Oral compositions forming a coacervate gel

Abstract: The present invention relates to a dentifrice formulation comprising first and second dentifrice compositions and to a dentifrice formulation that is a single dentifrice composition. The first dentifrice composition or the single dentifrice composition will comprise from 0.1% to 10% of a surfactant selected from anionic surfactants, cationic surfactants, amphoteric surfactants, and mixtures thereof; from 0.1% to 10% of a charged polymer; and from 80% to 99% of one or more aqueous carriers; wherein the charged polymer is diluted to form a charged polymer slurry and the pH of the charged polymer slurry is from 1.5 to 10, the charged polymer slurry is combined with the anionic, cationic, or amphoteric surfactant to form a coacervate gel, and the coacervate gel is then combined with the one or more aqueous carriers to form the dentifrice composition. The present invention also relates to a method of making a dentifrice composition containing a coacervate gel, comprising the steps of diluting from 0.1% to 10% of a charged polymer to form a charged polymer slurry, the charged polymer slurry having a pH of from 1.5 to 10; combining the charged polymer slurry with from 0.1% to 10% of a surfactant selected from anionic surfactants, cationic surfactants, amphoteric surfactants, and mixtures thereof, to form a coacervate gel; and combining the coacervate gel with from 80% to 99% of one or more aqueous carriers to form the dentifrice composition.

Description: BACKGROUND OF THE INVENTION The present invention relates to dentifrice formulations which contain a coacervate gel. The coacervate gel is formed by combining an anionic, cationic, and/or amphoteric surfactant with a charged polymer. The coacervate gel is then combined with the additional carrier materials to form the dentifrice composition. The dentifrice formulation may contain two separate dentifrice compositions or a single dentifrice composition. Coacervate gels are known in the art. Coacervate gels are commonly formed in shampoos and other soaps. Coacervate gels are used to deposit active substances on a target surface. Examples include U.S. Patent 5,476,660, to Somasundaran et al., issued December 19, 1995. Coacervate gels are also used to form microcapsules. Typically, the microcapsule will comprise perfumes, silica, or other substances to be deposited. An example of a microcapsule formed by a coacervate gel includes U.S. Patent 5,126,061, issued June 30, 1992, to Michael. In the present invention, a coacervate gel is formed but it is not used to microencapsulate a substance. Also known in the art are the polymers used to form the coacervate gels. Although these polymers are used in dentifrices, the polymer used are neutralized and do not remain charged. For example, U.S. Patent 4,988,500 to Hunter et al., issued January 29, 1991, describes the use of a carboxyvinyl polymer in a dentifrice. EP-A-202, 359 discloses a dental preparation in which an acrylic polymer may be combined with an anionic or nonionic surfactant but does not disclose the combination of the polymer with amphoteric or cabonic surfactant GB-A-1,271,944 also discloses carboxyvinyl polymers in combination with anionic surfactants. Whilst EP-A-249,348 also discloses oral compositions which optionally compnse amphoteric or cationic surfactants and further includes examples which comprise a carboxyvinyl polymer, it neither discloses their specific combination nor the conditions which would be necessary in order to form a coacervate gel from their combination. In the present invention, the polymer will remain charged to form a coacervate gel with the surfactant. It is known that dentifrice aesthetics can be improved by optimizing the foaming and product consistency. The present inventor has discovered that a dentifrice with improved sensory attributes can be made by forming a coacervate gel. By forming a coacervate gel in the dentifrice composition, the dentifrice and foam have a creamier consistency and a slick, smooth teeth feeling is achieved. Additionally, the dentifrice may also provide a longer lasting flavor. Therefore, it is an object of the present invention to provide stable dentifrice formulations comprising a coacervate gel. The dentifrice formulation may be a single composition with a coacervate gel or a dual phase composition in which one or both dentifrice compositions comprise a coacervate gel. It is also an object of the present invention to provide a method of making a dentifrice formulation with a coacervate gel. These and other objects of the present invention will become readily apparent from the detailed description which follows. All percentages and ratios used herein are by weight of the specific dentifrice composition and not of the overall dentifrice formulation that is delivered, unless otherwise specified. All measurements are made at 25° C, unless otherwise specified. SUMMARY OF THE INVENTION The present invention relates to a dentifrice formulation comprising first and second dentifrice compositions and to a dentifrice formulation that is a single dentifrice composition. The first dentifrice composition or the single dentifrice composition will comprise from 0.1% to 10% of a surfactant from 0.1% to 10% of a charged polymer; and from 80% to 99% of one or more aqueous carriers; as set out in claim 1. The present invention also relates to methods of making the dentifrice composition containing a coacervate gel, comprising the steps of diluting from 0.1% to 10% of a charged polymer to form a charged polymer slurry, having a pH of from 1.5 to 10; combining the charged polymer slurry with a surfactant having an opposite charge to form a coacervate gel; and optionally adjusting the pH. DETAILED DESCRIPTION OF THE INVENTION The dentifrice formulation of the present invention may be in the form of a toothpaste or dentifrice. The term "dentifrice formulation" as used herein means the total dentifrice that is delivered to the oral surfaces. The dentifrice formulation may be a combination of the two or more dentifrice compositions or may be a single dentifrice composition. The dentifrice formulation is a product, which in the ordinary course of usage, is not intentionally swallowed for purposes of systemic administration of particular therapeutic agents, but is rather retained in the oral cavity for a time sufficient to contact substantially all of the dental surfaces and/or oral tissues for purposes of oral activity. The term "dentifrice", as used herein, means paste, gel, or liquid formulations unless otherwise specified. The dentifrice composition may be in any desired form, such as deep striped, surface striped, multilayered, having the gel surrounding the paste, or any combination thereof. The dentifrice composition may be contained in a physically separated compartment of a dispenser and dispensed side-by-side or may be a single composition. The term "dispenser", as used herein, means any pump, tube, or container suitable for dispensing dentifrice. The term "aqueous carrier" as used herein means any safe and effective materials for use in the compositions of the present invention. Such materials include alkali metal bicarbonate salts, calcium peroxide, abrasive polishing materials, propylene glycol, acidic compounds, buffering agents, polyoxyethylene, thickening materials, humectants, water, surfactants, titanium dioxide, flavor system, coolants, sweetening agents, xylitol, coloring agents, antimicrobial agents, and mixtures thereof. The present compositions comprise essential components, as well as optional components. The essential and optional components of the compositions of the present invention are described in the following paragraphs. Surfactants Anionic, cationic, and/or amphoteric surfactants are required in the present invention. Suitable surfactants, commonly referred to as sudsing agents, are those which are reasonably stable and foam through a wide pH range. 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. Other suitable anionic surfactants are sarcosinates, such as sodium lauroyl sarcosinate, taurates, sodium lauryl sulfoacetate, sodium lauroyl isethionate, sodium laureth carboxylate, and sodium dodecyl benzenesulfonate. Preferred cationic surfactants useful in the present invention can be broadly defined as derivatives of aliphatic quaternary ammonium compounds having one long alkyl chain containing from 8 to 18 carbon atoms. Suitable cationic surfactants include ethoxylated fatty amines, fatty ammonium chlorides, fatty pyridinium chlorides, fatty dimethylamines, fatty dimethylamine lactates, and mixture thereof. Specific cationic surfactants include lauryl trimethylammonium chloride, cetyl pyridinium chloride, cetyl trimethylammonium bromide, di-isobutylphenoxyethyl-dimethylbenzylammonium chloride, coconut alkyltrimethylammonium nitrite, and cetyl pyridinium fluoride. The quaternary ammonium fluorides are described in U.S. Patent 3,535,421, October 20, 1970, to Briner et al. Certain cationic surfactants, such as chlorhexidine, can also act as antimicrobials in the compositions. The amphoteric surfactants useful in the present invention can be broadly described as derivatives of aliphatic secondary and tertiary amines in which the aliphatic radical can be a straight chain or branched and wherein one of the aliphatic substituents contains from 8 to 18 carbon atoms and one contains an anionic water-solubilizing group, e.g., carboxylate, sulfonate, sulfate, phosphate, or phosphonate. Other suitable amphoteric surfactants are betaines, specifically cocamidopropyl betaine. Mixtures of amphoteric surfactants can also be employed, as well as mixtures of anionic, cationic, and/or amphoteric surfactants. Many surfactants suitable for use are disclosed by Gieske et al., U.S. Patent 4,051,234, issued September 27, 1977. The present composition comprises one or more surfactants at a level of from 0.1% to 10%, preferably from 0.2% to 8%, and most preferably from 0.25% to 6%, by weight of the composition. Charged Polymer The dentifrice composition of the present invention also comprises a charged polymer. The charged polymer will be anionic or cationic. Preferably, the charge of the polymer should be opposite the charge of the surfactant if an amphoteric surfactant is not present by itself or in combination with another surfactant. For example, if the charged polymer is anionic, the surfactants may be amphoteric; cationic; amphoteric and cationic; amphoteric and anionic; or amphoteric, anionic, and cationic. Suitable cationic polymers include cationically modified guar gum, polyquaternary amines, and polyacrylamides. Suitable anionic polymers include polyacrylic acids, polyvinyl acetates, polymaleic acid, polycarbonates, polysulfonates, and mixtures thereof. Additional anionic polymeric polycarboxylates, such as Gantrez, are described in U.S. Patent 5,0376,37 to Gaffar et al, issued August 6, 1991. The preferred anionic polymer is a carboxyvinyl polymer. Carboxyvinyl polymers are described in U.S. Patent 2,798,053 to Brown, issued July 2, 1957. Carboxyvinyl polymers are provided by B.F. Goodrich Company as Carbopol 934, 940, 941, 946, and 956. Mixtures of charged polymers can also be employed. The present composition comprises a charged polymer at a level of from 0.1% to 10%, preferably from 0.2% to 8%, and most preferably from 0.25% to 6%, by weight of the dentifrice composition. Coacervate Gel Coacervate formation is dependent upon a variety of criteria such as molecular weight, component concentration, and ratio of interacting ionic components, ionic strength (including modification of ionic strength, for example, by addition of salts), charge density of the cationic and anionic components, pH, and temperature. Coacervate systems and the effect of these parameters have been described, for example, by J. Caelles, et al., "Anionic and Cationic Compounds in Mixed Systems", Cosmetics & Toiletries, Vol. 106, April 1991, pp 49-54, C. J. van Oss, "Coacervation, Complex-Coacervation and Flocculation", J. Dispersion Science and Technology, Vol. 9 (5,6), 1988-89, pp 561-573, and D. J. Burgess, "Practical Analysis of Complex Coacervate Systems", J. of Colloid and Interface Science, Vol. 140, No. 1, November 1990, pp 227-238. The coacervate gel of the present invention comprises anionic, cationic, and/or amphoteric surfactants and a charged polymer. The coacervate gel is formed by combining the charger polymer with the surfactant. Preferably, the charged polymer is contained in a slurry. The charged polymer slurry will have a pH of from 1.5 to 10. An anionic polymer slurry will have a pH of from 1.5 to 7 and preferably from 1.5 to 4.5. A cationic polymer slurry will have a pH of from 7 to 10 and preferably from 7.5 to 9. The slurry may comprise humectants and/or water. Preferred humectants include glycerin and sorbitol. The ratio of charged polymer to humectant is from 1:20 to 1:100, preferably from 1:30 to 1:60. The charged polymer slurry is then combined with the surfactant. This forms the coacervate gel. A coacervate gel formed by an anionic polymer will have a pH of from 3 to 7, preferably from 4.5 to 6.5, and more preferably from 4.5 to 6.0. A coacervate gel formed by a cationic surfactant will have a pH of from 7 to 9 and preferably from 8 to 8.5. After the coacervate gel is formed, it may be neutralized with a buffering agent to form the dentifrice composition. The final pH of the dentifrice composition will be from 4 to 8.5. The final pH of a dentifrice composition containing a coacervate gel made with an anionic polymer will be from 5 to 6. The coacervate gel may additionally comprise a flavor system or other hydrophobic species. If a hydrophobic species is present, it will be emulsified with the surfactant. The emulsified surfactant and hydrophobic species will then be added to the charged polymer slurry to form the coacervate gel. Fluoride Ion Source The first and/or second dentifrice compositions or the single dentifrice composition of the present invention may incorporate a soluble fluoride ion source capable of providing free fluoride ions. Preferred soluble fluoride ion sources include sodium fluoride, stannous fluoride, indium fluoride, and sodium monofluorophosphate. Sodium fluoride is the most preferred soluble fluoride ion source. Norris et al., U.S. Patent 2,946,725, issued July 26, 1960, and Widder et al., U.S. Patent 3,678,154 issued July 18, 1972, disclose such fluoride ion sources as well as others. The fluoride ion source should be capable of providing from 50 ppm to 3500 ppm, and preferably from 500 ppm to 3000 ppm of free fluoride ions. Tartar Control Agents The present invention may include a tartar control agent. The tartar control agent may be present in the first or second dentifrice compositions, both compositions, or in the single dentifrice composition. The tartar control agent may be any materials known to be effective in reducing calcium phosphate mineral deposition related to calculus formation. The preferred tartar control agent is selected from a polyphosphate source, including a tripolyphosphate source, pyrophosphate salts, and mixtures thereof. The pyrophosphate salts useful in the present compositions include the di and tetra alkali metal pyrophosphate salts, and mixtures thereof. Disodium dihydrogen pyrophosphate (Na 2 H 2 P 2 O 7 ), tetrasodium pyrophosphate (Na 4 P 2 O 7 ), and tetrapotassium pyrophosphate (K 4 P 2 O 7 ) in their unhydrated as well as hydrated forms are the preferred species. In compositions of the present invention, the pyrophosphate salt may be present in one of three ways: predominately dissolved, predominately undissolved, or a mixture of dissolved and undissolved pyrophosphate. Compositions comprising predominately dissolved pyrophosphate refer to compositions where at least one pyrophosphate ion source is in an amount sufficient to provide at least 1.0% free pyrophosphate ions. Compositions comprising pyrophosphate typically contain from 1% to 15%, preferably from 2% to 10%, and most preferably from 2% to 8% pyrophosphate salt, by weight of the composition. The pyrophosphate salts are described in U.S. Patent 4,515,772, issued May 7, 1985, and 4,885,155, issued December 5, 1989, both to Parran et al. The compositions of the present invention may include a polyphosphate source. A polyphosphate is generally understood to consist of three or more phosphate molecules arranged primarily in a linear configuration, although some cyclic derivatives may be present. The inorganic polyphosphate salts desired include sodium tripolyphosphate, tetrapolyphosphate, and hexametaphosphate, among others. Polyphosphates larger than tetrapolyphosphate usually occur as amorphous glassy materials. Preferred are polyphosphates manufactured by FMC Corporation which are commercially known as Sodaphos (n=6), Hexaphos (n=13), and Glass H (n=21). The polyphosphate source will typically comprise from 0.5% to 20%, preferably from 4% to 15%, more preferably from 6% to 10%, and most preferably from 7% to 9%, by weight of the dentifrice composition. The phosphate sources are described in more detail in Kirk & Othmer, Encyclopedia of Chemical Technology, Fourth Edition, Volume 18, Wiley-Interscience Publishers (1996), pages 685-707. Optional agents to be used in place of or in combination with the polyphosphate or pyrophosphate salt include such materials known to be effective in reducing calcium phosphate mineral deposition related to calculus formation. Agents included are synthetic anionic polymers [including polyacrylates and copolymers of maleic anhydride or acid and methyl vinyl ether (e.g., Gantrez), as described, for example, in U.S. Patent 4,627,977, to Gaffar et al.; as well as, e.g., polyamino propoane sulfonic acid (AMPS)], zinc citrate trihydrate, diphosphonates (e.g., EHDP; AHP), polypeptides (such as polyaspartic and polyglutamic acids), and mixtures thereof. Alkali Metal Bicarbonate Salt The dentifrice compositions of the present invention may also include an alkali metal bicarbonate salt. The alkali metal bicarbonate salt may be present in one or both dentifrice composition or in the single dentifrice composition. Sodium bicarbonate, also known as baking soda, is the preferred alkali metal bicarbonate salt. The present composition may contain from 6% to 50%, preferably from 7% to 30%, more preferably from 8% to 20%, and most preferably from 8% to 18% of an alkali metal bicarbonate salt, by weight of the dentifrice composition. Calcium Peroxide The present invention may include calcium peroxide in any of the dentifrice compositions. The following amounts represent the amount of peroxide raw material, although the peroxide source may contain ingredients other than the peroxide raw material. The present composition may contain from 0.01% to 10%, preferably from 0.1% to 5%, more preferably from 0.2% to 3%, and most preferably from 0.3% to 0.8% of a peroxide source, by weight of the dentifrice composition. Abrasive Polishing Materials An abrasive polishing material may also be included in the dentifrice compositions. The abrasive polishing material contemplated for use in the compositions of the present invention can be any material which does not excessively abrade dentin. Typical abrasive polishing materials include silicas including gels and precipitates; aluminas; phosphates including orthophosphates, polymetaphosphates, and insoluble pyrophosphates; and mixtures thereof. Silica dental abrasives of various types are preferred because of their unique benefits of exceptional dental cleaning and polishing performance without unduly abrading tooth enamel or dentine. The silica abrasive polishing materials herein, as well as other abrasives, generally have an average particle size ranging between 0.1 to 30 microns, and preferably from 5 to 15 microns. The abrasive can be precipitated silica or silica gels such as the silica xerogels described in Pader et al., U.S. Patent 3,538,230, issued Mar. 2, 1970, and DiGiulio, U.S. Patent 3,862,307, issued Jan. 21, 1975. Preferred are the precipitated silica materials such as those marketed by the J. M. Huber Corporation under the trade name, "Zeodent", particularly the silica carrying the designation "Zeodent 119". The types of silica dental abrasives useful in the toothpastes of the present invention are described in more detail in Wason, U.S. Patent 4,340,583, issued July 29, 1982, and in Rice, U.S. Patent 5,589,160, issued December 31, 1996. Silica abrasives are also described in WO 96/34592 and WO 96/34593. The abrasive in the toothpaste compositions described herein is generally present at a level of from 6% to 70% by weight of the composition. Preferably, toothpastes contain from 10% to 50% of abrasive, by weight of the dentifrice composition. Propylene Glycol The dentifrice compositions may also comprise propylene glycol. The propylene glycol is suitable for use on the skin and mucosal surfaces such as in the oral cavity. The first dentifrice composition may contain from 0.5% to 30%, preferably from 1% to 20%, and more preferably from 2% to 15% of propylene glycol, by weight of the dentifrice composition. Acidic Compound The dentifrice compositions of the present invention may incorporate an acidic compound. The acidic compound may be organic or inorganic. The acidic compound may be any material which will be a proton donor that is capable of neutralizing bicarbonate. Acidic compounds suitable for use include carboxylic acids, phosphoric acids, alpha-hydroxy acids, sulfonic acids, and mixture thereof. Specific acids include citric acid, malic acid, alginic acid, succinic acid, lactic acid, tartaric acid, glycolic acid, adipic acid, potassium bitartrate acid, acid sodium citrate, phosphoric acid, boric acid, and acid phosphate and pyrophosphate salts. A blend of acids are preferred. Citric acid and malic acid are preferred. Acid anhydrides and acid salts of the above acids may also be used. Suitable salts include mono or disodium salts of citric acid, mono sodium salts of malic acid, and mixtures thereof. The second dentifrice composition may contain from 0.5% to 20%, preferably from 1% to 15%, and more preferably from 4% to 12% of an acidic compound, by weight of the dentifrice composition. Buffering Agent The dentifrice compositions may contain a buffering agent. Buffering agents, as used herein, refer to agents that can be used to adjust the pH of the compositions. The buffering agents suitable include alkali metal hydroxides, carbonates, sesquicarbonates, borates, silicates, phosphates, imidazole, and mixtures thereof. Specific buffering agents include monosodium phosphate, trisodium phosphate, sodium hydroxide, potassium hydroxide, alkali metal carbonate salts, sodium carbonate, imidazole, pyrophosphate salts, sodium acid pyrophosphate, sodium citrate, and sodium malate. Buffering agents are used at a level of from 0.1% to 30%, preferably from 1% to 10%, and more preferably from 1.5% to 3%, by weight of the dentifrice composition. Polyoxyethylene The compositions of the present invention may include a polyoxyethylene. The polyoxyethylene will increase the amount of foam and the thickness of the foam. Polyoxyethylene is also commonly known as polyethylene glycol ("PEG") or polyethylene oxide. The polyoxyethylenes suitable for this invention will have a molecular weight of from 200,000 to 7,000,000. Preferably, the molecular weights will be from 600,000 to 2,000,000, and more preferably from 800,000 to 1,000,000. "Polyox" is the tradename for the high molecular weight polyoxyethylene produced by Union Carbide. The polyoxyethylene is present in an amount of from 0.1% to 8%, preferably from 0.2% to 5%, and more preferably from 0.3% to 2%, by weight of the dentifrice composition. The present invention compositions in the form of toothpastes, typically contain some thickening material or binders to provide a desirable consistency. Preferred thickening agents are carboxyvinyl polymers, carrageenan, hydroxyethyl cellulose, and water soluble salts of cellulose ethers such as sodium carboxymethylcellulose and sodium hydroxyethyl cellulose. Natural gums such as gum karaya, xanthan gum, gum arabic, and gum tragacanth can also be used. Colloidal magnesium aluminum silicate or finely divided silica can be used as part of the thickening agent to further improve texture. Thickening agents can be used in an of amount from 0.1% to 15%, by weight of the dentifrice composition. Another optional component of the compositions desired herein is a humectant. The humectant serves to keep toothpaste compositions from hardening upon exposure to air and certain humectants can also impart desirable sweetness of flavor to toothpaste compositions. Suitable humectants for use in the invention include glycerin, sorbitol, polyethylene glycol, and other edible polyhydric alcohols. The polyethylene glycol may have a molecular weight of from 200 to 7000. The humectant generally comprises from 0% to 70%, and preferably from 15% to 55%, by weight of the dentifrice composition. Water employed in the preparation of commercially suitable dentifrice compositions should preferably be of low ion content and free of organic impurities. Water will generally comprise from 5% to 70%, and preferably from 10% to 50%, by weight of the composition herein. Alternatively, the dentifrice compositions may comprise a lower level of water, generally from 5% to 20%, preferably from 7% to 14%, and more preferably from 7% to 12%, by weight of the dentifrice composition. The lower level of water is preferred in compositions comprising polyphosphates. The amounts of water include the free water which is added plus that which is introduced with other materials, such as with sorbitol, silica, surfactant solutions, and/or color solutions. The present compositions may also comprise additional nonionic surfactants, also commonly referred to as sudsing agents. Nonionic surfactants which can be used in the compositions of the present invention 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. Examples of suitable nonionic surfactants include poloxamers (sold under trade name Pluronic), polyoxyethylene, polyoxyethylene sorbitan esters (sold under trade name Tweens), and mixtures of such materials. Many suitable nonionic surfactants are disclosed by Gieske et al., U.S. Patent 4,051,234, issued September 27, 1977. The present composition may comprise one or more surfactants each at a level of from 0.25% to 12%, preferably from 0.5% to 8%, and most preferably from 1% to 6%, by weight of the composition. Titanium dioxide may also be added to the present composition. Titanium dioxide is a white powder which adds opacity to the compositions. Titanium dioxide generally comprises from 0.25% to 5%, by weight of the composition. Coloring agents may also be added to the present composition. The coloring agent may be in the form of an aqueous solution, preferably 1% coloring agent in a solution of water. Color solutions generally comprise from 0.01% to 5%, by weight of the composition. A flavor system can also be added to the compositions. 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. A flavor system is generally used in the compositions at levels of from 0.001% to 5%, by weight of the composition. Coolants may also be part of the flavor system or added separately to the composition. Preferred coolants in the present compositions are the paramenthan carboxyamide agents such as N-ethyl-p-menthan-3-carboxamide (known commercially as "WS-3"), menthol, 3-1-menthoxypropane-1,2-diol ("TK-10"), menthone glycerol acetal ("MGA"), menthyl lactate, and mixtures thereof. A coolant is generally used in the compositions at levels of from 0.001% to 5%, by weight of the composition. The present compositions may also include xylitol. Xylitol is a sugar alcohol that is used as a sweetener and humectant. Xylitol may provide a therapeutic effect, such as an antibacterial or anticaries effect. The present compositions typically comprise xylitol at a level from 0.01% to 25%, preferably from 3% to 15%, more preferably from 5% to 12%, and most preferably from 9% to 11%, by weight of the total composition. Alternatively, if xylitol is used as a sweetener, it may be present at a lower level, such as from 0.005% to 5%, by weight of the dentifrice composition. Sweetening agents can be added to the compositions. These include saccharin, dextrose, sucrose, lactose, maltose, levulose, aspartame, sodium cyclamate, D-tryptophan, dihydrochalcones, acesulfame, and mixtures thereof. Various coloring agents may also be incorporated in the present invention. Sweetening agents and coloring agents are generally used in toothpastes at levels of from 0.005% to 5%, by weight of the composition. The present compositions may also include other agents, such as antimicrobial agents. Included among such agents are water insoluble non-cationic antimicrobial agents and water soluble antimicrobials, such as quaternary ammonium salts and bis-biquanide salts, among others. Triclosan monophosphate is an additional water soluble antimicrobial agent. Other compounds are bis[4-(R-amino)-1-pyridinium] alkanes as disclosed in U.S. Patent 4,206,215, issued June 3, 1980, to Bailey. Stannous salts such as stannous pyrophosphate and stannous gluconate and other antimicrobials such as copper bisglycinate, copper glycinate, zinc citrate, and zinc lactate may also be included. Also useful are enzymes, including endoglycosidase, papain, dextranase, mutanase, and mixtures thereof. Such agents are disclosed in U.S. Patent 2,946,725, Jul. 26, 1960, to Norris et al. and in U.S. Patent 4,051,234, September. 27, 1977 to Gieske et al. Specific antimicrobial agents include chlorhexidine, triclosan, tnclosan monophosphate, and flavor oils such as thymol. Triclosan and other agents of this type are disclosed in Parran, Jr. et al., U.S. Patent 5,015,466, issued May 14, 1991, and U.S. Patent 4,894,220, Jan. 16, 1990 to Nabi et al. These agents may be present at levels of from 0.01% to 1.5%, by weight of the dentifrice composition. The dentifrice formulation may contain a first and second dentifrice composition or a single dentifrice composition. If there are two dentifrice compositions, the first and second dentifrice compositions will be physically separated in a dentifrice dispenser. The dentifrice compositions may be a paste, gel, or any configuration or combination thereof. It is preferred that the first dentifrice composition be a gel and the second dentifrice composition be a paste. The dispenser may be a tube, pump, or any other container suitable for dispensing toothpaste. Dual compartment packages suitable for this purpose are described in U.S. Patent 4,528,180, issued July 9, 1985; U.S. Patent 4,687,663, issued August 18, 1987; and 4,849,213, issued July 18, 1989, all to Shaeffer. The dispenser will deliver approximately equal amounts of each dentifrice composition through an opening. The compositions may intermix once dispensed. Alternatively, the dentifrice formulation may be delivered from a kit containing two separate dispensers which are used to deliver two dentifrice compositions that are both used simultaneously. EXAMPLE I First Dentifrice Composition Second Dentifrice Composition Ingredient Wt. % Ingredient Wt. % Carboxymethylcellulose 0.90 Color 0.30 Water 15.00 Water 29.06 Flavor 1.00 Flavor 1.00 Glycerin 24.76 Triclosan 0.60 Calcium Peroxide 1.00 Carbopol 2.50 Sodium Fluoride 0.24 Sodium Hydroxide 1.00 Sodium Alkyl Sulfate 4.00 Sodium Saccharin 0.40 Silica 22.00 Sodium Alkyl Sulfate 2.00 Sodium Carbonate 2.00 Betaine 2.90 Sodium Saccharin 0.40 Sorbitol 60.00 Sodium bicarbonate 14.50 Sodium Fluorine 0.24 Titanium Dioxide 1.00 Xantham Gum 0.20 Polyethylene Glycol 3.00 Tetrasodium Pyrophosphate 10.00 The first dentifrice composition is prepared as follows. Place the water in a mixing vessel and add sodium fluoride and saccharin. Disperse the thickening agents, carboxymethylcellulose and xanthan gum, in the glycerin, before adding to the mixture. Add the polyethylene glycol. Next add the flavor system, titanium dioxide, and sodium alkyl sulfate. Add the sodium carbonate. Add the silica and then the sodium bicarbonate. Lastly, slowly add the tetrasodium pyrophosphate and finally the calcium peroxide. Continue mixing until homogeneous. Mill and/or deaerate the final product if desired for aesthetic preference. For the second dentifrice composition, add the water, saccharin, color, and fluoride to the mixing vessel. Heat to at least 40°C. Premix the Carbopol in the sorbitol. Add this premix to the mixing vessel and mix well. Premix the flavor, triclosan, and sodium alkyl sulfate until uniform in color and then add the betaine. Add this premix to the mixing vessel and mix well. Add the sodium hydroxide to the mixture and continue to mix until homogeneous. EXAMPLE II First Dentifrice Composition Second Dentifrice Composition Ingredient Wt. % Ingredient Wt. % Carboxymethylcellulose 0.80 Color 0.30 Water 10.00 Water 48.00 Flavor 1.00 Flavor 0.80 Glycerin 8.00 Glycerin 39.76 Sodium Fluoride 0.24 Carbopol 2.60 Sorbitol 25.06 Sodium Hydroxide 1.00 Sodium Alkyl Sulfate 4.00 Sodium Saccharin 0.40 Silica 15.00 Sodium Alkyl Sulfate 2.00 Sodium Carbonate 2.00 Betaine 2.90 Sodium Saccharin 0.40 Polyoxyethylene 2.00 Sodium Bicarbonate 30.00 Sodium Fluoride 0.24 Titanium Dioxide 0.50 Polyethylene Glycol 3.00 The first dentifrice composition is prepared as follows. Add the water, sodium fluoride, and saccharin to a mixing vessel. Disperse the thickening agents, carboxymethylcellulose, in the glycerin and sorbitol, before adding to the mixture. Add the polyethylene glycol, flavor system, and titanium dioxide. Add the sodium alkyl sulfate. Next add the sodium carbonate, silica, and then the sodium bicarbonate. Continue mixing until homogeneous. Mill and/or deaerate the final product if desired for aesthetic preference. For the second dentifrice composition, add the water, saccharin, color, and fluoride to the mixing vessel. Heat to at least 40°C. Premix the Carbopol and polyoxyethylene in the glycerin. Add this premix to the mixing vessel and mix well. Premix the flavor and sodium alkyl sulfate until uniform in color and then add the betaine. Add this premix to the mixing vessel and mix well. Add the sodium hydroxide to the mixture and continue to mix until homogeneous. EXAMPLE III First Dentifrice Composition Second Dentifrice Composition Ingredient Wt. % Ingredient Wt. % Carboxymethylcellulose 0.45 Color 0.30 Water 5.00 Water 48.00 Flavor 0.90 Flavor 0.80 Glycerin 34.00 Glycerin 38.44 Xantham Gum 0.25 Carbopol 2.60 Poloxamer 3.00 Sodium Hydroxide 1.00 Sodium Alkyl Sulfate 4.00 Sodium Saccharin 0.40 Silica 19.00 Sodium Alkyl Sulfate 2.00 Sodium Carbonate 2.00 Betaine 2.90 Sodium Saccharin 0.40 Polyoxyethylene 3.00 Sodium Bicarbonate 9.00 Sodium Fluoride 0.56 Titanium Dioxide 1.00 Polyethylene Glycol 3.00 Glass H Polyphosphate 10.00 Propylene Glycol 8.00 The first dentifrice composition is prepared as follows. Add the saccharin and water to a mixing vessel. Disperse the thickening agents, carboxymethyl cellulose and xanthan gum, in the glycerin. Add this mixture of dispersed thickening agents in glycerin to the mixing vessel and mix well. Add the flavor, Poloxamer, polyethylene glycol, propylene glycol, titanium dioxide, and sodium alkyl sulfate to the mixture and mix until homogeneous. Next add the sodium carbonate and the silica. After mixing, add the sodium bicarbonate. Finally add the polyphosphate. Continue stirring the mixture until homogeneous. For the second dentifrice composition, add the water, saccharin, color, and fluoride to the mixing vessel. Heat to at least 40°C. Premix the Carbopol and polyoxyethylene in the glycerin. Add this premix to the mixing vessel and mix well. Premix the flavor and sodium alkyl sulfate until uniform in color and then add the betaine. Add this premix to the mixing vessel and mix well. Add the sodium hydroxide to the mixture and continue to mix until homogeneous. EXAMPLE IV Ingredient Weight % Glycerin 40.00 Water 49.76 Betaine 2.90 Sodium Fluoride 0.24 Sodium Saccharin 0.40 Sodium Alkyl Sulfate 2.00 Flavor System 0.80 Color 0.30 Carbopol 2.60 Sodium Hydroxide 1.00 The dentifrice composition is prepared as follows. Add the water, saccharin, color, and fluoride to the mixing vessel. Heat to at least 40°C. Premix the Carbopol in the glycerin. Add this premix to the mixing vessel and mix well. Premix the flavor and sodium alkyl sulfate until uniform in color and then add the betaine. Add this premix to the mixing vessel and mix well. Add the sodium hydroxide to the mixture and continue to mix until homogeneous. EXAMPLE V Ingredient Weight % Glycerin 32.26 Water 38.00 Sodium Fluoride 0.24 Sodium Saccharin 0.40 Silica 20.00 Sodium Alkyl Sulfate 4 00 Flavor System 0.80 Color 0.30 JR-30M PolyQuat 4.00 Example V is prepared as follows. Add the water, saccharin, color, and fluoride to the mixing vessel. Heat to at least 40°C. Premix the PolyQuat in the glycerin. Add this premix to the mixing vessel and mix well. Premix the flavor and sodium alkyl sulfate until uniform in color and add this premix to the mixing vessel. Add the silica to the mixture and continue to mix until homogeneous. Mill and/or deaerate the final product if desired for aesthetic preference

Claims: A dentifrice composition comprising: a) a coacervate gel comprising either, i) from 0.1% to 10% by weight of the composition of an anionic polymer; and ii) from 0.1% to 10% by weight of the composition of a surfactant selected from cationic surfactants, amphoteric surfactants, and mixtures thereof; or iii) from 0.1% to 10% by weight of the composition of a cationic polymer; and iv) from 0.1% to 10% by weight of the composition of a surfactant selected from anionic surfactants, amphoteric surfactants, and mixtures thereof; and b) from 80% to 99% of one or more aqueous carriers. The dentifrice composition according to Claim 1 wherein the coacervate gel comprises an anionic polymer. The dentifrice composition according to Claim 2 wherein the anionic polymer is a carboxyvinyl polymer. The dentifrice composition according to Claim 3 wherein the surfactant is cocoamidopropyl betaine. The dentifrice composition according to Claim 4 which further comprises sodium alkyl sulfate. A dentifrice formulation comprising first and second dentifrice compositions contained in physically separated compartments of a dispenser, wherein the first dentifrice composition is formulated according to any of Claims 1 to 5. The dentifrice formulation according to Claim 6 wherein the first dentifrice composition is in the form of a gel and the second dentifrice composition is in the form of a paste. A process for making a dentifrice composition according to Claim 1 comprising a coacervate gel, the process comprising the steps of: a) forming a slurry, having a pH of from 1.5 to 4.5, of an amonic polymer, a humectant and other dentifrice ingredients; b) adding a surfactant selected from cationic surfactants, amphoteric surfactants, and mixtures thereof to the slurry; and c) optionally adjusting the pH of the composition to a pH of from 4.5 to 6. A process for making a dentifrice composition according to Claim 1 comprising a coacervate gel, the process comprising the steps of: a) forming a slurry, having a pH of from 7.5 to 9, of a cationic polymer, a humectant and other dentifrice ingredients; b) adding a surfactant selected from anionic surfactants, amphoteric surfactants, and mixtures thereof to the slurry and c) optionally adjusting the pH of the composition to a pH of from 4 to 8.5. The process according to Claim 8 or Claim 9 wherein the dentifrice composition further comprises a flavor system, the flavor system being emulsified with the surfactant before the coacervate gel is formed.

Inventors: GLANDORF WILLIAM MICHAEL, GLANDORF, WILLIAM MICHAEL
Applicants: PROCTER & GAMBLE, THE PROCTER & GAMBLE COMPANY
Application year: 1998
Main classification: A61K7