MXPA00009700A - Aqueous gels comprising ethoxylated polyhydric alcohols - Google Patents

Abstract

There is provided according to the present invention an aqueous gel composition, comprising a) an ethoxylated polyhydric alcohol which comprises a reaction product of an alcohol having 3 to 6 hydroxy groups with ethylene oxide;and b) a gelling agent selected from the group consisting of a polyoxyethylene/polyoxypropylene/polyoxyethylene triblock surfactant having a molecular weight of from 4,000 to 16,000, and wherein the weight of the polyoxyethylene blocks is from 55%to 90%of the weight of the triblock surfactant;a crosslinked polyacrylic thickener;cellulose derivatives;hydrated silicas;and mixtures thereof. When the gelling agent is the triblock surfactants, the ethoxylated polyhydric alcohol comprises the reaction product of the polyhydric alcohol and up to 5 mole equivalents of ethylene oxide per mole equivalent of hydroxyl group in the alcohol.

Description

AQUEOUS GELS COMPRISING POLYHYDRIDE ETOXYL ALCOHOLS Field of the Invention The invention relates to ethoxylates of polyhydric alcohols, and their use in dentifrice gels or personal care compositions.

BACKGROUND OF THE INVENTION The use of ethoxylated polyhydric alcohols, such as glycerol and sorbitol, is known in skin care and pharmaceutical compositions. The use of ethoxylated glycerol in an oral composition at a level of 0.15%, as part of a mixture of lauryl sulfate and sodium / nonionic surfactant, has also been reported. The use of surfactants in three high molecular weight blocks of ethylene oxide and propylene oxide in aqueous gel compositions is well known. See, for example, the discussion in the U.S. patent. No. 5,908,612. With such surfactants in three blocks, aqueous gel compositions can easily be formed with desirable viscosity properties in an appropriate temperature range.

It is also known that such aqueous gel compositions can be made from such surfactants in three blocks in combination with glycerol. A peroxide gel toothpaste which comprises glycerol, a surfactant in three blocks, and a peroxide material has been reported, as has a mouthwash containing a non-ionic surfactant that can be a polyoxyethylene and polyoxypropylene block surfactant , a humectant which can be glycerol, and an antibacterial agent. It is known to use gelling agents with humectants such as glycerol and sorbitol in order to produce aqueous toothpastes. Such gelling agents include crosslinked polyacrylic thickeners, cellulose derivatives, and hydrated silicas. The use of ethoxylated polyhydric alcohols to prepare aqueous dentifrice gels is unknown. Nor have ethoxylated polyhydric alcohols been used as humectants or as a vehicle in dentifrice compositions. Applicants have found, surprisingly, that certain ethoxylated polyhydric alcohols having an effective amount of ethoxylation are useful in the preparation of aqueous dentifrice compositions.

Additionally, the ethoxylated polyhydric alcohols exhibit many advantages over the materials used in the prior art. The aqueous gel compositions made with surfactants in three polyoxyethylene / polyoxypropylene / polyoxyethylene blocks are thermally reversible, a property that formulators have taken advantage of to facilitate the processing of such gels. Additionally, the gels formulated with the surfactants in three blocks show an exceptional tolerance to electrolytes and are stable over wide ranges of pH and temperature. However, a common limitation with dentifrice gels formulated with copolymers of ethylene oxide and propylene oxide is that due to their thermally reversible gelation properties, the gels can be instantly liquefied in a pourable liquid as soon as the temperature falls below the sol-gel transition temperature. Such an event may possibly lead to fluid runoff from packaging. It has surprisingly been found that dentifrice compositions containing adequate amounts of ethoxylated polyhydric alcohols protect the tooth gel composition from the sudden loss of viscosity at lower temperatures. Another advantage of the ethoxylated polyhydric alcohols of the present invention is that they are good solvents for a variety of flavor oils.

SUMMARY OF THE INVENTION According to the present invention, there is provided an aqueous gel composition which comprises, a) an ethoxylated polyhydric alcohol which comprises a reaction product of an alcohol having between 3 and 6 hydroxyl groups with ethylene oxide; and b) a gelling agent selected from the group consisting of a surfactant in three polyoxyethylene / polyoxypropylene / polyoxyethylene blocks with a molecular weight between 4,000 and 16,000, and wherein the weight of the polyoxyethylene blocks ranges from 55% to 90% of the Surfactant weight in three blocks; a crosslinked polyacrylic thickener; cellulose derivatives; hydrated silicas; and mixtures thereof. In one embodiment, the invention is an aqueous gel composition comprising an ethoxylated polyhydric alcohol, a gelling agent and water. The ethoxylated polyhydric alcohol comprises the reaction product of an alcohol having between 3 and 6 hydroxyl groups with ethylene oxide, preferably in such a way that up to 5 mol equivalents of ethylene oxide are reacted per mole equivalent of hydroxyl group. The gelling agent is selected from the group consisting of surfactants in three polyoxyethylene / polyoxypropylene / polyoxyethylene blocks, crosslinked polyacrylic thickeners, cellulose derivatives, and hydrated silicas. When the gelling agent is the surfactants in three blocks, the ethoxylated polyhydric alcohol comprises the reaction product of the polyhydric alcohol and up to 5 mol equivalents of ethylene oxide per mole equivalent of hydroxyl group in the alcohol.

Detailed Description of a Preferred Embodiment The ethoxylated polyhydric alcohols of the present invention can be prepared by means well known in the art, by reacting a polyhydric alcohol with appropriate amounts of ethylene oxide in the presence of an alkaline catalyst. The resulting polyether can be optionally neutralized with neutralization acids well known in the state of the art. See, for example, Block & Graft Copolymerization, Volume 2, Chapter 1, edited by R.J.

Ceresa (Wiley, 1981), incorporated herein by reference. The polyhydric alcohols which are useful for producing the ethoxylated polyhydric alcohols of the present invention are generally those having between 3 to 6 hydroxyl groups. Examples of polyhydric alcohols include, but are not subject to glycerol, trimethylolpropane, 1,2,6-hexanetriol, ditrimethylolpropane, pentaerythritol, glucose and sorbitol. The ethoxylated polyhydric alcohol is therefore the reaction product of an alcohol having between 3 and 6 hydroxyl groups and an appropriate amount of ethylene oxide. As shown in Table 1, the ethoxylated polyhydric alcohols of the invention are good solvents for flavor oils. In Table 1, it can be seen that 0.2% solutions of the flavoring oils in the polyhydric alcohols (exemplified by a 12 mol glycerol ethoxylate) offer clear solutions while the glycerol solutions are opaque. TABLE 1 Solutions of flavor oils in ethoxylated polyhydric alcohol Table 2 presents a comparison of the physical properties of glycerin and three different ethoxylated polyhydric alcohols (represented by ethoxylated glycerol with levels of ethoxylation between 10 and 20). It is noted that while glycerol has a sweet taste, glycerol ethoxylates are essentially tasteless. That is, the ethoxylated polyhydric alcohols of the present invention do not have the sweet taste of glycerin. This may offer a benefit to formulators who do not prefer the sweet taste of glycerin. Formulations that use glycerin in such compositions usually have to rely on expensive flavoring agents to mask the sweet taste given by glycerin. Since the glycerol ethoxylates are basically unsatisfactory, the use of masking agents in dentifrice compositions can be minimized. Alternatively, the lack of candy can be compensated, if desired, by adding sweeteners to the compositions of the invention containing ethoxylated polyhydric alcohols.

TABLE 2 The ethoxylated polyhydric alcohols of the present invention find an application in water-based dentifrice compositions, in two ways, which will be described below. The first is as a component of an aqueous gel composition comprising a particular type of surfactant in three polyoxyethylene / polyoxypropylene / polyoxyethylene blocks. The ethoxylated polyhydric alcohols of the invention can be used to partially or completely replace the known compounds such as glycerol which have been used in such formulations up to now. For this application, the level of ethoxylation on the ethoxylated polyhydric alcohol can have a significant impact on the gelation properties. The second is as a humectant or vehicle in water-based dentifrice compositions comprising one or more known thickening agents such as cross-linked polyacrylic thickeners, cellulose derivatives, and hydrated silicas. The ethoxylated polyhydric alcohol can partially or completely replace commonly used humectants such as glycerol, sorbitol, propylene glycol, and polyethylene glycol. In this, the level of ethoxylation is not very critical for the gelling or thickening properties. However, if necessary, the ethoxylated polyhydric alcohols with relatively lower levels of ethoxylation may be used so that the desired wetting properties can be achieved. An aqueous gel composition is provided according to the present invention, which comprises a) an ethoxylated polyhydric alcohol which comprises a reaction product of an alcohol having between 3 and 6 hydroxyl groups with ethylene oxide; and b) a gelling agent selected from the group consisting of a surfactant in three polyoxyethylene / polyoxypropylene / polyoxyethylene blocks with a molecular weight between 4,000 and 16,000, and wherein the weight of the polyoxyethylene blocks ranges from 55% to 90% of the weight. surfactant weight in three blocks; crosslinked polyacrylic thickeners; cellulose derivatives; and hydrated silicas.

A preferred gelling agent is the surfactants in three polyoxyethylene / polyoxypropylene / polyoxyethylene blocks. The surfactant in three blocks is preferably present at a level between 16 and 40% by weight of the total composition, more preferably between 16 and 25% by weight. Such gelling agents in three blocks are well known in the state of the art. Preferred gelling agents contain an internal block of polyoxypropylene and two outer blocks of polyoxyethylene. The gelling agents in three blocks generally have a molecular weight of 4000 or more, and the molecular weight of the polyoxyethylene blocks ranges from 55 to 90% of the molecular weight of the surfactant in three blocks. The molecular weight of the surfactant in three blocks can be up to approximately 16,000. The gelling agents in three preferred blocks have a molecular weight greater than about 8,000, and a polyoxyethylene content between about 60 and 85%. Suitable gelling agents of this type are commercially available under the PLURONIC® surfactant line marketed by BASF Corporation, including in particular PLURONIC® F127, PLURONIC® F108, and PLURONIC® F98. On the other hand, the crosslinked polyacrylic thickeners can be used as the gelling agent. Examples of these crosslinked polyacrylic thickeners are the Carbopol products of B.F. Goodrich, such as those described in U.S. Pat. Nos. 2,798,053; 2,923,692; and 2,980,655; the disclosures are incorporated herein by reference. Crosslinked polyacrylic thickeners 10 Preferred also include water-dispersible copolymers of acrylic acid crosslinked with 0.75 to 1.5% sucrose and approximately polialílica neutralized with triethanolamine, NaOH, or other neutralizing agent, as disclosed in the U.S. No. 3,499,844, incorporated herein by reference. Cross-linked polyacrylic thickeners include Carbopol® 940, Carbopol® 934, and Ultrez® 10, products of B.F. Goodrich. Such thickeners are carboxylic acidic polymers insoluble colloidally water 20 acrylic acid crosslinked with 0.75 to 2% approximately crosslinking agent comprising sucrose or polyallyl pentaerythritol polialílica. They are present in the aqueous gel composition of the present invention at a level between about 0.1 and 10%, preferably between 0.5 and 5%, and more preferably between about 0.5 and 2%, based on the total weight of the composition. Another preferred type of gelling agent are cellulose derivatives. These include carboxymethylcellulose, hydroxyethylcellulose, hydroxyethylpropylcellulose, hydroxybutylmethylcellulose, hydroxypropylmethylcellulose, and sodium carboxymethylcellulose. They are present in the aqueous gel composition of the present invention at a level between about 0.1 and 3%, preferably between 0.5 and 2%, and more preferably about 1%. Commercially available examples of suitable cellulose derivatives include Aqualon® CMC-7MXF and CMC-9M8XF from Aqualon, a division of Hercules. The hydrated silicas useful in the invention are, generally, thickeners of precipitated silica. As such, they comprise a precipitate obtained when a solution of sodium silicate is acidified. A useful precipitated silica thickener is commercially available under the trademark Sident® 22S, a product of Degussa. In formulations of dentifrices containing water, hydrated silicas are advantageously used together with silica abrasives of low, medium, or high structure. The hydrated silicas can also be combined with other thickeners such as carboxymethylcellulose. The hydrated silicas are used in an effective amount, which usually ranges from 2% to 15% by weight, based on the total weight of the composition. The cellulose derivatives and the hydrated silicas useful in the gel compositions of the present invention are described in more detail in Chemistry & amp;; Technology of the Cosmetics & Toiletries Industry (Chemistry and Technology of the Cosmetics and Personal Care Products Industry), by D.F. Williams & W.H. Schmitt, pages 246-260, the disclosure of which is incorporated herein by reference. Aqueous Gel Compositions with Surfactants in Three Blocks In general, ethoxylated polyhydric alcohols can be used to produce aqueous gels of the present invention. When the gelling agent is the surfactant in three blocks of ethylene oxide / propylene oxide, it has been found that the level of ethoxylation of the polyhydric alcohol can critically impact the gel properties of the composition. In such a case, the ethoxylated polyhydric alcohols which are used are those which comprise the reaction product of an alcohol having between 3 and 6 hydroxyl groups, and an amount of ethylene oxide which, on average, up to 5 mol equivalents of ethylene are reacted per mole equivalent of hydroxyl in the polyhydric alcohol. For example, if the polyhydric alcohol is glycerol with three hydroxyl groups, the amount of ethylene oxide used can be up to 15 moles of ethylene oxide per mole of glycerol, so that an average of 5 moles of ethylene oxide react with each of the three mol equivalents of hydroxyl in the glycerol. Similarly, for sorbitol, a polyhydric alcohol with 6 hydroxyl groups, up to 30 moles of ethylene oxide are reacted with sorbitol so that, in this way, up to 5 mol equivalents of ethylene oxide are reacted per mole equivalent of hydroxyl in Sorbitol Therefore, when the gelling agent is the surfactant in three blocks, a preferred ethoxylated polyhydric alcohol is the ethoxylated glycerol which has on average up to about 15 units of ethylene oxide per glycerol molecule. Another preferred ethoxylated polyhydric alcohol is ethoxylated sorbitol which has on average up to about 30 units of ethylene oxide per molecule of sorbitol. To form the aqueous gels of the present invention when the gelling agent is a three-block surfactant, the ethoxylated polyhydric alcohol is generally used at a level between about 1 and 60%. Preferably it is used at a level between about 10 and 60% by weight of the total composition. More preferably between 15 and 50% is used and most preferably between 20 and 40% by weight. The aqueous gels of the invention may further comprise conventional humectants such as glycerol, sorbitol, propylene glycol, and liquid polyethylene glycols. When the ethoxylated polyhydric alcohols are present at less than 10%, it will generally be desirable to add one or more of the conventional humectants to the composition in such an amount that the total amount of the ethoxylated polyhydric alcohol plus the conventional humectant is at least 10% per approximately weight. Aqueous gel compositions can, advantageously, additionally comprise a peroxygen compound. Such peroxygen compounds are well known as ingredients of dentifrice compositions and include compounds that readily emit oxygen as the decomposition product. Such compounds include, but are not limited to, hydrogen peroxide and its alkali metal salts and alkaline earth salts, urea peroxide, percarbonate salts, perborates, perfosphates, persilicates, and peroxy organic acids such as peroxyacetic acid. These can be used at any effective level. Usually, levels between 0.1% and approximately 6% are useful, with the level between 1 and 4% preferred. The most preferred range ranges from about 1 to 3% by weight of the composition. The aqueous gel compositions may also advantageously comprise a flavor oil. Suitable flavor oils include, but are not limited to methyl salicylate, peppermint oil, peppermint oil, clove oil, menthol, anethole, eucalyptol, cassia, 1-methyl acetate, sage, eugenol, parsley oil, oxanone, alpha-iris, marjoram, lemon, orange, propenyl guaetol, cinnamon , vanillin, ethyl vanillin, heliotropin, 4-cis-heptenal, diacetyl, methyl-para-tert-butyl phenyl acetate, and mixtures thereof. A flavoring system is generally used in the compositions at levels between 0.001% to approximately 5%, by weight of the composition.

The aqueous gel compositions further comprise water in a suitable amount such that the levels of the ingredients are as stated above. Suitable gel compositions comprising the ethoxylated polyhydric alcohols and the surfactants in three blocks of the present invention have significant gel resistances at low temperatures as well as suitable gel resistances at higher temperatures. The simplest measure of gel strength is the viscosity of the gel composition, measured in centipoise using a Brookfield HBDV-III Cone / Plate Viscometer (viscometer) equipped with Spindle 51. All rheological measurements were recorded at the designated temperature using a shear rate of 38.4 reciprocal seconds. For purposes of the invention, the gel composition should have a viscosity of at least about 3000 centipoise over the temperature range of interest. Usually, below a certain temperature, which is characteristic of a gel composition system, the composition will exhibit a significantly lower viscosity than that which the composition has above that temperature. This temperature is called the sol-gel transition temperature. Depending on its application, it may be desirable to formulate a gel with a significant viscosity at low temperatures, such as at 10 ° C, or more preferably at 0 ° C, or even less. As seen in the Examples, it is possible with the compositions of the present invention to formulate gels having significant gel resistances at a temperature of -20 ° C or less. Similarly, there is a higher temperature, characteristic of the gel composition system, above which the composition no longer exists as a gel but which has less viscosity. Again, depending on its application, it may be desirable to formulate gel compositions where this transition temperature is at a relatively higher level. It can be seen from the Examples that it is possible to formulate gel compositions using the ethoxylated polyhydric alcohols and the surfactants in three blocks of the present invention having gel-like viscosities at 60 ° C or more. It is generally desirable that the lower sol-gel temperature is not above about 10 ° C and that the higher transition temperature is not less than about 40 ° C. It is more preferable that the higher temperature transition occurs at about 50 ° C or more, and it is even more preferred that the higher temperature transition be 60 ° C or more.

The dentifrice gels of the present invention can be prepared by adding the ethoxylated polyhydric alcohol and optional ingredients such as humectants, hydrogen peroxide, flavoring and water dyeing. After all the ingredients are dissolved, the surfactant gelling agent in three blocks is added and the mixture is slowly stirred to disperse the gelling agent. The composition is then stored at -20 ° C, and the mixture is agitated periodically to facilitate hydration of the gelling agent. In a plant, this is achieved by mixing and hydrating in a reactor equipped with cooling means to maintain the temperature below the sol-gel transition temperature of the gel composition. After the above mixing step, the composition may contain significant amounts of trapped air. When desired, an aeration is performed by known techniques. For example, the mixture can be maintained in the reactor below the sol-gel transition point so that the viscosity would be below about 3000 centipoise. A vacuum can then be applied to the mixture for a sufficient time to remove trapped air bubbles. The gel composition can also be centrifuged to remove any trapped air. A non-limiting example of a typical non-abrasive dentifrice-based tooth gel composition comprising a polymer in three polyoxyethylene / polyoxypropylene / polyoxyethylene blocks as the gelling agent and an ethoxylated glycerol adduct is shown below. All percentages are by weight of the total composition. Trifloque polymer E0 / P0 / E0 20% (Pluronic® F-127) Ethoxylated adduct of glycerol 20% (10 moles of EO) Hydrogen peroxide 1.5% Flavoring 0.2% Detergent 1.5% Purified Water Difference up to 100% Additional agents such as buffering agents or neutralizing agents that are typically used to adjust the pH or improve the stability of the peroxide in the composition may also be added in minor amo to the above aqueous dentifrice compositions. Optionally, the compositions may have minor amo of chelating agents such as ethylenediamine tetraacetic acid or its variants or mixtures thereof, to help prevent premature decomposition of the peroxygen compound in the composition. Likewise, with certain gel compositions, it may be desirable to incorporate common humectants such as glycerol or sorbitol to further expand the stability of the gel at temperatures above 60 ° C. Therapeutic benefits of using such an aqueous gel composition as a dentifrice can be substantially enhanced by using a combination of the above dentifrice gels in conjunction with a highly abrasive dentifrice composition described below: Toothpaste 22-55% Fluoride salts 0.1-0.9% Abrasive 20-60% (sodium bicarbonate, dicalcium phosphate) Thickening agent 0-5% Flavoring 0.1-0.9% Foaming agent 0.5-2% Mise additives, Sweeteners, 0.3-3.5% Fluorizing agent, Foam enhancers Water at discretion Compositions of aqueous gel with other gelling agents When the gelling agent is selected from the group consisting of crosslinked polyacrylic thickeners, cellulose derivatives, and hydrated silicas, it has been found that the level of ethoxylation of the ethoxylated polyhydric alcohol is not as critical as it is if the gelling agent was the surfactant in three blocks. Accordingly, the ethoxylated polyhydric alcohol can be the reaction product of an alcohol having 3 to 6 hydroxyl groups, with ethylene oxide up to a molecular weight of about 10,000 or more. Preferably the molecular weight will be less than about 4,000. Preferred ethoxylated polyhydric alcohols are those with up to about 100 moles of ethylene oxide added per mole of the polyhydric alcohol; more preferred is less than 50-70 moles of ethylene oxide per mole of the polyhydric alcohol. In prolonged exposures, dentifrice compositions containing water tend to lose moisture and gradually harden, eventually losing their tooth-like consistency. To prevent this, humectants, such as glycerin or low molecular weight polyethylene glycols, have usually been used to restore the moisture balance in the tooth composition. It has been found that polyhydric alcohols with an adequate level of ethoxylation are suitable for use as humectants in dentifrice compositions and can replace, advantageously in whole or in part, humectants of the prior art. Therefore, when relatively higher wetting properties are required, the ethoxylated polyhydric alcohols with a relatively lower level of ethoxylation are more suitable for use. As an example, it has been found that glycerol ethoxylates with an ethoxylation level below about 15 usually have adequate wettability. More preferably, for a greater wetting, an ethoxylation level less than or equal to about 10 is preferred. The level of ethoxylation here refers to the total number of units of ethylene oxide which is reacted with the initial polyhydric alcohol. To further illustrate, if the level of ethoxylation of glycerol is said to be about 20, it means that one refers to an ethoxylated glycerol having approximately 20 ethylene oxide units per glycerol molecule.

To form the aqueous gels of the present invention wherein the gelling agent is selected from the group consisting of ethoxylated polyacrylic thickeners, cellulose derivatives, and hydrated silicas, the ethoxylated polyhydric alcohol is generally used at a level between 1 and 60% approximately. Preferably it is used at a level between 10 and 60% by weight of the total composition approximately. The aqueous gels of the invention may additionally comprise conventional humectants such as glycerol, sorbitol, propylene glycol and liquid polyethylene glycols. When the ethoxylated polyhydric alcohols are present in less than 10%, it will generally be desirable to add one or more of the conventional humectants to the composition in such an amount that the total amount of the ethoxylated polyhydric alcohol plus the conventional humectant is at least 10% per approximately weight. It was noted above that the ethoxylated polyhydric alcohols of the invention are better solvents for various flavor oils than conventional humectants such as glycerol. Therefore, the use of ethoxylated polyhydric alcohols in dentifrice compositions improves the dispersion and solubilization of flavor oils in such compositions. Compositions comprising ethoxylated polyhydric alcohols and a gelling agent selected from crosslinked polyacrylic thickeners, cellulose derivatives, and hydrated silicas, are typically formulated with conventional additives to produce aqueous dentifrice compositions. A typical toothpaste would have, in addition to the ethoxylated polyhydric alcohol and the gelling agent, other additives such as: Fluoride salts 0.1-0.9% Abrasive 20-60% Baking powder 0-10% Thickening agent 0-5% Flavor oil 0.1- 5% Foam agent 0.5-2% Mise additives, sweeteners, foam enhancers 0.3-3.5% Water at discretion The flavor may be one or a mixture of the flavoring oils described above. Fluoride salts are those that are capable of delivering free fluoride ions. Preferred salts, which are sources of fluoride ions, include sodium fluoride, stannous fluoride, indium fluoride, potassium fluoride, and sodium monofluorophosphate. Sodium fluoride and stannous fluoride are preferred. Such sources of fluoride ions and others are disclosed in U.S. Pat. No. 2,946,725 and U.S. Pat. No. 3,678,154, the disclosures of which are incorporated herein by reference. The fluoride ion source should be capable of delivering between 50 ppm and 3500 ppm approximately, preferably between 500 ppm and 3000 ppm approximately, free fluoride ions. The abrasive polishing material contemplated for use in the compositions of the present invention can be of any material that does not excessively wear dentin. Typical abrasive polishing materials include carbonates. They also include silicas, including gels and precipitates, aluminas, phosphates including the orthophosphates, polymetha- phosphate and insoluble pyrophosphates, and mixtures thereof. The abrasive may be precipitated silica or silica gels, such as the silica xerogels described in U.S. Pat. Nos. 3,538,230 and 3,862,307, the disclosures of which are incorporated herein by reference.

Suitable thickeners include Irish moss, tragacanth gum, starch, hydroxyethylpropylcellulose, hydroxybutylmethylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, sodium carboxymethylcellulose, poly (methylvinyl ether / maleic anhydride) available as Gantrez® AN139 at the GAF Corporation and carboxylvinyl polymer available as Carbopol® 934 or Carbopol® 941 of the BF Goodrich. Foaming agents useful in the dentifrice compositions of the present invention include surfactants selected from anionic, cationic, nonionic, and amphoteric surfactants. Particularly preferred are anionic surfactants such as sodium lauryl sulfate, lauroyl sodium sarcosinate, sodium lauryl ether sulfates, alkyl and sodium glyceryl ether sulfonate, and alkylbenzene sulfonate. The solid block copolymers of polyoxyethylene and polyoxypropylene can be used to provide an additional enhancement in the performance of foam production of the tooth composition. Additionally, small amounts of cationic surfactants having a quaternary nitrogen can also be used. Examples of such surfactants are betaines, such as, for example, cacoamidopropylbetaine. Such foam agents are usually present in a range between 0.5 and 2% by weight approximately of the total composition. The sweetening agents can also be added to the dentifrice compositions of the present invention. These include saccharin, dextrose, sucrose, lactose, maltose, levulose, aspartame, sodium cyclamate D-tryptophan, dihydrochalcones, acesulfame, and mixtures thereof. Various coloring agents can also be incorporated in the present invention. Sweetening and coloring agents are generally used in dentifrice compositions at levels between about 0.005% and 5% by weight of the composition.

Examples 1-4 Example 1 offers a typical formulation and Example 2 gives a specific formula for an aqueous gel dentifrice composition comprising an ethoxylated polyhydric alcohol of the invention and a gelling agent in three EO / PO / EO blocks. Example 3 offers a typical formulation and Example 4 gives a specific formula for an aqueous gel dentifrice comprising an ethoxylated polyhydric alcohol of the invention and a cross-linked polyacrylic gelling agent.

Examples 1-4 Examples 5-13 Examples 6-10 illustrate aqueous gel compositions wherein the gelling agent is the surfactant in three blocks (Pluronic® F127 surfactant). In all the examples, the water is present at a level such that the total weight of the composition is 100. The viscosity values are given in cetipoises, measured by a Brookfield Spindle 51 viscometer at 38.4 S_1. The critical nature of the ethoxylation level is seen when comparing Examples 8 and 9. In Example 9, a glycerol ethoxylate of 12 moles is used to prepare a useful gel composition in a temperature range of 10-60 ° C. However, in Example 8, it is observed that an ethoxylated glycerol having 20 moles of ethylene oxide does not offer a gel composition with sufficient viscosity at the same temperature to be useful as an aqueous gel dentifrice.

Example 11 shows that sorbitol (used herein as the commercially available mixture of 70% sorbitol / 30% water) is not effective in forming aqueous gels with the surfactant in three non-ionic blocks. However, Example 7 shows that when the sorbitol is ethoxylated at a level of 5 moles of ethylene oxide per mole of sorbitol, a gel results having very useful viscosity properties in the temperature range between 10-60 ° C. Example 12 shows that sorbitol + 40 moles of ethylene oxide, outside the range of the invention, does not produce a gel in combination with the non-ionic three-block surfactant. Example 13 shows a gel composition of the present invention having a sufficient viscosity (ie, greater than 3000 cps) in the temperature range of -20 ° C to 60 ° C. As noted, the composition of Example 13 additionally contained 1.5% by weight of hydrogen peroxide.

H1 or O Examples 5-13 not measured, since at 20 ° C (room temperature) there was no gel, and no gel was expected at higher temperatures b not measured, since obviously < 1426 is at lower temps, c the composition additionally contained 1.5% by weight of hydrogen peroxide.

Claims (20)

1. CLAIMS: 1. A composition of the aqueous gel comprising: a) an ethoxylated polyhydric alcohol, which comprises a reaction product of an alcohol having ? between 3 and 6 hydroxyl groups and an amount of ethylene oxide, in such a way that up to 5 mol equivalents of ethylene oxide are reacted per mole equivalent of hydroxyl; b) a three-polyoxyethylene / polyoxypropylene / polyoxyethylene 13-block surfactant with a molecular weight between 4,000 to 16,000, and wherein the weight of the polyoxyethylene blocks ranges from 55% to 90% by weight of the surfactant in three blocks; and c) water
2. 2. A gel composition according to claim 1, wherein said ethoxylated polyhydric alcohol comprises an ethoxylated glycerol which on average has up to 15 units of ethylene oxide per glycerol molecule.
3. 3. A gel composition according to claim 1, in Wherein said ethoxylated polyhydric alcohol comprises an ethoxylated sorbitol which on average has up to 30 units of ethylene oxide per molecule of sorbitol. 33 25
4. 4. A gel composition according to claim 1, further comprising a peroxygen compound.
5. 5. A gel composition according to claim 1, further comprising a flavor oil.
6. 6. A gel composition according to claim 1, wherein the ethoxylated polyhydric alcohol comprises an ethoxylated glycerol which on average has up to 12 units of ethylene oxide per glycerol molecule.
7. 7. A gel composition according to claim 1, wherein the ethoxylated polyhydric alcohol comprises an ethoxylated glycerol which on average has about 10 units of ethylene oxide per glycerol molecule, and the surfactant in three blocks has a molecular weight of about 4000. up to 16,000, and a percentage by polyoxyethylene content of about 55 to 90%.
8. 8. A gel composition according to claim 1, which comprises between 1 to 60% by weight of said ethoxylated polyhydric alcohol and between 16% and 40% by weight of said surfactant in three blocks, wherein the percentages are based on weight total gel composition.
9. 9. A gel composition according to claim 1, further comprising one or more humectants selected from glycerol, sorbitol, propylene glycol, and polyethylene glycol.
10. 10. A gel composition for use in aqueous dentifrice compositions, which comprises: a) an ethoxylated polyhydric alcohol, which comprises a reaction product of an alcohol having between 3 and 6 hydroxyl groups and ethylene oxide; and b) a gelling agent selected from the group consisting of surfactants in three polyoxyethylene / polyoxypropylene / polyoxyethylene blocks with a molecular weight between 4,000 to 16,000, and wherein the weight of the polyoxyethylene blocks ranges from 55% to 90% of the weight of the surfactant in three blocks; crosslinked polyacrylic thickeners; cellulose derivatives; hydrated silicas; and mixtures thereof.
11. 11. A gel composition according to claim 10, wherein said ethoxylated polyhydric alcohol comprises an ethoxylated glycerol having up to 100 units of ethylene oxide per glycerol molecule approximately.
12. 12. A gel composition according to claim 10, wherein said ethoxylated glycerol comprises glycerol with less than or about 15 ethylene oxide units per glycerol molecule.
13. 13. A gel composition according to claim 12, wherein said ethoxylated glycerol comprises glycerol with less than or about 10 ethylene oxide units per glycerol molecule.
14. 14. A gel composition according to claim 10, comprising between about 10% and about 60% by weight of said ethoxylated polyhydric alcohol, and wherein said gelling agent comprises between 0.1% to 10% of a crosslinked polyacrylic thickener.
15. 15. A gel composition according to claim 14, further comprising one or more humectants selected from glycerol, sorbitol, propylene glycol, and polyethylene glycol.
16. 16. A gel composition according to claim 10, comprising between about 10% and about 60% by weight of said ethoxylated polyhydric alcohol, and wherein said gelling agent comprises between 0.1% and 3% of a cellulose derivative.
17. 17. A gel composition according to claim 16, further comprising one or more humectants selected from glycerol, sorbitol, propylene glycol, and polyethylene glycol.
18. 18. A gel composition according to claim 10, comprising between about 10% and about 60% by weight of said ethoxylated polyhydric alcohol, and wherein said gelling agent comprises between 2% and 15% of a hydrated silica.
19. 19. A gel composition according to claim 18, further comprising one or more humectants selected from glycerol, sorbitol, propylene glycol, and polyethylene glycol.
20. 20. A gel composition according to claim 10, further comprising a flavor oil.