Oral care composition

Abstract

An oral care composition comprising: a) a pigment having a hue angle, h, in the CIELAB system of from 220 to 320 degrees; b) a dye having a different colour to that of the pigment.

Description

[0001] P0001089 CPL

[0002] 1

[0003] ORAL CARE COMPOSITION

[0004] Field of the Invention

[0005] 5 The present invention relates to oral care compositions comprising pigments. The invention also relates to the use of such compositions for whitening teeth of an individual.

[0006] Background of the Invention

[0007] The enamel layer of the tooth is naturally an opaque white or slightly off-white colour. However, this enamel layer can become stained or discoloured. Many products we consume have a negative impact on our teeth and mouth. Many substances can stain or reduce the whiteness of one’s teeth, in particular, certain foods, tobacco products, and fluids such as tea and coffee. These staining and discolouring substances are often able to permeate the enamel layer. This problem occurs gradually over many years, but imparts a noticeable discoloration of the enamel

[0008] 15 of one’s teeth.

[0009] Consumers have always had a strong desire for healthy and white teeth. This desire for whiter teeth has given rise to a growing trend in the increased use of tooth whitening products which range from toothpastes to mouthwashes and chewing gums. It has been known in the literature

[0010] 20 that the whitening effect can also be produced by changing the visual perception of the color of the teeth. For example, the visual perception of a white substance can be altered through the deposition of an optical agent like pigments. However, many oral care products do not provide sufficient deposition of pigments on tooth surfaces. The pigment is simply rinsed away during daily oral hygiene routine such as tooth brushing therefore provide little or no benefits.

[0011] 25

[0012] In some instances consumers require their toothpastes to be coloured, however in some instance the colour of the toothpaste would be detrimental to the colour of the teeth.

[0013] Therefore, there is a need to develop oral care compositions which appear coloured in a shade which would be detrimental to the appearance of the teeth, yet cause the teeth to appear white. It is also desirable to have a coloured paste, that retains its original colour during use.

[0014] Summary of the Invention

[0015] In a first aspect, the present invention is directed to an oral care composition comprising:

[0016] 35 a) a pigment having a hue angle, h, in the Cl ELAB system of from 220 to 320 degrees; b) a dye having a different colour to that of the pigment. P0001089 CPL

[0017] 2

[0018] In a second aspect, the present invention is directed to a method of whitening teeth of an individual comprising the step of applying the oral care composition of any embodiment of the first aspect to at least one surface of the teeth of the individual, wherein the paste remains the same colour during use as prior to its use.

[0019] 5

[0020] All other aspects of the present invention will more readily become apparent upon considering the detailed description and examples which follow.

[0021] Detailed Description of the Invention

[0022] Except in the examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and / or use may optionally be understood as modified by the word “about”.

[0023] All amounts are by weight of the final oral care composition, unless otherwise specified.

[0024] 15 It should be noted that in specifying any ranges of values, any particular upper value can be associated with any particular lower value.

[0025] The disclosure of the invention as found herein is to be considered to cover all embodiments as found in the claims as being multiply dependent upon each other irrespective of the fact that

[0026] 20 claims may be found without multiple dependency or redundancy.

[0027] Where a feature is disclosed with respect to a particular aspect of the invention (for example a composition of the invention), such disclosure is also to be considered to apply to any other aspect of the invention (for example a method of the invention) mutatis mutandis.

[0028] 25

[0029] All amounts are by weight of the composition, unless otherwise specified.

[0030] It should be noted that in specifying any ranges of values, any upper value can be associated with any particular lower value.

[0031] Any ingredients mentioned in this application that are natural or naturally derived have been sourced from Europe.

[0032] The term “oral care composition" refers to a composition that is delivered to the oral surfaces.

[0033] 35 The composition may be a product which, during the normal course of usage, is not for the purpose of systemic administration or intentionally swallowed but is rather retained in the oral P0001089 CPL

[0034] 3 cavity for a time sufficient to contact substantially all of the dental surfaces and / or oral tissues for the purposes of oral activity.

[0035] Examples of the oral composition include a toothpaste or a dentifrice, a mouthwash or a mouth

[0036] 5 rinse, powder (e.g., tooth powder), lozenge, mint, cream, strip or gum (e.g., chewing gum), a film a topical oral gel, and a denture cleanser and the like.

[0037] The composition of the invention is used to preferably used to clean the surfaces of the oral cavity.

[0038] Accordingly, preferred product forms for compositions of the invention are those which are suitable for brushing and / or rinsing the surfaces of the oral cavity.

[0039] The composition of the invention is most preferably in the form of a dentifrice. The term

[0040] 15 "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

[0041] 20 the accessible surfaces of the oral cavity.

[0042] Preferably the dentifrice / toothpaste is in the form of an extrudable semi-solid such as a cream, paste or gel (or mixture thereof).

[0043] 25 A composition according to the invention (such as a dentifrice / toothpaste) will generally contain further ingredients to enhance performance and / or consumer acceptability, in addition to the ingredients specified above.

[0044] The composition comprises a pigment. The pigment according to the invention is a shade / material which is insoluble in the relevant medium, at the relevant temperature. This is in contrast to dyes which are soluble. The term “soluble”, as used herein, means a source that dissolves in water to give a solution with a concentration of at least 0.1 moles per litre. The term “relevant medium”, as used herein, refers to human saliva, the liquid medium in which the composition is used, at the temperature of the oral cavity during brushing of the teeth, i.e. up to

[0045] 35 37°C. The relevant medium may also be water and the relevant temperature to be 25°C. The only limitation with respect to the pigment is that the same is suitable for use in the mouth. P0001089 CPL

[0046] 4

[0047] The pigment has a hue angle, h, in the CIELAB system of from 220 to 320 degrees, more preferably from 250 to 290 degrees. A detailed description of hue angles may be found on p57 of Colour Chemistry 3rdedition by H. Zollinger published by Wiley-VCH. Preferably the pigment is violet or blue, more preferably the pigment is selected from one or more of those listed in the

[0048] 5 Colour Index International as pigment blue 1 through to pigment 83 and pigment violet 1 through to pigment violet 56. Other suitable pigments are pigment ultramarine blue and ultramarine violet. While the preferred pigment is blue or violet, the same effect may be achieved through mixing pigments outside of this hue angle range. For example, such a hue angle may also be obtained by mixing a red and green-blue pigment to yield a blue or violet shaded pigment.

[0049] It is particularly preferred that the pigment is a blue pigment. Some examples of blue pigments suitable for use in this invention include inorganic blue pigments such as iron blue (C.l. 77510) and ultramarine blue (C.l. 77007). A preferred class of blue pigments suitable for use in the

[0050] 15 invention are organic blue pigments such as phthalocyanine blue pigments. Phthalocyanines are organometallic compounds containing four symmetrically arranged isoindole rings connected in a 16-membered ring linking with alternate carbon and nitrogen atoms. Most phthalocyanines contains a central, coordinated metal ion such as copper. Copper phthalocyanines have the basis structure:

[0051] 20

[0052] Phthalocyanine blue pigments exhibit more than one crystal modification, which differ in terms of coloristics. Methods have been developed to phase-stabilise the phthalocyanine pigment

[0053] 25 molecule in order to prevent conversion to a different crystal modification. An example is minor chemical modification of the molecule, for instance partial chlorination. Methods have also been developed to stabilise the phthalocyanine pigment molecule against flocculation during pigment application. An example is admixture of other agents to the molecule, such as surface active additives to the pigment molecule. The following pigments are illustrative phthalocyanine blue

[0054] 30 pigments preferably included in the composition according to the invention: P0001089 CPL

[0055] 5

[0056] It is especially preferred that the pigment is phthalocyanine blue pigment selected from alpha copper phthalocyanines Pigment Blue 15, Pigment Blue 15:1, Pigment 15:2 and mixtures

[0057] 5 thereof. Most preferably the pigment is Pigment Blue 15:1. A commercially available example is Cosmenyl Blue A4R from Clariant.

[0058] The pigment suitable for use in this invention may also be mixtures of any of the above described materials.

[0059] The oral care composition of the present invention may comprise other pigments in addition to those described above which are included in the composition. It is preferred that the other pigments are green pigments, more preferably green pigments having a hue angle from 120 to 200 degrees. The preferred green pigment is phthalocyanine green pigment, more preferably

[0060] 15 Phthalocyanine Green CI-74260. When included, it is preferred that the composition comprises a combination of green and blue pigments. The weight ratio of green pigment to blue pigment is greater than 1 :2, preferably greater than 2:3, more preferably from 2:3 to 3:2.

[0061] The oral care composition of the present invention typically comprises from 0.01 to 10.5wt% of the total composition of pigment, more preferably from 0.02 to 0.3wt%, and most preferably from 0.04 to 0.2wt%.

[0062] Compositions according to the invention comprise a dye, preferably the dye is red, more preferably it as an azo dye. Particularly preferred is Acid Red 33 (Cl 17200. It is preferred if the

[0063] 25 total level of dye is from 0.01 to 0.2 wt% of the total composition, preferably 0.02 to 0.1 wt%.

[0064] Preferably the weight ration of dye to pigment is from 2:1 to 1:10, more preferably from 1 :1 to P0001089 CPL

[0065] 6

[0066] In one preferred embodiment the toothpaste appears purple or at least one phase within the phase is purple. This colouring is due to the inclusion of a blue pigment and a red dye.

[0067] Preferably the toothpaste has one continuous phase, more preferabley the composition has one

[0068] 5 homogenous colour.

[0069] In the event the composition has more than one phase the pigment and dye are preferably in the same phase, more preferably the pigment and dye are mixed to form a homogenous colour.

[0070] Compositions according to the invention, particularly toothpastes, comprise particulate abrasive materials such as silicas, aluminas, calcium carbonates, dicalciumphosphates, calcium pyrophosphates, hydroxyapatites, trimetaphosphates, insoluble hexametaphosphates and so on, including agglomerated particulate abrasive materials, usually in amounts between 3 and 60% by weight of the oral care composition.

[0071] 15

[0072] In one embodiment of the invention the composition comprises a silica based abrasive. In terms of the present application the thickening silica preferably has an abrasivity (RDA) of greater than 60, more preferably greater than 100. The preferred abrasive silicas used in the present invention is a silica with a low refractive index. It may be used as the sole abrasive

[0073] 20 silica, or in conjunction with a low level of other abrasive silicas, e.g. those according to EP 236070. The low refractive index silicas, used as abrasives in the present invention are preferably silicas with an apparent refractive index (R.l.) in the range of 1.41 - 1.47, preferably 1.435 - 1.445, preferably having a weight mean particle size of between 5 and 15 pm, a BET (nitrogen) surface area of between 10 and 100 m2 / g and an oil absorption of about 70 - 150

[0074] 25 cm3 / 100 g, but abrasive silicas with a lower apparent refractive index may also be used. Typical examples of suitable low refractive index abrasive silicas (e.g. having an R.l. of between 1.435 and 1.445) are Tixosil 63 and 73 ex Rhone Poulenc; Sident 10 ex Degussa; Zeodent 113 ex Zeofinn; Zeodent 124 ex Evonik, Sorbosil AC 77 ex PQ Corporation (having an R.l. of approximately 1.440). The amount of these silicas in the composition generally ranges from 5-60% by weight, usually 5-20% by weight.

[0075] An alternative suitable abrasive is calcium carbonate. Natural calcium carbonate abrasive is typically a finely ground limestone which may optionally be refined or partially refined to remove impurities. The material preferably has an average particle size of less than 10 microns, e.g.,

[0076] 35 3-7 microns, e.g., about 5.5 microns. For example, a small particle silica may have an average particle size (D50) of 2.5 -4.5 microns. Because natural calcium carbonate may contain a high P0001089 CPL

[0077] 7 proportion of relatively large particles of not carefully controlled, which may unacceptably increase the abrasivity, preferably no more than 0.01 wt%, preferably no more than 0.004 percent by weight of particles would not pass through a 325 mesh. The material has strong crystal structure, and is thus much harder and more abrasive than precipitated calcium

[0078] 5 carbonate. The tapped density for the natural calcium carbonate is for example between 1 and 1.5 g / cc, e.g., about 1.2 for example about 1.19 g / cc. There are different polymorphs of natural calcium carbonate, e.g., calcite, aragonite and vaterite, calcite being preferred for purposes of this invention.

[0079] Compositions according to invention preferably comprise surfactants, such as anionic, nonionic, cationic and zwitterionic or amphoteric surfactants. Anionic surfactants are preferred, particularly preferred is sodium lauryl sulfate. If present it is preferable that the total level of surfactant is from 0.5 to 5 wt% of the total composition.

[0080] 15 Precipitated calcium carbonate has a different crystal structure from natural calcium carbonate. It is generally more friable and more porous, thus having lower abrasivity and higher water absorption. For use in the present invention, the particles are small, e.g., having an average particle size of 1-5 microns, and e.g., no more than 0.1 percent, preferably no more than 0.05 percent by weight of particles which would not pass through a 325 mesh. The particles

[0081] 20 may for example have a D50 of 3-6 microns, for example 3.8-4.9, e.g., about 4.3; a D50 of 1-4 microns, e.g., 2.2-2.6 microns, e.g., about 2.4 microns, and a D10 of 1-2 microns, e.g., 1.2- 1.4, e.g., about 1.3 microns. The particles have relatively high water absorption, e.g., at least 25 g / 100 g, e.g., 30-70 g / 100 g.

[0082] 25 In some embodiments, additional calcium-containing abrasives, for example calcium phosphate abrasive, e.g., tricalcium phosphate, hydroxyapatite or dicalcium phosphate dihydrate or calcium pyrophosphate, and / or silica abrasives, sodium metaphosphate, potassium metaphosphate, aluminum silicate, calcined alumina, or other siliceous materials, or combinations thereof are used.

[0083] The composition, particularly if a toothpaste preferably comprises an inorganic or a natural or synthetic thickener or gelling agent in proportions of about 0.10 to about 15% by weight depending on the material chosen. These proportions of thickeners in the dentifrice compositions of the present invention form an extrudable, shape-retaining product which can be

[0084] 35 squeezed from a tube onto a toothbrush and will not fall between the bristles of the brush but rather, will substantially maintain its shape thereon. Suitable thickeners or gelling agents useful P0001089 CPL

[0085] 8 in the practice of the present invention include inorganic thickening silicas such as amorphous silicas available from Huber Corporation under the trade designation Zeodent 165, Irish moss, iota-carrageenan, gum tragacanth, and polyvinylpyrrolidone.

[0086] 5 Further suitable binders and thickeners can be present and include as sodium carboxymethylcellulose, hydroxyethyl cellulose (Natrosol®), xanthan gum, gum arabic etc. as well as synthetic polymers such as polyacrylates and carboxyvinyl polymers such as Carbopol®.

[0087] Compositions according to the invention may comprise a polymeric deposition aid. Preferably the composition comprises acid anhydride polymers, particularly preferred are co-polymers of maleic anhydride with methyl vinylether, in which the anhydride moiety may be in a partially or fully hydrolysed or alcoholysed form. Preferred copolymers include Gantrez(R) polymers such as:

[0088] Gantrez S-95: molecular weight 216,000; free acid;

[0089] 15 Gantrez S-96: molecular weight 700,000; free acid;

[0090] Gantrez S-97: molecular weight 1 ,500,000; free acid; and

[0091] Gantrez MS-955: molecular weight 1,060,000; calcium / sodium salt.

[0092] Particularly preferred co-polymers of maleic acid and methyl vinylether have a molecular weight of 1 ,000,000 or greater and an especially preferred material is Gantrez S-97.

[0093] 20

[0094] If the composition is a toothpaste it may be a multi phase paste having different colours for each phase.

[0095] Compositions according to the invention may comprise water-soluble or sparingly water-soluble

[0096] 25 sources of metal salts Preferred are zinc ions such as zinc chloride, zinc acetate, zinc gluconate, zinc sulphate, zinc fluoride, zinc citrate, zinc lactate, zinc oxide, zinc monoglycerolate, zinc tartrate, zinc pyrophosphate and zinc maleate; also preferred are stannous ions such as stannous fluoride and stannous chloride.

[0097] Compositions according to the invention may comprise oral care enzyme systems such as hydrogen peroxide producing enzyme systems (e.g. the oxidoreductase enzyme glucose oxidase), amyloglucosidase, dextranase and / or mutanase, (optionally in the presence of zinc ion providing compounds and / or 8- hydroxyquinoline derivatives), lactoperoxidase, lactoferrin, lysozyme and mixtures thereof.

[0098] 35 P0001089 CPL

[0099] 9

[0100] Compositions of the invention may comprises fluoride sources such as sodium fluoride, stannous fluoride, sodium monofluorophosphate, zinc ammonium fluoride, tin ammonium fluoride, calcium fluoride, cobalt ammonium fluoride and mixtures thereof. Fluoride ion sources may be added to the compositions at a level of about 0.001 wt. percent to about 10 wt. percent,

[0101] 5 e.g., from about 0.003 wt. percent to about 5 wt. percent, 0.01 wt. percent to about 1 wt., or about 0.05 wt. percent. In some embodiment, the stannous fluoride is present in an amount of 0.1 wt. percent to 2 wt. percent (0.1 wt percent -0.6 wt. percent) of the total composition weight. Fluoride ion sources may be added to the compositions at a level of about 0.001 wt. percent to about 10 wt. percent, e.g., from about 0.003 wt. percent to about 5 wt. percent, 0.01 wt. percent to about 1 wt., or about 0.05 wt. percent. 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. In some embodiment, the fluoride source is a fluoride salt present in an amount of 0.1 wt. percent to 2 wt. percent (0.1 wt percent -0.6 wt. percent) of the total composition weight

[0102] 15 (e.g., sodium fluoride (e.g., about 0.32 wt. percent).

[0103] Some embodiments of the invention are free from fluoride sources, that is the composition comprises less than 0.01 wt% of a fluoride source.

[0104] 20 In one embodiment a preferred class of oral care active for inclusion in the compositions of the invention includes agents for the remineralisation of teeth. The term “remineralisation” in the context of the present invention means the in situ generation of hydroxyapatite on teeth.

[0105] A specific example of a suitable agent for the remineralisation of teeth is a mixture of a calcium

[0106] 25 source and a phosphate source which, when delivered to the teeth results in the in situ generation of hydroxyapatite on teeth.

[0107] Illustrative examples of the types of calcium source that may be used in this context (hereinafter termed “remineralising calcium sources”) include, for example, calcium phosphate, calcium

[0108] 30 gluconate, calcium oxide, calcium lactate, calcium glycerophosphate, calcium carbonate, calcium hydroxide, calcium sulphate, calcium carboxymethyl cellulose, calcium alginate, calcium salts of citric acid, calcium silicate and mixtures thereof. Preferably the remineralising calcium source is calcium silicate. P0001089 CPL

[0109] 10

[0110] Calcium salts, particularly calcium carbonate can also be used for enamel remineralization. Preferred calcium carbonate has a particle size (D50)) from 0.1 to 3 microns, preferable from 0.5 to 2 microns, more preferably from 0.6 to 1.8 microns.

[0111] 5 The amount of remineralising calcium source(s) (e.g. calcium silicate) in the composition of the invention typically ranges from 1 to 30%, preferably from 5 to 20% by total weight remineralising calcium source based on the total weight of the oral care composition.

[0112] Illustrative examples of the types of phosphate source that may be used in this context (hereinafter termed “remineralising phosphate sources”) include, for example, monosodium dihydrogen phosphate, disodium hydrogen phosphate, sodium pyrophosphate, tetrasodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, potassium dihydrogenphosphate, trisodium phosphate, tripotassium phosphate and mixtures thereof. Preferably the remineralising phosphate source is a mixture of trisodium phosphate and sodium

[0113] 15 dihydrogen phosphate.

[0114] The amount of remineralising phosphate source(s) (e.g. trisodium phosphate and sodium dihydrogen phosphate) in the composition of this invention typically ranges from 2 to 15%, preferably from 4 to 10% by total weight remineralising phosphate source based on the total

[0115] 20 weight of the oral care composition.

[0116] In some embodiments, the oral care compositions comprise an effective amount of one or more antibacterial agents, for example comprising an antibacterial agent selected from halogenated diphenyl ether (e.g. triclosan), triclosan monophosphate, herbal extracts and essential oils (e.g.,

[0117] 25 rosemary extract, tea extract, magnolia extract, thymol, menthol, eucalyptol, geraniol, carvacrol, citral, hinokitol, magnolol, ursolic acid, ursic acid, catechol, methyl salicylate, epigallocatechin gallate, epigallocatechin, gallic acid, miswak extract, sea-buckthorn extract), bisguanide antiseptics (e.g., chlorhexidine, alexidine or octenidine), quaternary ammonium compounds (e.g., cetylpyridinium chloride (CPC), CPC-claybenzalkonium chloride, tetradecylpyridinium chloride (TPC), N-tetradecyl-4-ethylpyridinium chloride (TDEPC)), phenolic antiseptics, hexetidine furanones, bacteriocins, ethyllauroyl arginate, arginine bicarbonate, a Camellia extract, a flavonoid, a flavan, halogenated diphenyl ether, creatine, sanguinarine, povidone iodine, delmopinol, salifluor, metal ions (e.g., zinc salts, stannous salts, copper salts, iron salts), propolis and oxygenating agents (e.g., hydrogen peroxide, buffered sodium peroxyborate or

[0118] 35 peroxycarbonate), phthalic acid and its salts, monoperthalic acid and its salts and esters, ascorbyl stearate, oleoyl sarcosine, alkyl sulfate, dioctyl sulfosuccinate, salicylanilide, domiphen P0001089 CPL

[0119] 11 bromide, delmopinol, octapinol and other piperidino derivatives, nisin preparations, chlorite salts; parabens such as methylparaben or propylparaben and mixtures of any of the foregoing. One or more additional antibacterial or preservative agents may optionally be present in the composition in a total amount of from about 0.01 wt. percent to about 0.5 wt. percent, optionally

[0120] 5 about 0.05 wt. percent to about 0.1 wt. percent or about 0.3 percent, by total weight of the composition.

[0121] In some embodiments, the oral care compositions also comprise at least one flavorant, useful for example to enhance taste of the composition. Any orally acceptable natural or synthetic flavorant can be used, including without limitation essential oils and various flavoring aldehydes, esters, alcohols, and similar materials, tea flavors, vanillin, sage, marjoram, parsley oil, spearmint oil, cinnamon oil, oil of Wintergreen, peppermint oil, clove oil, bay oil, anise oil, eucalyptus oil, citrus oils, fruit oils, sassafras and essences including those derived from lemon, orange, lime, grapefruit, apricot, banana, grape, apple, strawberry, cherry, pineapple, etc.,

[0122] 15 bean-and nut-derived flavors such as coffee, cocoa, cola, peanut, almond, etc., adsorbed and encapsulated flavorants and the like. Also encompassed within flavorants herein are ingredients that provide fragrance and / or other sensory effect in the mouth, including cooling or warming effects. Such ingredients illustratively include menthol, carvone, menthyl acetate, menthyl lactate, camphor, eucalyptus oil, eucalyptol, anethole, eugenol, cassia, oxanone, a-irisone, ,

[0123] 20 thymol, linalool, benzaldehyde, cinnamaldehyde, N-ethyl-p-menthan-3-carboxamine, N, 2, 3- trimethyl-2- isopropylbutanamide, 3- (1-menthoxy) -propane-1, 2-diol, cinnamaldehyde glycerol acetal (CGA), menthone glycerol acetal (MGA) and the like. One or more flavorants are optionally present in a total amount of from about 0.01 wt. percent to about 5 wt. percent, for example, from about 0.03 wt. percent to about 2.5 wt. percent, optionally about 0.05 wt. percent

[0124] 25 to about 1.5 wt. percent, further optionally about 0.1 wt. percent to about 0.3 wt. percent and in some embodiments in various embodiments from about 0.01 wt. percent to about 1 wt. percent, from about 0.05 to about 2 percent, from about 0.1 percent to about 2.5 percent, and from about 0.1 to about 0.5 percent by total weight of the composition.

[0125] In some embodiments, the oral care compositions comprise at least one sweetener, useful for example to enhance taste of the composition. Sweetening agents among those useful herein include dextrose, polydextrose, sucrose, maltose, dextrin, dried invert sugar, mannose, xylose, ribose, fructose, levulose, galactose, corn syrup, partially hydrolyzed starch, hydrogenated starch hydrolysate, ethanol, sorbitol, mannitol, xylitol, maltitol, isomalt, aspartame, neotame,

[0126] 35 saccharin and salts thereof (e.g. sodium saccharin), sucralose, dipeptide-based intense sweeteners, cyclamates, dihydrochalcones. P0001089 CPL

[0127] 12

[0128] One or more sweeteners are optionally present in a total amount depending strongly on the particular sweetener (s) selected, but typically 0.005 wt. percent to 5 wt. percent, by total weight of the composition, optionally 0.005 wt. percent to 0.2 wt. percent, further optionally 0.05 wt. percent to 0.1 wt. percent by total weight of the composition.

[0129] 5

[0130] In some embodiments, the oral care compositions further comprise an agent that interferes with or prevents bacterial attachment, e.g., ethyl lauroyl arginiate (ELA), solbrol or chitosan, as well as plaque dispersing agents such as enzymes (papain, glucoamylase, etc.).

[0131] Mixtures of any of the above described materials may also be used.

[0132] The composition according the invention will comprise further ingredients which are common in the art, such as: antimicrobial agents, e.g. chlorhexidine, sanguinarine extract, metronidazole, quaternary

[0133] 15 ammonium compounds, such as cetylpyridinium chloride; cetylpyridium chloride clay complex bis-guanides, such as chlorhexidine digluconate, hexetidine, octenidine, alexidine; and halogenated bisphenolic compounds, such as 2,2' methylenebis-(4-chloro-6-bromophenol); anti-inflammatory agents such as ibuprofen, flurbiprofen, aspirin, indomethacin etc.; anti-caries agents such as sodium- and stannous fluoride, aminefluorides, sodium

[0134] 20 monofluorophosphate, sodium trimeta phosphate and casein; plaque buffers such as urea, calcium lactate, calcium glycerophosphate and strontium polyacrylates; vitamins such as Vitamins A, C, D, B (preferably B3) and E; plant extracts;

[0135] 25 plant-derivable antioxidants such as flavonoid, catechin, polyphenol, and tannin compounds and mixtures thereof; desensitising agents, e.g. potassium citrate, potassium chloride, potassium tartrate, potassium bicarbonate, potassium oxalate, potassium nitrate and strontium salts; anti-calculus agents, e.g. alkali-metal pyrophosphates, hypophosphite-containing polymers, organic phosphonates and phosphocitrates etc.; biomolecules, e.g. bacteriocins, antibodies, enzymes, etc.; flavours, e.g. peppermint and spearmint oils; proteinaceous materials such as collagen; preservatives;

[0136] 35 opacifying agents; hyaluronic acid; P0001089 CPL

[0137] 13 amino acids such as arginine; colouring agents; pH-adjusting agents; sweetening agents;

[0138] 5 mouth feel agents pharmaceutically acceptable carriers, e.g. starch, sucrose, water or water / alcohol systems etc.; Humectants such as glycerol, sorbitol, propyleneglycol, xylitol, lactitol etc.; polymeric compounds which can enhance the delivery of active ingredients such as antimicrobial agents can also be included;

[0139] 10 buffers and salts to buffer the pH and ionic strength of the oral care composition; and other optional ingredients that may be included are e.g. bleaching agents such as peroxy compounds e.g. potassium peroxydiphosphate, effervescing systems such as sodium bicarbonate / citric acid systems, colour change systems, and so on.

[0140] Examples were prepared according to the table below and were used to whiten teeth as follows. Extracted human incisors and premolars were cleaned with a white toothpaste and placed in sterile saliva for two hours. After rinsing with water, baseline tooth colour was measured using a colorimeter. Tooth specimens were then brushed with a water: toothpaste slurry (2:1) of the test

[0141] 20 toothpastes for 60 seconds with a toothbrush, rinsed with water and their colour remeasured. Changes in tooth colour were calculated using the WIO tooth whiteness index.

[0142] P0001089 CPL

[0143] 14

[0144] Table 1

[0145] 5 Example 1 is purple in colour yet whitens the tooth to a level that is equivalent to a toothpaste that is blue in colour.

[0146] The paste remains purple during use.

[0147] 10

Claims

P0001089 CPL15CLAIMS1. An oral care composition having one phase and comprising: a) a pigment having a hue angle, h, in the Cl ELAB system of from 220 to 320 degrees; b) a dye having a different colour to that of the pigment.

2. An oral care composition according to claim 1 in which the pigment and dye are in the same phase.

3. An oral care composition according to any preceding claim having one homogenous colour.

4. An oral care composition according to any preceding claim in which the dye is a red dye.

5. An oral care composition according to any of the preceding claims, wherein the pigment has a hue angle, h, in the Cl ELAB system of from 250 to 290.

6. An oral care composition according to any of the preceding claims, wherein the pigment is a blue pigment, preferably a phthalocyanine blue pigment.

7. An oral care composition according to claim 6, wherein the phthalocyanine blue pigment is selected from alpha copper phthalocyanines Pigment Blue 15, Pigment Blue 15:1, Pigment Blue 15:2 and mixtures thereof, preferably Pigment Blue 15:1.

8. An oral care composition according to any of the preceding claims, wherein the composition further comprises green pigments, preferably phthalocyanine green pigment.

9. An oral composition according to any preceding claim in which the total level of pigment is from 0.02 to 0.3 wt% of the total composition, preferably 0.04 to 0.2 wt%.

10. An oral care composition according to any preceding claim in which the total level of dye is from 0.01 to 0.2 wt% of the total composition, preferably 0.02 to 0.1 wt%.

11. An oral care composition according to any preceding claim in which the weight ratio of dye to pigment is from 2:1 to 1:10, preferably from 1 :1 to 1:5.P0001089 CPL1612. An oral care composition according to any preceding claim that is a toothpaste.

13. An oral acre composition according to any preceding claim which further comprises a silica abrasive.

14. An oral care composition according to any preceding claims, wherein the composition further comprises an anionic surfactant, preferably sodium lauryl sulfate.

15. An oral care composition according to any preceding claims, wherein the composition is an aqueous composition.

16. A method of whitening teeth of an individual comprising the steps of applying the composition according to any of the preceding claims to at least one surface of the teeth of an individual, wherein the paste remains the same colour during use as prior to its use.

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