WO1998044900A1

WO1998044900A1 - Dentifrice compositions

Info

Publication number: WO1998044900A1
Application number: PCT/IB1998/000485
Authority: WO
Inventors: Robert Vincent Faller
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1997-04-04
Filing date: 1998-04-02
Publication date: 1998-10-15
Anticipated expiration: 1999-10-04
Also published as: PE70399A1

Abstract

Disclosed are oral compositions employing specific levels of fluoride ions and sodium bicarbonate.

Description

DENTIFRICE COMPOSITIONS

BACKGROUND OF THE INVENTION

This invention relates to novel oral compositions which are exceptionally stable in terms of their ability to provide therapeutic amounts of soluble fluoride for treatment of dental tissue. The improved fluoride stability is important since fluoride ions are believed to interact with dental enamel to reduce the enamel's acid solubility, as well as enhance remineralization and reversal of carious enamel, and to inhibit demineralization of enamel.

It has been postulated that the effectiveness of fluoride toothpastes in providing enamel antisolubility benefits is dependent upon the amount of fluoride ion which is available for uptake by the enamel being treated. It is, of course, therefore desirable to formulate toothpaste products which provide maximum fluoride ion availability in brushing solutions formed therefrom.

Formulation of toothpastes which provide desirable levels of soluble fluoride is not accomplished without certain difficulties. All fluoride oral compositions tend, upon storage, to lose their capability of providing their theoretical maximum amount of soluble fluoride. Fluoride ion sources tend to interact with composition impurities and with such components as abrasives, buffers, etc. Such interaction diminishes the ability of the fluoride source to provide "soluble fluoride" upon use. Sodium bicarbonate has been found by the present inventor to enhance the effectiveness of certain levels of fluoride thereby reducing possible concerns over high levels of fluoride.

Oral compositions containing fluoride salts and sodium bicarbonate (i.e., baking soda) are known, having been described, for example, in U.S. Patent 5,180,576, to Winston et al., issued January 19, 1993, the disclosure of which is incorporated herein by reference in its entirety. This patent discloses compositions containing baking soda and a soluble fluoride source. The patent in Column 6 at lines 4-12 discloses fluoride ion levels in the range of 25 - 5000 ppm, preferably 850 to 1500 ppm. The present inventor has surprisingly found that if the fluoride ion level in the product is in the range of 200 - 800 ppm, preferably from about 500 to about 750 ppm, the anticaries effect of the product can be increased by adding from about 10 to about 30% of sodium bicarbonate.

It is therefore an object of the present invention of provide a product having excellent anticaries performance while using a relatively low level of fluoride ions.

It is another object of the present invention to provide products having good aesthetic properties.

It is still another object of the present invention to provide products having the ability to reduce calculus.

SUMMARY OF THE INNENTION

The present invention relates to oral compositions comprising sodium bicarbonate and a soluble fluoride ion source capable of providing from about 200 to about 800 ppm of fluoride ions to the composition.

Also a part of this invention is to provide the effect of higher fluoride ion levels even though lower levels are actually present in the composition. A method of enhancing the mineralization of teeth of a human in such need is also included.

All percentges are by weight of the total compositions and all measurements are made at 25°C unless otherwise specified.

DETAILED DESCRIPTION OF THE INVENTION The essential and optional components of the present invention are set forth in detail. Sodium Bicarbonate

Sodium bicarbonate, also known as baking soda, is a household product with a variety of uses including use in dentifrices and mouthrinses. It is a white powder that is soluble in water and unless stabilized, tends to release carbon dioxide in an aqueous system. The present compositions contain from about 10% to about 30%, preferably from about 15% to about 20%, sodium bicarbonate by weight of the composition. Soluble Fluoride Ion Source:

A soluble fluoride ion source is also incorporated into the present compositions. The soluble fluoride ion source is used in amounts sufficient to provide from about 200 to about 800 ppm of the fluoride ion. Preferred fluorides are sodium fluoride, stannous fluoride, indium fluoride, and sodium monofluorophosphate. Norris et al., U.S. Patent 2,946,735, issued July 26, 1960 and Widder et al., U.S. Patent 3,678,154, issued July 18, 1972 disclose such salts as well as others. Both patents are incorporated herein by reference in their entirety. Carrier Materials

A preferred composition of the present invention is a toothpaste. Mouthwashes are also a preferred carrier.

In preparing the present toothpaste compositions, it is desirable to add one or more dentifrice carrier materials to the compositions. The term "dentifrice carrier materials", as used herein, means any material safe and effective for use in the toothpaste compositions prepared according to the present invention. Such materials are well known in the art and are readily chosen by one skilled in the art based on the physical and aesthetic properties desired for the dentifrice composition being prepared. Dentifrice carrier materials typically comprise from about 50% to about 94%, preferably from about 60% to about 80%, by weight of the present invention compositions.

The present invention toothpaste compositions typically contain 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, 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 amount from about 0.2% to about 5% by weight of the total composition.

It is also desirable to include some humectant material in a toothpaste to keep the composition from hardening upon exposure to air. Certain humectants can also impart a desirable sweetness or flavor to toothpaste compositions and in certain cases provide an effect on bacteria in the mouth. Suitable hu ectants include glycerin, sorbitol, xylitol other edible polyhydric alcohols, and mixtures thereof, at a level of from about 5% to about 70%, by weight of the compositions.

Titanium dioxide may also be added to the present compositions. Titanium dioxide is a white powder which adds pigment to the compositions. Titanium dioxide generally comprises from about 0.25% about 1% by weight of the compositions.

Water is also present in the toothpaste compositions 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 about 5% to about 40%, preferably from about 20% to about 35%, by weight of the 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.

The pH of the present toothpaste compositions is preferably adjusted through the use of buffering agents. Buffering agents, as used herein, refer to agents that can be used to maintain the pH of the present compositions to a range of above about pH 8 as desired for addition of the sodium bicarbonate. These agents include trisodium phosphate, sodium hydroxide and sodium carbonate. Sodium carbonate is preferred at a level of from about 0.5% to about 2% by weight of the present compositions.

An abrasive polishing material may also be included. The abrasive polishing material contemplated for use in the compositions of 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 paniculate condensation products of urea and formaldehyde, and others such as disclosed by Cooley et al. in U.S. Patent 3,070,510, December 25, 1962, incorporated herein by reference. Mixtures of abrasives may also be used.

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 dentin. The silica abrasive polishing materials useful herein, as well as other abrasives, generally have an average particle size ranging between about 0.1 and 30 microns, preferably 5 and 15 microns. The silica 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 March 2, 1970 and DiGiulio, U.S. Patent 3,862,307, June 21, 1975, both incorporated herein by reference. Preferred are the silica xerogels marketed under the tradename "Syloid" by 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 U.S. Patent 4,340,583, July 29, 1982, incorporated herein by reference.

The abrasive in the toothpaste compositions described herein is preferably present at a level of from about 6% to 70%, more preferably from about 10% to about 40% if including Calpyro abrasive.

The present toothpaste compositions can also contain surfactants. Suitable surfactants 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 agents are disclosed by Gieske et al. in U.S. Patent 4,051,234, September 27, 1977, incorporated herein by reference. Sodium alkyl sulfate and polyethylene glycol are preferred for use in the present process and compositions at a level of from about 0.5% to about 5% by weight of the compositions.

Flavoring agents can also be added to the present 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 toothpastes at levels of from about 0.005% to about 2% by weight of the composition.

The present invention compositions may also contain optional pharmaceutical agents (e.g., triclosan) and other tartar control agents. Optional tartar control agents include such known materials as 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., and U.S. Patent 4,515,772 to Parran et al. the disclosures of which are incorporated herein by reference in their entirety; as well as, e.g., polyamino propane sulfonic acid (AMPS)], polyphosphates (e.g., pyrophosphates such as sodium pyrophosphate and others disclosed in the above '977 patent,tripolyphosphate, hexametaphosphate), diphos- phonates (e.g., EHDP; AHP), polypeptides (such as polyaspartic and polyglutamic acids), and mixtures thereof.

Other suitable oral care product carriers other than toothpastes may also be used. Included are mouthwashes, prophylaxis pastes, and the like. Conventional mouthwash composition components can comprise the carrier for the active agents of the present invention. Mouthwashes generally comprise from about 20:1 to about 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 detnifrices. 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 0% 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. Product Use

The compositions of the present invention are used in a manner consistent with regular oral care practices.

Method of Manufacturing: The compositions of the present invention may be produced in any number of ways including those described in the U.S. Patents referred to above.

The following example further describes and demonstrates embodiments within the scope of the present invention. This example is given solely for the purpose of illustration and is not to be construed as a limitation of the present invention as many variations thereof are possible without departing from the spirit and scope.

EXAMPLE Ingredient

Sodium bicarbonate 20.000

Silica 18.000

Glycerin 15.000

Sorbitol (70%) 11.161

Tetrasodium pyrophosphate 5.045

Sodium alkyl sulfate (27.9%) 4.000

PEG-6 3.000

Sodium carbonate 1.250

Flavor 1.000

Carboxymethylcellulose 0.700

Sodium saccharin 0.528

Titanium dioxide 0.350

Sodium fluoride 0.243

FD&C Blue No. 1 0.000

Water q.s. 100%

100.000

Claims

1. An oral composition comprising a soluble fluoride ion source capable of providing from about 250 to about 800 ppm of free fluoride ions in the composition and from about 10% to about 30% of sodium bicarbonate.

2. A composition according to Claim 1 which is a toothpaste wherein water is present in an amount of from about 15% to about 35%.

3. A toothpaste composition according to either of Claims 1 or 2 wherein the fluoride ion source is selected from the group consisting of sodium fluoride, stannous fluoride, indium fluoride, sodium monofluorophosphate.

4. A toothpaste composition according to any of Claims 1-3 which in addition contains an anticalculus agent.

5. A toothpaste composition according to any of Claims 1-4 which in addition contains an agent selected from the group consisting of surfactants, flavoring agents, dyes, thickening agents, antibacterial agents, and mixtures thereof.

6. A toothpaste composition comprising sodium bicarbonate, a soluble fluoride ion source capable of providing from about 250 to about 800 ppm of free fluoride ions in the composition, a soluble pyrophosphate salt and water.

7. A toothpaste composition according to Claim 6 which contains from about 15 to about 35% of water and the fluoride ion level is from about 500 to about 700 ppm.

8. A toothpaste composition according to either of Claims 6-7 which in addition contains an agent selected from the group consisting of surfactants, flavoring agents, dyes, thickening agents, antibacterial agents, such as triclosan humectants mixtures thereof.

9. A toothpaste composition according to any of Claims 6-8 wherein a humectant is xylitol present at a level of from about 5% to about 70%.

10. A toothpaste composition according to any of Claims 6-9 wherein the anticalculus agent is a zinc salt.

11. A composition according to Claim 1 which is a mouthwash.

12. A method of remineralizing dental enamel by brushing the teeth of a person in need of said remineralization with a composition according to Claim 1.

13. A method of remineralizing dental enamel by brushing the teeth of a person in need of said remineralization with a composition according to Claim 6.