IE841793L - Dentifrice - Google Patents

Abstract

A stable antiplaque dentifrice with improved foaming and fluoride chemical stability containing an antiplaque quaternary ammonium compound, a betaine surfactant to improve foaming without inactivating the antibacterial and antiplaque activity of the quaternary ammonium compound, a humectant selected from the group consisting of polyethylene glycol, sorbitol and mixtures thereof, a nonionic gelling agent, such as hydroxyethylcellulose, and preferably a fluorine-containing compound capable of providing a fluoride ion, in an aqueous vehicle containing a dental abrasive. The sorbitol component, which stabilises the betaine quaternary ammonium system, also improves long term fluoride chemical stability of the dentifrice. In a sole polyethylene glycol humectant, a small amount of glycerin, as low as 1%, may be utilised to improve long term fluoride stability, without adversely affecting the cosmetic stability of the dentifrice. [GB2143129A]

Description

57HVU The present invention relates to an antiplaque 5. dentifrice containing a quaternary active ingredient and at least 1.5% and up to 2% betaine surfactant by weight, such as cocoamidopropylbetaine, lauramido-propylbetaine or cocobetaine, which enhances foaming and does not inactivate the antibacterial activity 10. of the quaternary compound. Nonionic surfactants fail to afford sufficient foaming, and nonionic surfactants inactivate the quaternary antibacterial activity. Carbowax 600 (polyethylene glycol) and/or sorbitol replace propylene glycol and glycerin as humectant 15. in order to afford stability to the betaine-containing composition. Also, carboxymethyl cellulose is preferably avoided because large organic molecules deactivate the quaternary compound. Nonionic gums such as hydroxy-ethylcellulose are used as gelling/thickening agent 20. for the dental cream. More specifically, this composition is free of anionic and nonionic surfactants and contains only a minimal amount of glycerin, 1-10% and preferably 5-7% by weight as a fluoride stabiliser (when a fluoride compound is used) in a sole poly-25. ethylene glycol humectant-containing composition.

It has beer^ found that the addition of a betaine surfactant to an antiplaque dental formulation based on quaternary active ingredients, improves the foaming characteristics thereof, without deactivating the 30. quaternary antimicrobial activity. It has additionally 2 been found that humectants other than glycerin are required in the betaine system to effect cosmetic stability, specifically polyethylene glycol and/or sorbitol. The limitation of the gelling/thickening 5. agent to nonionic gums such as hydroxyethylcellulose is also a necessary expedient.

The ability of quaternary ammonium compounds to inhibit the formation of dental plaque is well documented. These compounds, however, present a 10. problem when formulated in a dentifrice in that they are deactivated by traditional anionic surfactants such as sodium lauryl sulphate. Stable, clinically effective dental formulations have been made with quaternary ammonium compounds and nonionic surfactants 15. but these formulations are very poor foamers and result in inferior products. Compositions containing antiplaque quaternary ammonium compounds and nonionic surfactants are disclosed in U.S. Patents Specification Nos. % 4,080,441, 4,110,429, 4,118,472, 4,118,473, 4,118,475, 20. 4,118,476 and British Patent No. 1,573,356.

U.S. Patent Specification No. 4,161,518 discloses a dentifrice composition for inhibiting plaque formation containing 0.05-1% by weight of a quaternary ammonium organosiloxane as the active antibacterial agent in 25. a suitable vehicle containing suitable polishing agents, fluoride compounds, anionic surfactants, flavouring and sweetening agents, thickening agents such as carboxymethylcellulose, humectants such as glycerin, sorbitol and other polyhydric alcohols. 30. U.S. Patent Specification No. 3,988,435 discloses pharma 3 ceutical compositions including a dentifrice containing a quaternary ammonium dihydrochalcone glucoside as the antibacterial agent having a sweet taste, as well as abrasives, surfactants including nonionics and 5. "derivatives of fatty amines with betaine structures," swelling, gelling or thickening agents such as hydroxy-alkylcellulose particularly hydroxyethylcellulose, polyethylene glycols, polypropylene glycols, etc., humectants such as sorbitol, mannitol, glycerin, 10. propylene glycol, colourants, and flavours.

All of aforesaid cited patents simply list the conventional additives useful in dentifrice compositions. There is no disclosure of the use of the betaine as the exclusive surfactant in the production 15. of a high foaming dentifrice. There is also no disclosure nor recognition of the necessity to limit the humectant to polyethylene glycol and/or sorbitol, and the thickening agent to nonionic gums such as hydroxyethylcellulose, in order to obtain a cosmeti-20. cally stable dentifrice in a betaine-quaternary ammonium system.

U.S. Patent Specification No. 4,363,795 and its counterpart International Patent Publication No. WO 80/00057 to Wahlstam disclose a cleaning agent for dentine sur-25. faces containing a quaternary ammonium compound, an ampholytic tenside which may be an imidazoline or a betaine and a sequestering agent of the aminocar-boxylic acid type which has a synergistic effect as to the antibacterial properties of the treating 30. solution. All the Examples are in the form of 4 cleaning solutions. There is no mention of dental creams, nor the use of humectants and thickening agents.

U.S. Patent Specification No. 4,130,637 discloses a specific group of betaine compounds, or a mixture of the said 5. betaine and its corresponding carboxylic acid quaternary ammonium salt in a 9:1 ratio, as non-staining antimicrobial antiplaque agents in a dentifrice vehicle containing the aforelisted conventional humectants and gelling agents, and a nonionic surfactant. This patent 10. fails to disclose the necessity of using a betaine surfactant exclusively, the specific nonionic gelling agent hydroxyethylcellulose and the specific humectant polyethylene glycol and/or sorbitol, in order to obtain a stable, high foaming quaternary-containing antiplaque 15. dentifrice.

U.S. Patent Specification Nos. 4,117,107 and 4,117,108 also disclose a specific group of betaine compounds and their salts as antiplaque agents in a dentifrice vehicle containing the conventional humectants and 20. gelling agents, as well as anionic/nonionic surfactants. There is no disclosure of an antibacterial quaternary ammonium compound, and a betaine surfactant exclusively. There is also no recognition of the specificity of humectant and gelling agent and the exclusion 25. of anionic/nonionic surfactants in a quaternary- betaine system, which is necessary in order to obtain a stable high foaming antiplaque dentifrice.

Thus, none of the above cited prior art discloses a cosmetically stable antiplaque dentifrice 30. with improved foaming and fluoride stability containing as the essential ingredients a cationic quaternary ammonium antiplaque compound, a zwitterionic betaine surfactant, a humectant compatible with the cationic antiplaque agent selected from the group consisting 5. of polyethylene glycol and sorbitol, and the nonionic gelling agent hydroxyethylcellulose, in an aqueous vehicle containing a dental abrasive. Nor is there a prior art disclosure of the sorbitol humectant improving long term fluoride stability, nor the com-10. bination of small amounts of glycerin in a polyethylene glycol humectant improving long term fluoride stability.

We have now found that dental cream formulations containing antiplaque quaternary ammonium compounds may be stabilised and provide better foaming when betaine 15. type surfactants replace the traditional anionic and nonionic surfactants. Humectants such as polyethylene glycol and sorbitol must replace the conventional glycerin for better cosmetic stability of the product. However, a small amount of glycerin may be used to 20. chemically stabilise the fluoride-containing compound in a sole polyethylene glycol humectant. Nonionic gums such as hydroxyethylcellulose replace the anionic carboxymethylcellulose gelling agent which also has the potential to deactivate the quaternary compound. 25. The present invention aims to provide a better foaming antiplaque dentifrice based on quaternary active ingredients by the incorporation of a zwitterionic betaine surfactant as the foaming agent.

The present invention also aims to provide a 30. cosmetically stable foaming antiplaque dentifrice 6 containing polyethylene glycol and/or sorbitol as humectant which is compatible with the betaine and the quaternary active ingredients.

This invention also aims to provide a stable 5 foaming antiplaque dentifrice containing the nonionic gum, hydroxyethylcellulose, as gelling agent to stabilise the betaine quaternary ammonium system and to prevent deactivation of the quaternary active ingredient by the anionic sites in molecules of carboxymethylcellulose. 10 This invention also aims to provide a cosmetic (physical) and chemically stable foaming antiplaque dentifrice containing a fluoride-providing compound and sorbitol or minimal amounts of glycerin, (1-10% by weight) as stabilising agents for the fluoride-providing compound, 15 without adversely affecting cosmetic stability of the dentifrice.

According to the present invention a stable antiplaque dentifrice with improved foaming which is free of nonionic and anionic surfactants, comprises as the 20 essential ingredients, an effective amount of an antiplaque quaternary ammonium compound, at least 1.5% by weight of a betaine surfactant, the betaine surfactant being the sole surfactant species, a humectant selected from the group consisting of polyethylene glycol, sorbitol 25 and mixtures thereof, a nonionic gelling agent such as hydroxyethylcellulose and preferably a fluroide-providing compound, in an aqueous vehicle containing a dental abrasive.

More specifically, the present invention 30 relates to a stable antiplaque dentifrice formulation with improved foaming and fluoride stability which is free of nonionic and anionic surfactants, comprising an effective antimicrobial amount of a 7 quaternary ammonium compound, at least 1.5% by weight e.g. about 1.5-2% by weight of a betaine surfactant, preferably about 0.05-2% by weight of a fluoride-providing compound, and sorbitol or 1 to 10% by weight of glycerine as a 5 stabilizer for the fluoride providing compound, preferably about 20-30% by weight of a humectant selected from the group consisting of polyethylene, glycol, sorbitol and mixtures thereof, and a nonionic gelling agent, e.g. about 0.5-2% by weight of hydroxyethylcellulose, preferably in 10 an aqueous vehicle containing about 40-60% by weight of water-insoluble dental abrasive. The sorbitol component, which stabilises the betaine-quaternary ammonium system, also improves the long term fluoride chemical stability of the dentifrice. When the sole humectant is polyethylene 15 glycol, a small amount of glycerin, as low as 1%, may be utilised to improve long term fluoride stability, without adversely affecting the cosmetic stability of the dentifrice.

Cationic antibacterial materials are well known 20 in the art. See, for instance the section on "Quaternary Ammonium and Related Compounds" in the article on "Antiseptics and Disinfectants" in Kirk-Othmer Encyclopedia of Chemical Technology, 2nd Edition (Volume 2, pages 632-635), incorporated herein by reference. 25 Cationic materials which possess anti- bacterial activity (i.e. are germicides) are used against bacteria and have been used in oral compositions to counter plaque formation caused by bacteria in the oral cavity.

Among the most common of these antibacterial 30 antiplaque quaternary ammonium compounds is benzethonium chloride, also known as Hyamine 1622 or diisobutylphenoxy-ethoxyethyl dimethyl benzyl ammonium 8 chloride, and cetyl pyridinium chloride. In an oral preparation this material is highly effective in promoting oral hygiene by reducing formation of dental plaque and calculus, which is generally accompanied by a reduction in periodontal diseases. Other cationic antibacterial agents of this type are those mentioned, for instance, in U.S. Patent Specification Nos. 2,984,639, 3,325, 3,431,208 and 3,703,583 and British Patent Specification No. 1,319,396.

Other antibacterial antiplaque quaternary ammonium compounds include those in which one or two of the substituents on the quaternary nitrogen has a carbon chain length (typically an alkyl group) of some 8 to 20, typically 10 to 18, carbon atoms while the remaining substituents have a lower number of carbon atoms (typically an alkyl or benzyl group), such as 1 to 7 carbon atoms, typically methyl or ethyl groups. Dodecyl trimethyl ammonium bromide, benzyl dimethyl stearyl ammonium chloride, cetyl pyridinium chloride and quaternised 5-amino-l,3-bis (2-ethylhexyl)-5-methyl hexa hydro-pyrimidine are typical quaternary ammonium antibacterial agents.

The dentifrice formulations of the present invention contain an effective amount of the antiplaque quaternary ammonium compound, preferably about 0.01-5%, and most preferably 0.025-1% by weight of the composition.

The ability of quaternary ammonium compounds to inhibit the formation of dental plaque is well known. However, they are deactivated by the anionic surfactants such as sodium lauryl sulphate conventionally used in dentifrice formulations. The substitution of nonionic surfactants for the anionic surfactants eliminates the deactivation problem but results in products with poor foaming.

The incorporation of betaine surfactants into antiplaque dental formulations based on quaternary 5. active ingredients unexpectedly improves the foaming of these formulations without deactivating the quaternary antibacterial agents.

The betaine component of present dentifrice composition has the general formula: .

R2 1 '+ 4 R-N-R-COO A3 . wherein R"'" represents an alkyl group having 10 to about 20 carbon atoms, preferably 12 to 16 carbon atoms or the amido radical: 0 H II t . R-C-N-(CH2) wherein R represents an alkyl group having about 10 to 20 carbon atoms and a is the integer 1 to 3; .4 2 3 R and R each represent an alkyl group having 1 to . 3 carbon atoms and preferably 1 carbon atom; R represents an alkylene or hydroxyalkylene group having from 1 to 4 carbon atoms and, optionally, one hydroxy1 group. Typical alkyldimethyl betaines include decyl betaine or 2-(N-decyl-N,N-dimethylammonio) acetate, 3o. coco betaine or 2-(N-coco-N,N-dimethylammonio) acetate, myristyl betaine, palmityl betaine, lauryl betaine, cetyl betaine and stearyl betaine. The amidobetaines similarly include cocoamidoethyl betaine, cocoamido-propyl betaine and lauramidopropyl betaine. 5. The betaines, which are zwitterionic materials, function as a foaming agent in the quaternary-containing dentifrice compositions of the present invention. They act cationically over a wide pH range, but do not deactivate the quaternary anti-10. microbial activity. This is shown by in vitro tests using wool swatches, which simulate human skin and oral tissue, as the absorptive material in the Red 80 Stain test, J. Soc. Cosmet, Chem. 21' 271-278 (Sept., Oct. 1980). Wool has the same type of absorptive 15. properties as oral tissue due to similar isoelectric and isoionic points.

Using the Red 80 Dye Test, the following experiment illustrates that the betaine surfactant does not deactivate the quaternary. The Red 80 Stain 20. Test was performed using a solution of cocoamidopropyl betaine alone, benzethonium chloride alone, and a mixture of cocoamidopropylbetaine and benzethonium chloride. The degree of staining of the wool swatches treated with benzethonium chloride alone and the mix-25. ture of benzethonium chloride and betaine was nearly equal, and both were stained darker than the cocoamidopropyl betaine treated swatch. This indicates that benzethonium chloride is a "stronger" cationic compound than the betaine i.e. it has a greater attraction to 30. the wool than the betaine, indicating that the betaine 11 does not deactivate the benzethonium chloride.

However, wool swatches treated with a mixture of benzethonium chloride and the anionic surfactant, sodium lauryl sulphate, exhibit no staining (no red 5. colour retention) indicating complete deactivation of the benzethonium chloride by the anionic surfactant.

The degree of staining of the wool swatches treated with a mixture of benzethonium chloride and the nonionic surfactant, polyoxyethylene (20 moles 10. ethylene oxide) sorbitan di-iso stearate, was substantially equal to that of the benzethonium chloride alone. This indicates that the benzethonium chloride is not deactivated by the nonionic surfactant.

In addition to the non-interference exhibited 15. by the betaines with the quaternary activity, laboratory foam tests have shown that formulations containing both the quaternary ammonium compound and the betaine, foam 2 to 3 times better than the nonionic quaternary ammonium formulations. The foam index for nonionic 20. quaternary ammonium compositions is about 20, whereas the foam index for betaine quaternary ammonium compositions is about 40-60. The foam test used herein comprises placing 1 gram of the test dentifrice in 10 ml of 175 PPM water at 90°F (32°C) in a 100 ml 25. graduated cylinder, shaking for 15 seconds and reading the foam height.

The zwitterionic betaines are completely compatible with the quaternary antimicrobial antiplaque agents, and impart detersive and improved foaming 30. properties to the quaternary-containing dentifrice 12 composition without deactivating the antimicrobial properties thereof. The amount of betaine effective in the production of improved foaming may be varied from about 1.5-2% active ingredient by weight of the 5. tbtal formulation. Greater amounts of betaine adversely affect the taste of the dentifrice.

Cosmetic problems of stability are incurred with all zwitterionic-containing dentifrices, such as crimp leakage of flavour. The flavour oozes and is 10. not solubilised in the zwitterionic surfactant.

Accordingly, in order to effect cosmetic (physical) stability of the betaine system, a specific group of humectants which includes polyethylene glycol, sorbitol or mixtures thereof must be used. 15. Glycerin and propylene glycol alone provide insufficient cosmetic stability to the betaine system. The humectant system constitutes about 20-30% by weight and preferably 20-25% by weight of the dentifrice and is selected from the group con-20. sisting of polyethylene glycol, sorbitol and mixtures thereof.

Another essential ingredient in dentifrice compositions of the present invention is a gelling agent which is a nonionic gum, in an amount up to 25. 5% by weight and preferably about 0.5-2%. It has been found that large organic anionic molecules such as carboxymethylcellulose have the potential to deactivate the quaternary antibacterial activity. Accordingly, hydroxyethylcellulose, which is a 30. nonionic small organic molecule, effects a stable 13 pituitous gel in the betaine quaternary ammonium system of the present invention, and is the preferred gelling agent. Other nonionic gelling agents may be used such as hydroxymethylcellulose.

It has been found that only by utilising the specific combination of ingredients of betaine, polyethylene glycol and/or sorbitol humectant and nonionic gelling agent, can a stable antiplaque dentifrice with improved foaming based on the quaternary antibacterial compounds, be obtained.

The fluoride-providing compounds, which are preferably additional ingredients in dentifrice compositions of the present invention, are characterised by their ability to release fluoride ions in water and by substantial freedom from reaction with other compounds of the dentifrice. Among these materials are inorganic fluoride salts, such as soluble alkali metal, alkaline earth metal and heavy metal salts, for example, sodium fluoride, potassium fluoride, ammonium fluoride, lead fluoride, a copper fluoride such as cuprous fluoride, zinc fluoride, a tin fluoride such as stannic fluoride or stannous chorofluoride, barium fluoride, sodium fluorosilicate, ammonium fluorosilicate, sodium fluorozirconate, sodium monofluorophosphate, aluminium mono- and di-fluorophosphate, and fluorinated sodium calcium pyrophosphate. Alkali metal and tin fluorides, such as sodium and stannous fluorides, sodium mono-fluorophosphate and mixtures thereof, are preferred.

The amount of the fluoride-providing compound is dependent to some extent, upon the type of compound, 14 its solubility, and the dentifrice, but it must be a nontoxic amount. In a solid oral preparation, such as a toothpaste or dental cream, an amount of such compound which releases a maximum of 1% by weight of the prepara-5. tion is considered satisfactory. Any suitable minimum amount of such compound may be used, but it is preferable to employ sufficient compound to release from 0.005% to 1%, and preferably about 0.1% of fluoride ion. Typically, in the cases of alkali metal fluorides 10. and stannous fluoride, this component is present in an amount up to 2% by weight, based on the weight of the preparation, and preferably in the range of from 0.05% to 1%. In the case of sodium monofluorophosphate, the compound may be present in an amount up to 7.6% by 15. weight, more typically 0.76%.

It has additionally been found that the long term chemical fluoride stability in a sorbitol based humectant or a mixed surfactant system containing polyethylene glycol and at least 5% sorbitol is markedly 20. improved over a polyethylene glycol based humectant, wherein its fluoride stability is marginal but acceptable. However, the use of small amounts of glycerin, about 1-10% and preferably 5-7% by weight in a polyethylene glycol based humectant markedly 25. improved long term fluoride stability without adversely affecting the cosmetic stability of present dentifrice formulation. The glycerin component herein functions as, and is used as a chemical stabiliser for the fluoride ingredient only when polyethylene glycol 30. is used as the sole humectant.

Based on the three week results of the 120°F (49°C) aging study, 5% glycerin improves the fluoride stability 25% without adversely affecting cosmetic stability. The mechanistic reason why the presence 5. of some glycerin improves the fluoride stability is unclear. Fluoride stability data after 12 weeks at 100°F (37°C) further confirms the significant improvement with the use of small amounts of glycerin in the dentifrice. Table 1 clearly shows this improved 10. fluoride stability in a polyethylene glycol humectant system.

TABLE 1 Soluble Fluoride Content Glycerin: Polyethylene 3 wks r\ 6 wks 9 wks n 12 wks Glycol Initial @ 100 F 0 100 F @ 100 F @ 100°F 0:20 0.093 0.077 0.068 0. 06 3 0.057 1:19 0.088 0.081 0.074 0. 066 0.066 3:17 0.093 0.082 0.074 0. 069 0.067 :15 0.093 0.081 0.077 0. 071 0.070 :10 0.094 0.086 0.083 0. 080 0.077 It has also been found that increase in the 25. glycerin content results in decreases in pH as shown in Table 2. 16 TABLE 2 Glycerin:Polyethylene pH Glycol 9 wks @ 120°F . 0:20 9.8 1:19 9.7 3:17 9.4 :15 9.4 :10 8.9 .

The. dentifrice of the present invention, which is a toothpaste or dental cream, contains conventional water-insoluble polishing materials or dental abrasives, in amounts from about 20-75% and preferably about 40-15. 60% by weight of the total formulation. Suitable examples of dental abrasives or polishing materials include sodium metaphosphate, potassium metaphosphate, tricalcium phosphate, dihydrated calcium phosphate, anhydrous dicalcium phosphate, calcium pyrophosphate, 20. magnesium orthophosphate, trimagnesium phosphate, calcium carbonate, alumina, hydrated alumina, aluminium silicate, zirconium silicates, silica, bentonite, and mixtures thereof, such as a mixture of hydrated alumina and calcined alumina.

The dentifrice of the present invention may 25. also contain conventional additional ingredients such as colouring or whitening agents, preservatives, flavouring or sweetening materials, and ammoniated materials such as monoammonium glycyrrhizinate. These additional ingredients may each be added to the denti-30. frice in minimal amounts of up to 5% by weight, and 17 preferably up to 1%, provided they do not interfere with the foaming, antiplaque and stability properties of the finished product.

The dentifrice of the present invention is 5. prepared by conventional methods of making toothpaste and/or dental creams. More specifically, a toothpaste may be prepared by forming a gel with hydroxyethylcellulose and water, adding thereto with mixing the powdered materials including the fluoride compound 10. and humectant, followed by the addition with mixing of polishing agent and then the betaine and flavour, and inserting the final mixture in the toothpaste tube.

In the practice of this invention to promote 15. oral hygiene, the dentifrice according to this invention is applied regularly to dental enamel by brushing the teeth for 30-90 seconds at least once daily.

The invention may be put into practice in various ways and a number of specific embodiments 20. will be described to illustrate the invention with reference to the following Examples.

The compositions are prepared in the usual manner and all amounts and proportions referred to herein and in the appended claims are by weight unless 25. otherwise indicated.

EXAMPLE 1 A dentifrice having the composition given in Table 3 is made up. 18 TABLE 3 Ingredients Hydroxyethylcellulose 5. Carbowax 600"^" Na Saccharin MFP2 CAB3 (35% A.I.) Dicalcium Phosphate 10. BZC14 D.I. H20 Flavour Notes on Table 3 .

^"Polyethylene glycol, mol. weight 600 2 Sodium monofluorophosphate 3 Cocoamidopropyl betaine 4 Benzethonium chloride .

The hydroxyethylcellulose and water are premixed for 10 minutes to form a gel. The powdered materials MFP, BZC1 and saccharin, and the Carbowax humectant are added to the gel and mixed for 10 to 20 minutes. 25. The gelled mixture is added to dicalcium phosphate and mixed for 20 minutes at speed 8 in a Ross agitator. The betaine and flavour is added to the mixture and mixed for 5 minutes at speed 6 in the Ross agitator. The resultant dental cream which is cosmetically 30. attractive is inserted into tubes. 1. 0 . 0 0. 2 0. 76 3. 49. 0 0.

• CM 04 l. 0 19 Aging tests performed on this product in lines tubes at room teperature, at 40°F (4.5°C) and 100°F (38°C) for 9 weeks, and in unlined tubes at 120°F (49°C) for 9 weeks, shewed it to have excellent cos-5. metic stability.

EXAMPLE 2 A dentifrice having the composition given in Table 4 is made up.

TABLE 4 Ingredients % Hydroxyethylcellulose 1.1 Carbowax 600 .0 Na Saccharin 0.2 MFP 0. 76 CAB (35% A.I.) .7 Dicalcium Phosphate 00 • BZC1 0.5 H2° 24.04 Flavour 1.0 .

This dental cream is prepared in accordance with the procedure of Example 1. This product has a pH of 6.7 and a foam height of 55, but does not taste good.

. EXAMPLE 3 A dentifrice having the composition given in Table 5 is made up.

TABLE 5 Ingredients Hi Sweet peppermint 1.0 MAG1 0.1 . BZC1 0.5 MFP 0.76 Na Saccharin 0.2 H20 23.44 PEG 6002 20.0 10. Natrosol 3 (Registered Trade Mark) i.o Dicalcium phosphate 49.0 CAB (30% A.I.) 4.0 Notes on Table 5 .

^Monoammonium glycyrrhizinate 2 Polyethylene glycol, molecular weight 600 3 Hydroxyethylcellulose . This dental cream is prepared according to the procedure of Example 1, except that the pH is adjusted to 8.5 with dilute NaOH for hydration purposes, after the polyethylene glycol is added to the gelled premix. The resultant cream looks good, has a foam 25. height of 38-40, and shows excellent stability using aging tests over a period of 12 weeks at 100°F (38°C) as well as at 140°F (60°C) in unlined tubes for 3 weeks.

EXAMPLE 4 - THIS IS A COMPARISON EXAMPLE Example 3 is repeated except that glycerin . replaces the polyethylene glycol humectant. This 21 product gives a foam height of 46, but shows trace separation in 3 days at 140°F (60°C) and a wetness and separation at the neck of the tube at 120°F (49°C) in 3 weeks. This product is cosmetically unstable.

. EXAMPLE 5 A dentifrice having the composition given in Table 6 is made up.

TABLE 6 Ingredients % H2° 21.14 Natrosol 1. 3 Propylene glycol .0 Na Saccharin 0.2 BZC1 0.5 MAG 0. 1 MFP 0. 76 Dicalcium "phosphate 50.0 CAB (30% A.I.) .0 Flavour 1.0 .

This dental cream is prepared according to the procedure of Example 1 except that the propylene glycol humectant is mixed with the premix gel for only 10 minutes. The resulting product is good in appearance 25. and foaming with a foam height of 44. However, it's instability is clearly evident by separation, wetness along the ribbon and clip leakage in 3 weeks at 8°F (-13°C) and 40°F (4.5°C) and slight yellowing at 110°F (43°C) and 120°F (60°C) within 3 weeks. 22 .

, EXAMPLE 6 A dentifrice having the composition given in Table 7 is made up.

TABLE 7 Ingredients % H2° 19.68 Natrosol 1.1 Carbowax 600 .0 Na Saccharin 0.2 BZC1 0.5 MAG 0.1 MFP 0. 76 Dicalcium phosphate 50.0 CAB (30% A.I.) 6.66 Flavour 1.0 .

This dental cream is prepared according to the procedure of Example 1.

The resulting product is slightly thick but exhibits good foaming and stability. 20. EXAMPLE 7 A dentifrice having the composition given in Table 8 is made up.

TABLE 8 Ingredients % . H20 21.34 Natrosol 1.1 Carbowax 600 20.0 Na Saccharin 0.2 BZC1 0.5 . MAG 0.1 23 TABLE 8 (Cont.) Ingredients % MFP 0.76 Ca2P2071 50.0 5. CAB (30% A.I.) 5.0 Flavour 1.0 Notes on Table 8 ^Calcium pyrophosphate .

This dental cream is prepared according to the procedure of Example 1.

The resulting cream is thick and grainy, which may be due to the coarseness of the calcium pyrophos- phate dental abrasive.

EXAMPLE 8 A dentifrice having the composition given in Table 9 is made up.

TABLE 9 Ingredients % h20 17.68 Natrosol 1.1 Carbowax 600 .0 Na Saccharin o. 2 BZC1 0.5 MAG 0.1 MFP 0.76 Dicalcium phosphate dihydrate 42.0 Anhydrous Dicalcium phosphate .0 CAB (30% A.I.) 6.66 Flavour 1.0 24 , .

EXAMPLE 9 A dentifrice having the composition given in Table 10 is made up.

TABLE 10 .

Ingredients % Carbowax 600 .0 Natrosol 1. 1 Na Saccharin 0.2 MAG 0.1 .

BZC1 0.5 H2° 17. 68 MFP O * -J Hydrated Alumina 42.0 Calcined Alumina .0 .

Cocoamidopropyl betaine (30% A.I.) 6.66 Flavour 1.0 pH 8.3 This product shows complete stability after aging for 9 weeks at room temperature, 40°F (4.5°C), 100°F (38°C) and 120°F (49°C).

EXAMPLES 10 and 11 Dentifrices having the compositions given in Table 11 are made up.

TABLE 11 , Ingredients PEG 600 Natrosol Na Saccharin Ex. 10 % .0 1.1 0. 3 Ex. 11 % .0 1.3 0. 3 TABLE 11 (Cont.) Ex. 10 Ex. 11 Ingredients % % Hydrated Alumina 42.0 42.0 .

Calcined Alumina .0 .0 CAB (30% A.I.) .0 .0 MFP 0. 76 0. 76 Flavour 1.0 1.0 H20 D.I. 19.27 19.27 .

BZC1 0.5 0.5 Red 40 (1% solution) 0.07 0.07 EXAMPLE 12 A dentifrice having the composition given in 15. Table 12 is made up.

TABLE 12 Ingredients Sorbitol (70% aqueous solution) 28.0 Natrosol 1. 1 Na Saccharin 0. 3 BZC1 0.5 MFP 0. 76 Alumina 42.0 Calcined Alumina .0 CAB (30% A.I.) .0 Flavour 1.0 H_0 11. 34 Initial pH 7.4 3 weeks pH 7.5 30. 6 weeks pH 7.6 26 This product exhibits complete stability at 8°F (-13°C) and 40°F (4.5°C) for a period of 9 weeks but slight wet cap at 110°F (4 3°C) and 120°F (4 9°C) after 3-9 weeks. In addition to the good physical stability 5. of this product, the active ingredient content (ionic fluoride and the benzethonium chloride) remains stable as evidenced by the substantially stable pH.

EXAMPLE 13 A dentifrice having the composition given in 10. Table 13 is made up.

TABLE 13 , Ingredients % H2° 21.14 Natrosol 1. 3 Sorbitol .0 Na Saccharin o. 2 BZC1 o. 5 MAG o. 1 MFP 0. 76 Dicalcium phosphate dihydrate 50.0 CAB (30% A.I.) .0 Flavour 1.0 The resultant cream exhibits a foam height 25. of 42 and no flavour separation after 9 weeks at 120°F (49°C). This product is completely stable at 8°F (-13°C) and 40°F (4.5°C) for a period of 9 weeks, but exhibits traces of a wet cap at 110 F (43°C) and 120°F (49°C) after 3 to 9 weeks. 27 EXAMPLE 14 A dentifrice having the composition given in Table 14 is made up.

TABLE 14 . Ingredients % Natrosol 1.1 Na Saccharin 0. 3 BZci 0.5 MFP 0.76 . Carbowax 600 10.0 Sorbitol (70%) 10.0 1^0 deionized 19.34 Hydrated Alumina 10.0 Calcined Alumina 42.0 15. Flavour 1.0 CAB (30% A.I.) 5.0 EXAMPLE 15 A dentifrice having the composition given in 20. Table 15 is made up.

TABLE 15 Ingredients % Natrosol 1.1 Na Saccharin 0. 3 MFP 0.76 BZCI 0.5 Carbowac 600 .0 Sorbitol (70%) .0 h2o 19. 34 Hydrated Alumina 42.00 28 .

TABLE 15 (Cont.) Ingredients Calcined Alumina Flavour CAB (30% A.I.) .0 1.0 5.0 , , , , This product which contains 5% sorbitol, exhibits 84% soluble fluoride recovery at 12 weeks at 100°F (38°C), as compared to 61% fluoride recovery (an acceptable level) for the systems using polyethylene glycol alone as the humectant under the same conditions, e.g. Examples 1 to 11. This indicates that the presence of sorbitol, in amounts as low as 5% (70% A.I.), provides superior fluoride stability.

EXAMPLES 16 - 20 Dentifrices having the compositions given in Table 16 are made up.

TABLE 16 16 Example 17 18 19 1.10 1.10 .

Ingredients % % Polyethylene Glycol (Carbowax 600) 15 17 Glycerin 5 3 Hydroxyethyl cellulose Sodium Monofluorophosphate 0.76 0.76 Sodium Saccharin 0.30 0.30 Benzethonium chloride 0.50 0.50 Hydrated Alumina 42 42 Calcined Alumina 10 10 19 1 1.10 0.76 0. 30 0.50 42 10 % 1.10 0.76 0. 30 0.50 42 10 % 20 1.10 0. 76 0. 30 0.50 42 10 29 TABLE 16 (Cont.) Example 16 17 18 19 20 Ingredients % %_ % % % CAB (30% A.I.) 5 5 5 5 5 Flavour 11111 Water 19.34 19.34 19.34 19.34 19.34 Fl" content1 0.07 0.067 0.066 0.077 0.057 Note on Table 16 1Chemical stability of the above formulations after accelerated aging for 12 weeks at 100°F (38°C) as determined by the percentage of Fl content.

All the above formulations are effective against 1 " plaque related bacteria while possessing improved foaming characteristics, cosmetic stability and chemical stability. The presence of a small amount of glycerin, as low as 1% by weight, enhances the chemical stability of the fluoride in the polyethylene glycol humectant- containing dentifrice over the acceptable fluoride stability in the absence of glycerin (Example 20).

Variations in the above formulations may be made. For example, other betaines such as lauramido-propyl betaine, coco betaine and the like may be sub- stituted for the cocoamidopropyl betaine in the examples. Similarly, other abrasives may be substituted for the specific abrasives in the examples. Likewise, other fluoride-containing compounds such as sodium fluoride or potassium fluoride, may be substituted for the sodium monofluorophosphate in the specific examples.

Claims (15)

1. CLAIMS 1. A stable antiplaque dentifrice with improved foaming which is free of nonionic and anionic surfactants, comprising as the essential ingredients an effective amount of an antiplaque quaternary ammonium compound, at least 1.5% by weight of a betaine surfactant, the betaine surfactant being the sole surfactant species, a humectant selected from the group consisting of polyethylene glycol, sorbitol and mixtures thereof, and a nonionic gelling agent in an aqueous vehicle containing a dental abrasive.

2. A stable antiplaque dentifrice with improved foaming and fluoride stability which is free of nonionic and anionic surfactants, comprising an effective amount of an antiplaque quaternary ammonium compound, at least 1.5% by weight betaine surfactant, a humectant selected from the group consisting of polyethylene glycol, sorbitol and mixtures thereof and a nonionic gelling agent, the betaine surfactant being the sole surfactant species, a fluoride-providing compound and sorbitol or 1 to 10% by weight of glycerine as a stabiliser for the fluoride-providing compound.

3. A dentifrice as claimed in Claim 1, which contains 1.5-2% by weight of the betaine.

4. A dentifrice as claimed in Claim 1 or Claim 2, in which the nonionic gelling agent is hydroxyethylcellulose.

5. A dentifrice as claimed in any one of Claims 1 to 4, which contains 0.5 to 2% by weight of the nonionic gelling agent.

6. A dentifrice as claimed in any one of Claims 1 to 5, containing 20-30% by weight of the humectant.

7. A dentifrice as claimed an any one of Claims 1 to 6, in which the humectant is polyethylene glycol having a molecular weight of about 600.

8. A dentifrice as claimed in any one of Claims 1 to 6, in which the humectant is sorbitol. 31

9. A dentifrice as claimed in any one of Claims 1 to 8, which contains about 40-60% by weight of a water-insoluble dental abrasive.

10. A dentifrice as claimed in any one of 5 Claims 1 to 8, in which the dental abrasive is dicalcium phosphate.

11. A dentifrice as claimed in any one of Claims 1 to 10, in which the antiplaque agent is benzethonium chloride. 10

12. A dentifrice as claimed in any one of Claims 1 to 11, which contains 0.01 to 5% of the antiplaque agent.

13. A dentifrice as claimed in Claim 1 or any of Claims 3 to 12, when dependant on Claim 1, which 15 contains a fluoride-providing compound.

14. A dentifrice as claimed in Claim 2 or Claim 13 containing 0.05-2% by weight of the fluoride-providing compound.

15. A dentifrice as claimed in Claim 13, or 20 claim 14, in which the fluoride-providing compound is sodium monofluorophosphate. 19. A dentifrice as claimed in Claim 2 or Claim 13 when dependant on any one of Claims 1 to 6, in which the humectant is a mixture of polyethylene glycol and at 25 least 5% sorbitol. 17. A dentifrice as claimed in Claim 2 or Claim 13, when dependant on any one of Claims 1 to 6, in which the humectant is polyethylene glycol and 1-10% by weight of glycerin as fluoride stabiliser. 30 18. A dentifrice as claimed in any one of Claims 1 to 17, in which the betaine is cocoamidopropyl betaine. 19. A dentifrice as claimed in any one of Claims 1 to 9, which contains an abrasive, the abrasive 35 being alumina. 20. A dentifrice as claimed in Claim 19, in which the abrasive is a mixture of hydrated alumina and calcined alumina. 32 25. A dentifrice as claimed in Claim 1 substantially as specifically described herein with reference to Examples 1 to 20. Dated this the 12th day of July, 1984. BY: TOMKINS & CO., Applicants' Agents (Signed) 5, Dartmouth Road, DUBLIN 6 33