MXPA96001758A - Abrasive silicate decision of reduced fibrosity and better taste - Google Patents

Abstract

The present invention relates to a flavored silica abrasive dentifrice that delivers higher levels and intensity of flavor and exhibits less fibrousness, the dentifrice has incorporated therein a cellulose gel composed of a coprocessed mixture of microcrystalline cellulose and a cellulose gum such as carboxymethyl cellulose

Description

ABRASIVE DENTAL ABBREVIABLE DB SILICB REDUCED PIBROSIDAD AND ENHANCED FLAVOR 1. Field of the Invention This invention relates to silica abrasive dentifrice compositions, especially toothpastes and dental gels of silica abrasives having improved physical properties and taste. 2. Previous Art A thickener is commonly employed in toothpaste compositions to prevent separation of the ingredients in storage, promote dispersion and retention in use as on a toothbrush. Such thickeners are generally hydrophilic colloids which are dispersed in the aqueous medium. The most widely used thickeners are cellulose gums because they are cheap and their quality can be controlled closely. Carboxymethyl cellulose is a rubber thickener widely used in silica abrasive dentifrices but such toothpastes frequently exhibit excessive "fibrousness" when extruded from a tube. It has therefore been found that the use of cellulose gums in the preparation of toothpastes or silica abrasive gels results in products forming a fibrous glue which is attached to the end segment of the toothpaste extruded from a tube. . If an excessive amount of glue is formed, the dentifrice is characterized as having too much fibrosity. Consumers see fibrosity as aesthetically unpleasant. Consumers have expected an acute break toothpaste as provided by conventional high abrasive dentifrices. In addition, the glue can unintentionally get into the threads of the lid, neck and other parts of the tube creating a dirty appearance not attractive to the product.

In addition to the problem of fibrosity, silica abrasive dentifrices have been found, with respect to a given amount of flavoring, to exhibit distorted flavor profiles and poor quality compared to other abrasive dentifrices such as, for example, phosphate abrasive toothpastes. dicalcio. The taste distortion is believed to be caused by the absorption of some of the flavor components on the silica particle surface when the flavor profile is distorted.

Summary of the Invention The present invention relates to a silica abrasive dentifrice which exhibits reduced fibrosity and improved flavor quality when the dentifrice is composed of a silica dental abrasive, a humectant, water, flavor and cellulose gel formed by a co-processed mixture. of microcrystalline cellulose and cellulose gum.

Description of the Preferred Modalities The dentifrice compositions of the present invention contain from about 15 to about 30% by weight and preferably from about 18 to about 24% by weight of a silica abrasive. The silica abrasive used here generally has an average particle size ranging from about 0.1 to 30 microns, preferably from 5 to about 15 microns. The preferred silica abrasive materials in the practice of the present invention are those marketed by J. M. Huber Corporation under the name "Zeodent" particularly the silica bearing the designation Zeodent 115.

The cellulose gel used as a thickener in the practice of the present invention is a cellulose gel formed from a dried, spray-dried or volume-dried mixture, coprocessed with a microcrystalline cellulose and a cellulose gum such as a carboxymethyl cellulose, xanthan gum or sodium alginate.

An example of such cellulose gels are those sold by FMC Corporation under the name Avicel. These cellulose gels, useful in the practice of the present invention, generally contain about 80 to about 90% by weight of microcrystalline cellulose and about 10 to about 20% by weight of cellulose gum. The particle size range of the gel is submicron, that is, from less than 0.2 microns to about 100 microns, and preferably from about 0.2 to about 20 microns. A preferred cellulose gel for use in the practice of the present invention is Avicel RC-591-F which is a spray-dried cellulose gel having the following composition and properties: % 88% Colloidal Microcrystalline Cellulose (0.2 microns) 70% Carboxymethyl Cellulose 12 Initial Viscosity * 39-175 to 1.2% Viscosity Established ** 1250 cps to 1.2% * Initial Viscosity: 120 seconds using a Brookfield RVT Viscometer # 1 spindle at 20 rpm.

** Viscosity Established: 24 hours using a Brookfield RVT Viscometer # 3 spindle at 20 rpm.

The cellulose gel is present in the dentifrice compositions of the present invention at a concentration of from about 0.1 to about 1.0% by weight and preferably from about 0.3 to about 0.5% by weight.

The vehicle used in the dentifrice compositions of this invention generally comprises about 6 to about 60% by weight of water and about 20 to about 70% by weight of a humectant. The humectant content preferably ranges from about 40 to about 60% on a pure basis and the water content preferably ranges from about 10 to about 40%, and more preferably from about 12 to about 20% by weight.

Suitable humectants for use in these dentifrice compositions include, for example, sorbitol (usually in the form of a 70% aqueous solution), glycerin, propylene glycol, xylitol, and / or polyethylene glycol (for example polyethylene glycol 400-600), especially mixtures of glycerin, sorbitol and polyethylene glycol.

In the tooth preparations of the present invention, a fluoride ion stripping compound in an amount which releases about 25 to about 5,000 ppm of fluoride ion and preferably about 800 to 1,500 ppm of fluoride ions is incorporated into the toothpaste. . Fluoride compounds useful in the practice of the present invention include the alkali metal fluorides such as stannous fluoride and sodium fluoride and sodium monofluorophosphate.

It will be understood that rubber thickeners may be included in the tooth compositions of the present invention. Examples of such rubber thickeners include xanthan gum, hydroxyethyl cellulose and water soluble salts of cellulose ethers such as carboxymethyl cellulose and hydroxyethyl cellulose. Natural gums, such as carrageenan (Irish musto, Viscarina), karaya gum, gum arabic, and tragacanth gum can also be used. Also useful are water-soluble hydrophilic colloidal carboxyvinyl polymers such as those available from B.F. Goodrich Company under the trademark Carbopol 940P, 971P. The rubber thickeners are included in the dentifrice compositions of the present invention at a concentration of from about 0.25 to about 2.5% by weight and preferably from about 1.0 to about 1.5% by weight.

Surfactants can be included in the dentifrice compositions of the present invention at a concentration of about 0.8 to 2.5% by weight and preferably from about 1.0 to about 1.5% by weight. Examples of suitable surfactants include the water-soluble salts of monoglyceride monosulfates of higher fatty acid, such as the sodium salt of the monosulfated monoglyceride of hydrogenated coconut oil fatty acids, the higher alkyl sulfates such as sodium lauryl sulfate, the alkylaryl sulfonates, such as the sodium dodecyl benzene sulfonate, the higher alkyl sulfoacetates such as sodium lauryl sulphoacetates, the higher fatty acid esters of 1,2-dihydroxy propane sulfonate, and the substantially saturated higher aliphatic acyl amides of acid compounds lower aliphatic carboxylic amino, such as those having from 12 to 16 carbon atoms in the fatty acid, alkyl or acyl radicals, and the like.

Examples of suitable flavor constituents useful in the practice of the present invention are the flavoring oils, for example, peppermint oil, peppermint, pyrol, sassafras, clove, sage, eucalyptus, marjoram, cinnamon, lemon, and orange and methyl salicylate. The flavor oil is incorporated into the dentifrice composition of the present invention at a concentration of about 0.1 to 2.0% by weight and preferably of about 0.5 to about 1.5% by weight.

The sweetening agents can be used in the preparation of the dentifrice compositions of the present invention. Suitable sweetening agents include sucrose, lactose, maltose, sorbitol, xylitol, sodium cyclamate, perillartin, aspartyl phenyl alanine, methyl ester, saccharin and the like. The sweetening agent comprises from about 0.1% by weight to about 2% by weight of the dentifrice composition.

Pyrophosphate salts having an anti-tartar efficacy such as tetraalkaline or dialkyl metal pyrophosphate salts such as Na4P207, K4P207, Na2K2P207, Na2H2P207 and K2H2P207, long chain polyphosphates such as sodium hexametaphosphate and cyclic phosphates such as sodium trimetaphosphate are they incorporate in the dentifrice compositions of the present invention preferably at a concentration of about 0.5 to about 8.0% by weight and preferably from about 1.5 to about 3% by weight.

Antibacterial agents can also be included in the oral compositions of the present invention. Especially useful are non-cationic antibacterial agents which are based on phenolic and bisphenolic compounds, halogenated diphenyl ether, benzoate esters and carbanilides. Examples of such compounds are 4-chlorophenol, 2,2'-trichloro-2-hydroxy-diphenyl ether (Triclosan), esters of p-hydroxybenzoic acid, especially methyl, ethyl, propyl, butyl and benzyl esters, 3,4 , 4'-trichlorocarbanilide and 3,3'-trichlorocarbanilide. Triclosan in amounts ranging from 0.03% to 1% is preferred for use in the compositions of the present invention. Nonionic antimicrobial agents such as sesquiterpene alcohols such as merolidol and bisabolol are also useful herein in the present invention.

Teeth whitening agents can also be included in the oral compositions of the present invention. Oxidizing agents such as calcium peroxide, hydrogen peroxide, urea peroxide, peracetic acid, sodium percarbonate are especially useful. The amount of active oxygen in such oral compositions can vary from 0.1% to 5% by weight and preferably from about 0.5% to about 2% by weight.

The dentifrice composition of the present invention can be prepared by mixing the ingredients wherein a first premix was prepared by dispersing a cellulose gel with a portion of the humectant and water. A second premix is prepared by mixing water with a fluoride compound such as sodium fluoride or sodium monofluorophosphate, and a sweetener such as saccharin are then added and mixed. A premix of gel is prepared by dispersing a rubber thickener and an anticalculus salt in a second portion of the humectant. After dispersing the ingredients of the gel premix, the gel premix is combined with the second premix ingredients, to which is added a silica polishing agent such as zeodent 115, a surfactant, flavor and a pigment. . Other optional ingredients can be added to the combined premixes. The combined second and gel premixes and the first premix are sequentially added to a suitable high speed mixer. These ingredients are then mixed under vacuum for about 15-30 minutes. The resulting paste or gel is then piped.

The following examples are further illustrative of the present invention, but it is understood that the invention is not limited thereto. All amounts and proportions mentioned here and in the attached clauses are by weight unless otherwise indicated.

Example 1 A toothpaste composition of the present invention containing cellulose gel having a composition designated "A" was prepared in accordance with the practice of the present invention. A second comparative toothpaste composition designated "B" was prepared in which the cellulose gel was not included in the composition. The ingredients of compositions a and B are listed below: Composition% by Weight Ingredients A B Sorbitol 46.307 34.557 Glycerin 10,000 22.00 Polyethylene glycol 3.00 3.00 Carboxymethyl cellulose 0.45 0.50 Avicel RC591-F 0.30 Tetrasodium pyrophosphate 0.50 0.50 Ti02 0.30 0.30 Saccharin 0.25 0.25 NaF 0.243 0.243 Deionized water 12.00 12.00 Zeodent 115 22.00 22.00 Sylox 15 * 2.50 2.50 Flavor ** 0.95 0.95 Sulfate sodium lauryl 1.20 1.20 * Silica thickener available from W.R. Grace ** Blend of peppermint and peppermint.

Composition A was prepared by mixing 15% sorbitol together with Avicel RC591-F until dispersed followed by the addition of 3% by weight of water to prepare a first premix. A second premix was prepared by mixing the sodium fluoride and the saccharin with water until they dissolved. A gel premix was prepared by mixing the ingredients of glycerin, carboxymethyl cellulose, tetrasodium pyrophosphate and Ti02 with the remaining sorbitol. The second premix and the gel premix were then combined and transferred to the DOPP mixer followed by the first premix. The Zeodent 115, NaF, lauryl sodium flavor and sulfate were added to the mixture, and the ingredients mixed under vacuum for about 15 minutes to obtain a homogeneous paste.

Composition B was prepared in a similar manner except that the Avicel RC591F was not used in its preparation.

To estimate the flavor release properties of compositions A and B, the test specimens were prepared which were composed of a mixture of equal parts of undiluted toothpaste composition, the toothpaste composition diluted 1: 1 with water and composition of toothpaste diluted 3: 1 with water (the proportions are proportions by weight).

The intensity of the savor of the toothpaste compositions A and B were determined using gas chromatography. In this determination of flavor intensity, 5 milliliters (ml) of the toothpaste specimen were placed in a 22 ml beaker and equilibrated at 60 ° C for one hour. Levigating vapors within the headspace of the container were collected by syringe and injected into the gas chromatograph inlet. The various components of the flavor oils retained on the gas chromatograph column levigrated out of the column at different retention times. Steam retention times levigated on the gas chromatography column are used to identify the different flavor components. The intensity of the flavor component was graded by the area under the peak associated with the particular flavor component. Peak intensity is a measure of the amount of flavor released from the toothpaste; the higher the area under the peak, the greater the intensity of flavor. The intensity results are recorded in Table I given below.

For the purposes of a further comparison, a commercial silica abrasive gel dentifrice designated composition C was also evaluated for flavor intensity. These comparative results are also recorded in Table I given below.

Table I Total Destroyed Flavor of Mixed Dentifrices Composition Area Low Peak X 106 Time - Weeks Initial 6 16 A 27. 2 26. 2 25. 9 B 25. 8 24. 9 24. 0 C 26. 2 26. 0 23. The results recorded in Table I show that Composition A which contains Avicel gives a greater flavor release than composition B in which the Avicel is absent, as well as composition C, the commercial silica abrasive gel dentifrice.

Example II To evaluate the fibrosity of compositions A and B, the toothpaste samples were placed in sandwich form between two parallel stainless steel plates and an electric current of 0.1-100 milliamperes was passed between the plates. The dental plaque sample served as a conducting medium for the stream. The plates were then slowly separated and a string of dough formed between the separating plates. The current stopped flowing when the toothpaste cord broke. The distance between the plates to the breaking point of the rope was measured, and this distance was a measure of the fibrousness of the toothpaste sample. The fibrosity was then quantified numerically by means of a "Rope Value" determined from a graph of the current as a function of time. The lower the rope value the less fibrous and dirty and the more acceptable the product was to the consumer.

The Rope Value of Compositions A and B as well as composition C a commercial silica abrasive gel are recorded in Table II below: Table II String Value Composition A 5.1 B 10.0 C 14.1 The Rope Values recorded in Table II indicate that the dentifrice composition of the present invention, composition A, has a Rope Value which is substantially less than the comparative dentifrice composition B in which a cellulose gel ingredient is absent. as well as a commercial silica abrasive toothpaste (Composition O.

Claims (20)

R E I V I ND I CA C I ONE S

1. A dentifrice composition which exhibits a reduced fibrosity and an improved flavor intensity, the dentifrice being composed of an abrasive silica, water, humectant, flavor, thickener and a cellulose gel composed of a co-processed mixture of a microcrystalline cellulose and a rubber of cellulose.

2. The dentifrice composition, as claimed in clause 1, characterized in that the cellulose gel contains from about 80 to about 90% by weight of microcrystalline cellulose and from about 10 to about 20% by weight of the cellulose gum .

3. The dentifrice composition, as claimed in clause 1, characterized in that the cellulose gum is carboxymethyl cellulose.

4. The dentifrice composition, as claimed in clause 1, characterized in that the cellulose gel is present in the dentifrice at a concentration of about 0.1 to about 1.0% by weight.

5. The dentifrice composition, as claimed in clause 1, characterized in that the flavor is present in the dentifrice at a concentration of about 0.1 to about 2% by weight.

6. The dentifrice composition, as claimed in clause 1, characterized in that the silica abrasive is present in the dentifrice at a concentration of about 15 to about 30% by weight.

7. The dentifrice composition, as claimed in clause 1, characterized in that water is present in the composition at a concentration of about 6 to about 60% by weight.

8. The dentifrice composition, as claimed in clause 1, characterized in that the humectant is present in the composition at a concentration of from about 20 to about 70% by weight.

9. The dentifrice composition, as claimed in clause 1, characterized in that the thickener is present in the composition at a concentration of about 0.10 to about 2.5% by weight.

10. The dentifrice composition, as claimed in clause 9, characterized in that the thickener is carboxymethyl cellulose.

11. A method for improving the flavor intensity and reducing the fibrosity of silica abrasive dentifrices comprising incorporating into the dentifrice containing a silica abrasive, water, humectant, flavor and thickener, a cellulose gel comprising a co-processed cellulose blend microcrystalline and a cellulose gum.

12. The method, as claimed in clause 11, characterized in that the cellulose gel contains from about 80 to about 90% by weight of the microcrystalline cellulose and from about 10 to about 20% by weight of the cellulose gum .

13. The method, as claimed in clause 11, characterized in that the cellulose gum is carboxymethyl cellulose.

14. The method, as claimed in clause 11, characterized in that the cellulose gel is present in the dentifrice at a concentration of about 0.1 to about 1.0% by weight.

15. The method, as claimed in clause 11, characterized in that the flavor is present in the dentifrice at a concentration of about 0.1 to about 2% by weight.

16. The method, as claimed in clause 11, characterized in that the silica abrasive is present in the dentifrice at a concentration of about 15 to about 30% by weight.

17. The method, as claimed in clause 11, characterized in that the water is present in the composition at a concentration of about 6 to about 60% by weight.

18. The method, as claimed in clause 11, characterized in that the humectant is present in the composition at a concentration of from about 20 to about 70% by weight.

19. The method, as claimed in clause 11, characterized in that the thickener is present in the composition at a concentration of about 0.10 to about 2.5% by weight.

20. The method, as claimed in clause 19, characterized in that the thickener is carboxymethyl cellulose. SUMMARIZES A flavored silica abrasive dentifrice is disclosed which delivers superior levels and intensity of taste and exhibits less fibrousness, the dentifrice has therein incorporated a cellulose gel composed of a co-processed microcrystalline cellulose blend and a cellulose gum such as carboxymethyl cellulose.