Oral compositions

Abstract: Oral compositions containing as an anticalculus agent an acrylic acid polymer or copolymer having a mass average mo­ lecular weight of from about 3500 to about 7500 are described herein.

Description: The present invention relates to oral compositions such as liquid dentifrices, toothpastes and mouthwashes, which provide an anticalculus benefit. Dental calculus, or tartar as it is sometimes called, is a deposit which forms on the surfaces of the teeth at the gingival margin. Supragingival calculus appears principally in the areas near the orifices of the salivary ducts; e.g., on the lingual surfaces of the lower anterior teeth and on the buccal surfaces of the upper first and second molars, and on the distal surfaces of the posterior molars. Mature calculus consists of an inorganic portion which is largely calcium phosphate arranged in a hydroxyapatite crystal lattice structure similar to bone, enamel and dentine. An organic portion is also present and consists of desquamated epithelial cells, leukocytes, salivary sediment, food debris and various types of microorganisms. As the mature calculus develops, it becomes visibly white or yellowish in color unless stained or discolored by some extraneous agent. In addition to being unsightly and undesirable from an aesthetic standpoint, the mature calculus deposits are regarded by many as a constant source of mechanical irritation of the gingiva. A wide variety of chemical and biological agents have been suggested in the art to retard calculus formation or to remove calculus after it is formed. Mechanical removal of this material periodically by the dentist is, of course, routine dental office procedure. The chemical approach to calculus inhibition generally involves chelation of calcium ion and/or crystal growth inhibition which prevents the calculus from forming and/or breaks down mature calculus by removing calcium. The prior art discloses a number of chelating agents for this purpose. GB-A-490,384 , February 15, 1937 discloses oral compositions containing ethylenediaminetetraacetic acid, nitrilotriacetic acid and related compounds as anticalculus agents. US-A-3,678,154 , July 18, 1972 to Widder et al. discloses oral compositions containing certain polyphosphonates and fluoride. US-A-3,737,533, June 5, 1973 to Francis discloses oral compositions containing certain carbonyl diphosphonates. In addition to the above references, the prior art discloses dentifrices and mouthwashes containing soluble pyrophosphate salts which have been included for a variety of purposes. Included among such references are US-A-2,941,926, June 21, 1960 to Salzmann et al. which discloses dental powders containing chlorophyll and pyrophosphate salts. US-A-3,137,632 , June 16, 1964 to Schiraldi discloses toothpastes containing pyrophosphate salts. US-A-3,927,201 and US-A-3,927,202 , December 16, 1975 to Baines et al. and Harvey et al., respectively, disclose toothpastes which utilize soluble pyrophosphates as abrasives. US-A-4,244,931 , January 13, 1981 and US-A-4,247,526 , January 27, 1981 to Jarvis et al. disclose pyrophosphate salts in dicalcium phosphate systems. Jap. Patent Application Disclosure No. 4945-1974 discloses soluble pyrophosphates in a variety of dentifrice systems. US-A-4,333,551 , April 6, 1982 to Parran discloses tetraalkali metal salts in mouthwash compositions. In addition to the use of the above mentioned materials the use of certain acrylic acid polymers and other agents have also been disclosed for use as anticalculus agents. Included among such agents are polyelectrolytes such as copolymers of maleic anhydride and ethylene disclosed in US-A-3,429,963 , February 25, 1969 to Shedlovsky. Shedlovsky also discloses polyacrylic acid having an average molecular weight of 1500 and greater. Other references disclosing polyacrylic acids in oral compositions are ZA-A-720898 , September 12, 1972 which discloses such acids having a molecular weight of from 1000 to 2,000,000; and US-A-4,304,766 , December 8, 1971 to Chang discloses polyacrylic acid having a molecular weight in the range of 2,000 to 4,000,000 for use as a membrane to prevent the elution from teeth of previously applied agents. Finally US-A-3,956,480 , May 11, 1976 discloses complexes of anionic polymers (e.g.. acrylic acid) and a cationic therapeutic agent (e.g., chlorhexidine) as anticalculus agents. In spite of the many disclosures in the anticalculus area, the need for improved anticalculus products still exist. The prior art, while suggesting the use of polyacrylic acid polymers or copolymers in oral compositions, does not suggest the need for using such uncomplexed polymers within a particular molecular weight range to achieve maximum anticalculus efficacy. It is an object of the present invention to provide compositions which deliver an effective anticalculus benefit. It is a further object of the present invention to provide an effective anticalculus product utilizing polyacrylic acid polymers or copolymers having a mass average molecular weight of from 3500 to 7500. It is a further object of the present invention to provide an anticalculus product which does not inhibit remineralization of the teeth. It is still a further object of the present invention to provide compositions which are cosmetically acceptable. These and other objects will become more clear from the detailed description which follows. All percentages and ratios used herein are by weight unless otherwise specified. The present invention relates to an oral composition comprising: a) from 2.5% to 20% by weight of a polyacrylic acid polymer or copolymer as defined herein below having a mass average molecular weight of from 3500 to 7500; and b) a pharmaceutically acceptable carrier. DETAILED DESCRIPTION OF THE INVENTION The compositions of the present invention comprise particular polyacrylic acid polymers or copolymers and a pharmaceutically acceptable carrier. By the term "comprising", as used herein, is meant that various additional components can be conjointly employed in the compositions of this invention as long as the polyacrylic acid polymer or copolymer performs its intended functions. By the term "carrier", as used herein, is meant a suitable vehicle which is pharmaceutically acceptable and can be used to apply the present compositions in the oral cavity. Polyacrylic Acid The anticalculus agent useful in the compositions of the present invention are polyacrylic acid polymers or copolymers having a mass average molecular weight of from 3500 to 7500. Polyacrylic acid polymers are staple items of commerce and are made by polymerizing acrylic acid, to form the repeating chain the repetition being sufficient to provide the molecular weight desired. M may be an alkali metal or ammonium ion or hydrogen. Polymers of the type useful in the present invention are available from Rohm and Haas Company. Copolymers of acrylic acid and other monomers may also be used in the present invention, namely methacrylic acid, 2-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 3-hydroxy propyl acrylate and acrylamide, and mixtures thereof. It is preferred that with methacrylic acid, the number of acrylic acid units in the polymer be a least 50% of the total units present. With other monomers it is preferred that the percentage be at least 80%. While the molecular weight may be in the range of 3500 to 7500, preferably the molecular weight is from 4000 to 5500, most preferably from 4300 to 5200. A particularly preferred material is a polyacrylic acid polymer having a molecular weight of about 4500 which can be provided by Rohm and Haas carrying the identification LMW-45. The amount of the polymer used in the present compositions is from 2.5% to 20%, preferably from 3% to 10%, most preferably from 4% to 8%. Mixtures of polyacrylic acid polymers or copolymers are also useful in the present invention. Pharmaceutically Acceptable Carrier The carrier for the polyacrylic acid polymer or copolymer can be any vehicle suitable for use in the oral cavity. Such carriers include the usual components of mouthwashes, toothpastes, tooth powders, prophylaxis pastes, lozenges, gums and the like and are more fully described hereinafter. Dentifrices and mouthwashes are the preferred systems. The abrasive polishing material contemplated for use in the present invention can be any material which does not excessively abrade dentin. These include, for example, silicas including gels and precipitates, calcium carbonate, dicalcium orthophosphate dihydrate, calcium pyrophosphate, tricalcium phosphate, calcium polymetaphosphate, insoluble sodium polymetaphosphate, hydrated alumina, and resinous abrasive materials such as particulate condensation products of urea and formaldehyde, and others such as disclosed by Cooley et al. in US-A-3,070,510, December 25, 1962. Mixtures of abrasives may also be used. Silica dental abrasives, of various types, can provide the unique benefits of exceptional dental cleaning and polishing performance without unduly abrading tooth enamel or dentin. Silica abrasive materials are also exceptionally compatible with sources of soluble fluoride. For these reasons they are preferred for use herein. The silica abrasive polishing materials useful herein, as well as the other abrasives, generally have an average particle size ranging between about 0. 1 and 30µm, preferably 5 and 15µm. The silica abrasive can be precipitated silica or silica gels such as the silica xerogels described in Pader et al., US-A-3,538,230, issued March 2, 1970 and DiGiulio, US-A-3,862,307, June 21, 1975. Preferred are the silica xerogels marketed under the tradename "Syloid" by the W. R. Grace & Company, Davison Chemical Division. Preferred precipitated silica materials include those marketed by the J. M. Huber Corporation under the tradename, "Zeodent", particularly the silica carrying the designation "Zeodent 119". These silica abrasives are described in US-A-4,340,583, July 29, 1982, The abrasive in the compositions described herein is present at a level of from 6% to 70%, preferably from 15% to 25% when the dentifrice is a toothpaste. Higher levels, as high as 90%, may be used if the composition is a toothpowder. Flavoring agents can also be added to dentifrice compositions. Suitable flavoring agents include oil of wintergreen, oil of peppermint, oil of spearmint, oil of sassafras, and oil of clove. Sweetening agents which can be used include aspartame, acesulfame, saccharin, dextrose, levulose and sodium cyclamate. Flavoring and sweetening agents are generally used in dentifrices at levels of from 0.005% to 2% by weight. Dentifrice compositions can also contain emulsifying agents. Suitable emulsifying agents are those which are reasonably stable and foam throughout a wide pH range, including non-soap anionic, nonionic, cationic, zwitterionic and amphoteric organic synthetic detergents. Many of these suitable surfactants are disclosed by Gieske et al. in US-A-4,051,234, September 27, 1977. It is common to have a water-soluble fluoride compound present in dentifrices in an amount sufficient to give a fluoride concentration of from 0.0025% to 5.0% by weight, preferably from 0.005% to 2.0% by weight, to provide additional anticaries effectiveness. Preferred fluorides are sodium fluoride, stannous fluoride, indium fluoride, and sodium monofluorophosphate. Norris et al., US-A-2,946,735, issued July 26, 1960 and Widder et al., US-A-3,678,154, issued July 18, 1972 disclose such salts as well as others. Water is also present in the toothpastes of this invention. Water employed in the preparation of commercially suitable toothpastes should preferably be deionized and free of organic impurities. Water generally comprises from 10% to 50%, preferably from 20% to 40%, by weight of the toothpaste compositions herein. These amounts of water include the free water which is added plus that which is introduced with other materials such as with sorbitol. In preparing toothpastes, it is necessary to add some thickening material to provide a desirable consistency. Preferred thickening agents are carboxyvinyl polymers, carrageenan, hydroxyethyl cellulose and water soluble salts of cellulose ethers such as sodium carboxymethyl cellulose and sodium carboxymethyl hydroxyethyl cellulose. Natural gums such as gum karaya, 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 in an amount from 0.5% to 5.0% by weight of the total composition can be used. It is also desirable to include some humectant material in a toothpaste to keep it from hardening. Suitable humectants include glycerin, sorbitol, and other edible polyhydric alcohols at a level of from 15% to 70%. Another preferred embodiment of the present invention is a mouthwash composition. Conventional mouthwash composition components can comprise the carrier for the antimicrobial of the present invention. Mouthwashes generally comprise from 20:1 to 2:1 of a water-ethyl alcohol solution and preferably other ingredients such as flavor, sweeteners, humectants and sudsing agents such as those mentioned above for dentifrices. The humectants, such as glycerin and sorbitol give a moist feel to the mouth. Generally, on a weight basis the mouthwashes of the invention comprise 5% to 60% (preferably 10% to 25%) ethyl alcohol, 0% to 20% (preferably 5% to 20%) of a humectant, 0% to 2% (preferably 0.01% to 0.15%) emulsifying agent, 0% to 0.5% (preferably 0.005% to 0.06%) sweetening agent such as saccharin, 0% to 0.3% (preferably 0.03% to 0.3%) flavoring agent, and the balance water. The amount of antimicrobial agent in mouthwashes is typically from .01 to .5% by weight. Suitable lozenge and chewing gum components are disclosed in US-A-4,083,955, April 11, 1978 to Grabenstetter et al. The pH of the present compositions and or its pH in the mouth can be any pH which is safe for the mouth's hard and soft tissues. Such pH's are generally from 3 to 10, preferably from 4 to 8. METHOD OF MANUFACTURE The carrier compositions of the present invention can be made using methods which are common in the oral products area. For example toothpaste compositions may be prepared by mixing part of the humectant and water together and heating to 66-71°C. The fluoride source, if present, is then added along with the sweetener, the polyacrylic acid polymer or copolymer, the opacifier and the flavor. To this mixture is added the abrasive which is mixed in well. The thickener is then slurried with the remainder of the humectant and milled prior to being added to the other components. COMPOSITION USE The following examples further describe and demonstrate preferred embodiments within the scope of the present invention. EXAMPLE 1 The following composition is representative of the present invention. Component Weight % Sorbitol (70% aqueous solution) 35.000 Water 14.771 PEG-6 1.000 Silica Dental Abrasive . 20.000 Sodium Fluoride 0.243 Titanium dioxide 0.500 Sodium saccharin 0.286 Sodium alkyl sulfate (27.9% aqueous solution) 4.000 Flavor 1.040 Carboxyvinyl Polymer 0.300 Carrageenan 0.800 Polyacrylic acid (34% aqueous solution) 22.060 100.000 EXAMPLE II This composition is another example of the present invention. Component Weight % Sorbitol as in Example I 35.000 Water 15.073 Sodium Fluoride 0.243 PEG-6 1.000 Carrageenan 0.800 Sodium saccharin 0.280 Titanium dioxide 0.500 Flavor 1.044 Silica Dental Abrasive as in Example I 20.000 Sodium alkyl sulfate as in Example I 4.000 Polyacrylic acid (34%) as in Example I 22.060 100.000 The compositions of Example I and II are effective anticalculus products as well as cosmetically acceptable. In the above compositions the abrasive may be replaced by other abrasives such as calcium carbonate. calcium pyrophosphate, tricalcium phosphate, dicalcium othophosphate dihydrate and hydrated alumina with similar results obtained. Similarly other thickeners such as gum arabic and carboxymethyl cellulose may be used as well as other fluoride sources such as stannous fluoride, potassium fluoride, indium fluoride, zinc fluoride and sodium monofluorophosphate. Silicas are the preferred abrasives when fluoride sources are used in the compositions. Other acrylic acid polymers or copolymers having molecular weights in the range of 3500 to 7500 may also be used in place of the 4500 molecular weight material. EXAMPLE III The following mouthwash composition is another composition of the present invention. Component Weight % SDA 40 Alcohol 8.00 Flavor 0.08 Emulsifier 0.08 Sodium Fluoride 0.05 Glycerin 10.00 Sweetener 0.02 Benzoic acid 0.05 Sodium hydroxide 0.20 Dye 0.04 Water 66.78 Polyacrylic acid (34%) as in Example I 14.70 100.00 EXAMPLE IV The following is a lozenge composition of the present invention. Component Weight % Sorbitol 17.5 Mannitol 17.5 Starch 13.6 Sweetener 1.2 Flavor 11.7 Color 0.1 Polyacrylic acid (34%) as in Example I 12.8 Corn syrup balance The compositions of Examples III and IV are also effective anticalculus products and are cosmetically acceptable.

Claims: An oral composition effective in reducing calculus comprising: (a) from 2.5% to 20% by weight of an anticalculus agent selected from polyacrylic acid polymers, copolymers of polyacrylic acid and another monomer and mixtures thereof wherein the monomer is selected from methacrylic acid, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, acrylamide and mixtures thereof; and (b) a pharmaceutically acceptable carrier characterized in that said anticalculus agent has a mass average molecular weight of from 3500 to 7500. An oral composition according to Claim 1 wherein the molecular weight of the anticalculus agent is from 4000 to 5500. An oral composition according to Claim 1 or 2 in the form of a toothpaste. An oral composition according to Claim 3 which contains from 3% to 10% by weight of the anticalculus agent. An oral composition according to Claim 4 wherein the anticalculus agent is a polyacrylic acid polymer having a molecular weight of from 4300 to 5200. An oral composition according to any of Claims 3 to 5 which contains a silica dental abrasive. An oral composition according to any of Claims 3 to 6 which in addition contains a soluble fluoride source. An oral composition according to Claim 1 or 2 in the form of a mouthwash. An oral composition according to Claim 8 wherein the anticalculus agent is a polyacrylic acid polymer. An oral composition according to Claim 1 or 2 which is in the form of a lozenge or a chewing gum.

Inventors: BENEDICT JAMES JOHN, SUNBERG RICHARD JOSEPH, BENEDICT, JAMES JOHN, SUNBERG, RICHARD JOSEPH
Applicants: PROCTER & GAMBLE, THE PROCTER & GAMBLE COMPANY
Application year: 1985
Main classification: A61K7
IPC codes: A61Q11, A61K8