosine, and the sodium, potassium, and ethanolamine salts of N-lauryl, N-myristoyl, or N-palmitoyl sarcosine. 35 P0000501 CPL 12 Examples of suitable nonpolar surfactants include one more selected from polymers and copolymers of ethylene glycol and propylene glycol, e.g., poloxamers, i.e., nonionic triblock copolymers composed of a central hydrophobic chain of polyoxypropylene (poly(propylene oxide)) flanked by two hydrophilic chains of polyoxyethylene (poly(ethylene oxide)). The 5 approximate lengths of the two PEG blocks may be, in some embodiments, an average of about 50-150 repeat units, e.g., about 100 repeat units while the approximate length of the propylene glycol block is an average of about 25-75 repeat units, e.g., about 50-60 repeat units. In one embodiments, the poloxamer may be poloxamer 407, also known by BASF tradename Pluronic F127, which may be present in an amount ranging from 0.5 wt.% to 2 wt.%, such as 10 1 wt.%, by weight. Suitable nonionic surfactants include, for example, poloxamers, polyoxyethylene sorbitan esters, fatty alcohol ethoxylates, alkylphenol ethoxylates, tertiary amine oxides, tertiary phosphine oxides, dialkyl sulfoxides, and mixtures thereof. It is also preferred that the 15 composition includes 0 wt.% nonionic surfactant. Preferably the surfactant is an amphoteric surfactant. Examples of amphoteric surfactant includes cocamidopropyl betaine, and cocamidopropyl betaine lauryl glucoside; condensation products of ethylene oxide with various hydrogen containing compounds that are reactive 20 therewith and have long hydrocarbon chains (e.g., aliphatic chains of from 12 to 20 carbon atoms), which condensation products (ethoxamers) contain hydrophilic polyoxyethylene moieties, such as condensation products of poly (ethylene oxide) with fatty acids, fatty, alcohols, fatty amides and other fatty moieties, and with propylene oxide and polypropylene oxides. 25 Preferably the surfactant is present in the oral care composition in an amount ranging from 0.01 wt.% to 10 wt.%, more preferably from 0.1 wt.% to 8 wt.%, still more preferably from 0.021 wt.% to 5 wt.%, furthermore preferably from 2 wt.% to 4 wt.% in the composition. 30 Foaming agent: The oral care composition may preferably include one or more foaming agents to increase the amount of foam that is produced when the oral cavity is brushed. Such foaming agents are known to those of skill in the art. Illustrative examples of agents that increase the amount of foam include but are not limited to polyoxyethylene foaming agents and certain polymers 35 including, but not limited to, alginate polymers. The polyoxyethylene foaming agent may increase the amount of foam and the thickness of the foam generated by the oral care carrier P0000501 CPL 13 component of the present invention. Polyoxyethylene is also commonly known as polyethylene glycol ("PEG") or polyethylene oxide. As used herein, "polyethylene glycol" refers to a polyoxyethylene foaming agent. The amount of foaming agent in the oral care composition may be from 1 to 5 weight %; preferably from 2 to 4 weight %; preferably 3 weight %, and all ranges 5 and sub ranges there between, based on the total weight of the oral care composition. Antioxidant: The composition may further comprise an antioxidant. Any orally acceptable antioxidant can be used, including butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), vitamin A, 10 carotenoids, vitamin E, flavonoids, polyphenols, ascorbic acid, herbal antioxidants, chlorophyll, melatonin, and mixtures thereof. Colouring agent: The oral care composition may comprise at least one colorant. Colorants among those useful 15 herein include pigments, dyes, lakes, and agents imparting a particular luster or reflectivity such as pearling agents. Any orally acceptable colorant can be used, including FDIC dyes and pigments, talc, mica, magnesium carbonate, calcium carbonate, magnesium silicate, magnesium aluminum silicate, silica, titanium dioxide, zinc oxide, red, yellow, brown, and black iron oxides, ferric ammonium ferrocyanide, manganese violet, ultramarine, titaniated mica, 20 bismuth oxychloride and mixtures thereof. One or more colorants are optionally present in a total amount of 0.001 wt.% to 20 wt.%, for example about 0.01 wt.% to 10 wt.% or 0.1 wt.% to 5 wt.%. Whitening agent: 25 Preferably the composition includes a whitening agent. As used herein, the term "whitening agent" refers to a material that is effective in whitening a tooth surface to which it is applied. Preferably the whitening agent is a peroxide compound. As used herein, the term "peroxide compound" refers to an oxidizing compound comprising a bivalent oxygen-oxygen group. 30 Preferably, the peroxide compound comprises hydrogen peroxide. Preferably, the peroxide compound comprises from 0.1 wt.% to 50 wt.%, preferably from 0.1 wt.% to 40 wt.%, and more preferably from 0.1 wt.% to 30 wt.%, of the oral care composition. In further embodiments, the peroxide compound consists essentially of hydrogen peroxide. In yet other embodiments, the hydrogen peroxide delivered by the compositions of the present invention is in an amount from 35 0.1 wt.% to 3 wt.% and is preferably delivered in an amount from 01 wt.% to 2 wt.%. In further embodiments, the whitening agent comprises a solid whitening agent or a bound whitening P0000501 CPL 14 agent which is a substantially anhydrous oxygen generating compound. By way of example and not exclusion, solid whitening agents include peroxide compounds, metal chlorites, and persulfate. 5 Exemplary peroxide compounds include hydroperoxides, hydrogen peroxide, peroxides of alkali and alkaline earth metals, organic peroxy compounds, peroxy acids, pharmaceutically- acceptable salts thereof, and mixtures thereof. Peroxides of alkali and alkaline earth metals include lithium peroxide, potassium peroxide, sodium peroxide, sodium percarbonate, magnesium peroxide, calcium peroxide, barium peroxide, and mixtures thereof. Organic peroxy 10 compounds include urea peroxide, glyceryl hydrogen peroxide, alkyl hydrogen peroxides, dialkyl peroxides, alkyl peroxy acids, peroxy esters, diacyl peroxides, benzoyl peroxide, and monoperoxyphthalate, and mixtures thereof. Peroxy acids and their salts include organic peroxy acids such as alkyl peroxy acids, and monoperoxyphthalate and mixtures thereof, as well as inorganic peroxy acid salts such as and perborate salts of alkali and alkaline earth metals such 15 as lithium, potassium, sodium, magnesium, calcium and barium, and mixtures thereof. Preferred solid peroxides are sodium perborate, sodium percarbonate, urea peroxide, and mixtures thereof. Suitable metal chlorites include calcium chlorite, barium chlorite, magnesium chlorite, lithium chlorite, sodium chlorite, and potassium chlorite. The whitening agent may be bound. For example, peroxide may be bound to a polymer such as PVP (poly-N- 20 vinylpyrrolidone). Suitable PVP complexes are disclosed, for example, in U.S. Pat. No. 5,122,370, the contents of which are incorporated herein by reference in their entirety. Linear PVP peroxide and cross-linked PVP peroxide sold as Peroxydone™ from ISP Corp. are also peroxide compounds useful as whitening agents in the present invention. PVP peroxide can be effectively produced by mixing linear PVP or cross-linked PVP with concentrated liquid 25 hydrogen peroxide in the dentifrice. Preferably the bound peroxide comprises hydrogen peroxide and a polymer. Preferably the polymer comprises a porous cross-linked polymer, such as polymers of polyvinylpyrrolidone, polyacrylates, a polymethacrylates, and a polyitaconates. Preferably the peroxide compound is 30 a solid, the solid peroxide is sodium perborate or urea peroxide. Oral care composition Preferably, the oral care composition is a dentifrice. By way of example and not limitation, the term "dentifrice" as used throughout this description, denotes a paste, gel, toothpowder, dental 35 tablet, or liquid formulation. Examples of dentifrice preferably includes, deep striped, surface striped, or multilayered dentifrice and those having a gel surrounding the paste. P0000501 CPL 15 Preferably the oral care composition may include additional ingredients selected from cavity prevention, whitening, plaque prevention or reduction, gingivitis prevention or reduction, tartar control, breath malodor prevention or reduction, and stain prevention agents. 5 Preferably the oral care composition may include optional ingredients selected from flavoring agents, sweetening agents, desensitizing agents, anti-microbial agents, anti-caries agents, anti- inflammatory agents, vitamins, enzymes, preservatives, and tartar control agents, for example. pH of the oral care composition: 10 Preferably the oral care composition disclosed herein has a basic pH, such as a pH greater than 6, for example ranging from 6 to 9, or ranging from 6 to 7.5, such as a pH of about 8. It is preferred that the pH of the oral care composition may be adjusted with a base, such as sodium hydroxide or potassium hydroxide. Preferably, the pH of the oral care composition may be adjusted with sodium hydroxide. Preferably the oral care composition comprises from 0 to 15 0.05 wt.% sodium hydroxide. Flavouring agent: Optionally the oral care composition may comprise at least one flavoring agent. The at least one flavoring agent, may, for example, be selected from various flavoring aldehydes, esters, 20 alcohols, and similar materials. Examples of the flavouring oils includes spearmint, peppermint, wintergreen, sassafras, clove, sage, eucalyptus, marjoram, cinnamon, lemon, lime, grapefruit, and orange flavouring oil. Also useful are such chemicals as menthol, carvone, and anethole. Of these, the most employed are the oils of peppermint, spearmint, and wintergreen. The flavoring agent may be incorporated in the compositions disclosed herein at a concentration 25 ranging from 0.01 wt.% to 2 wt.% by weight, such as 0.1 wt.% to 1 wt.% by weight. Anti-bacterial agent: Oral care composition may preferably include an anti-bacterial agents may also be included such as Triclosan, chlorhexidine, sanguinarine extract, metronidazole. Further examples of anti-30 bacterial 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). Polymeric compounds which can enhance the delivery of active ingredients such as anti- bacterial agents can also be included. 35 P0000501 CPL 16 Other optional ingredients: 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. 5 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 10 phase. Refractive index The oral care composition according to the first aspect of the invention provides particles having a refractive index ranging from refractive index ranging from 1.4 to 1.46. Preferably the 15 refractive index is achieved by a careful management of the amount of water, refractive particles in the composition and the levels of the humectant and thickening system. The packaged product In accordance with another aspect disclosed is a packaged product comprising oral care 20 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 25 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 30 any physical means, such as a toothbrush, fingertip or by an applicator directly to the sensitive area. Method of use The composition can be effective even when used in an individual’s daily oral hygiene routine. 35 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 P0000501 CPL 17 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 5 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. Examples Example 1: 10 The composition according to the present invention as shown in table 1 were evaluated for the flavour delivery performance and the foamability according to Methods A-B. Foam measurement (Method A): The foam measurement was conducted by a cylinder shake method. The foam was read at regular intervals after 3, 6 and 12 shakes. The reading obtained 15 were recorded and provided in the table 4 below. Flavor impact (Method B): The flavor impact was studied by an expert panel and given a scoring on the scale of 1-10 with 1 being lowest perceived flavor intensity and 10 – highest perceived flavor intensity. 20 Table 1- Composition according to the invention Ingredient wt.% in the composition Demineralized water 21 Sorbitol (70% non-crystallizing grade) 35 to 70 Thickening silica 4-7.5% Abrasive silica 9.5 to 12 Anionic surfactant 2.5 to 3 Xanthan gum 0.2 to 0.4 SCMC 9H 0.5 to 0.8 Flavour 1 Others Upto 100 25 The toothpaste according to the present invention as provided in table 1 was found to provide good flavour impact and had good foamability. The foam attributes including the quantity of foam, the texture of the foam was found to be superior. The GC chromatography analysis showed that the composition according to the present invention has better flavour release. P0000501 CPL 18 Example 2: Comparative formulation A A comparative oral formulation A was prepared in accordance with Table 2 and compared with the oral composition according to the invention for foam measurement and flavor impact as given in Example 1. The results data for the comparison is provided in Tables 3-4. 5 Table 2 Ingredient Composition 1 Comparative (according to present formulation A invention) Wt% in composition wt.% in the composition Demineralized water Upto 100 Upto 100 Sorbitol (70% non-crystallizing grade) 58 58 Thickening silica 5.3 8.35 Abrasive silica 10.65 10.65 Anionic surfactant 2.7 2.7 Xanthan gum 0.25 0 SCMC 9H 0.7 0.7 Flavour 1.1 1.1 Others 1 1 10 Table 3- Experimental results for foam measurement (Method A) Foam Characteristics Composition 1 (according Comparative formulation A to present invention) Volume (in mL) - after 3 shakes 235 150 - after 6 shakes 245 195 - after 12 shakes 250 250 Table 4- Experimental results for flavor impact (Method B): 15 Attribute Composition 1 Comparative formulation (according to invention) A Average Score Average Score Overall Flavour Intensity 30sec 5.49 5.98 Overall Flavour Intensity post brushing 5.47 5.93 Cooling post brushing 7.05 7.5 Freshness post brushing 7.05 7.52 1- lowest perceived flavor intensity; 10 – highest perceived flavor intensity on the scale 1- 10 P0000501 CPL 19 As seen from above data, the composition according to the invention has better foam and flavor impact as compared to the comparative formulation A.

Claims

P0000501 CPL 20 CLAIMS 1. An oral care composition comprising: i. less than 8 wt.% thickening silica; ii. 0.1 wt. – 0.4 wt.% xanthan gum;, iii. abrasive silica; and iv. 2.5-3% an anionic and / or nonionic surfactant.

2. A composition according to claim 1, wherein the composition comprises less than 6% thickening silica.

3. A composition according to claim 1 wherein the composition comprises from 0.1 wt.% to 0.4 wt.% xanthan gum, preferably from 0.2 wt.% to 0.4 wt.% xanthan gum.

4. A composition according to claim 1 or 2 wherein the composition comprises a zinc salt selected from zinc oxide, zinc citrate, zinc sulfate, zinc chloride, zinc lactate, zinc gluconate, zinc malate, zinc tartrate, zinc carbonate, zinc phosphate and mixtures thereof, preferably the zinc salt is selected from zinc citrate trihydrate, zinc sulphate heptahydrate and mixtures thereof.

5. A composition according to any one of the preceding claims wherein the composition comprises a cellulose thickening agent, preferably a cellulose ether thickening agent.

6. A composition according to claim 5 wherein the cellulose thickening agent is carboxymethyl cellulose, preferably the carboxymethyl cellulose is present in an amount less than 1 wt.%, preferably in an amount ranging from ranging from 0.5 wt.% to 0.9 wt.%, still preferably 0.5 wt.% to 0.8 wt.%.

7. A composition according to any one of the preceding claims wherein the amount of thickening silica ranges from 0.5 to 7.5 wt.%, still preferably from 4 wt.% to 7.5 wt.% in the composition.

8. A composition according to one of the preceding claims wherein said composition comprises 10 wt.% to 70 wt% humectant, preferably 35 wt.% to 70 wt.% humectant.P0000501 CPL 21 9. A composition according to claim 8 wherein said humectant is selected from the group consisting of glycerin, sorbitol, xylitol, butylene glycol, propylene glycol and mixtures thereof, more preferably the humectant is sorbitol.

10. A composition according to any one of the preceding claims wherein the silica abrasive comprises a mixture of high abrasive silica and medium abrasive silica.

11. A composition according to any one of the preceding claims wherein the silica abrasive present in an amount ranging from 5 wt.% to 20 wt.% in the composition, preferably 5 wt.% to 12 wt.%.

12. A composition according to claim 1 wherein the anionic surfactant comprises sodium lauryl sulphate.

13. A composition according to any one of the preceding claims wherein pH of said composition is from 6 to 9 when measured using a 1 wt.% aqueous solution of said composition in distilled water at 25°C.

14. A composition according to any one of the preceding claims wherein the oral care composition comprises at least 17 wt.% of the total composition of water, more preferably at least 20 wt.% of the total composition of water.

15. A composition according to any one of the preceding claims, wherein the oral care composition has a refractive index ranging from 1.4 to 1.46.