NL8204516A - STABLE TOOTHIC WITH AN ACID SILICONE POLISH. - Google Patents

Description

* * VO 3902 -1-

Stable dentifrice with an acidic silicon-containing polish.

The invention relates to a stable dentifrice and in particular to a dentifrice which can be used in an unlined aluminum tube.

According to the present invention, a stable dentifrice 5 consists of an aqueous, dentally acceptable oral carrier, with at least 27.5 wt% and usually 30-60 wt%, preferably 40-55 wt% *, e.g. about 45 wt% % of the dentifrice consists of water and in the said oral carrier 10 - 40% by weight, preferably 10 - 30% by weight and in particular 15 - 25% by weight, based on the dentifrice, of an acid siliceous polishing agent, for example, an alkali metal aluminum silicate, is dispersed, characterized in that it has a stirred slurry pH (as defined herein) from 5 to less than 6.5, preferably 5 - 6.4 , for example 5.1, 5.2, 5.3 or 5.4 to 6.3, 6.2, 6.1 or 6.0, in particular 5.5 - 6.0 and 15 more in particular 5, 7 - 5.9, as well as a stabilizing amount of a monofluorophosphate ion, the dentifrice having a stirred slurry pH of 5.5 - 8, preferably 6.5 - 7.5 and especially r 6.7 - 7.3, optionally containing a non-toxic amount of at least 0.2% by weight of the dentifrice of chloroform and, if desired, at least when chloroform is present, at least 0.05-5% by weight, based on the dentifrice of a stabilizing anionic phosphate ester mixture, said mixture consisting of a monoester of the formula 1 and a diester of the formula 2, wherein R is an alkyl group of 10-20 carbon atoms; n represents a number from 1 to 6; and M represents hydrogen, alkali metal or ammonium. The stabilizing anionic phosphate ester mixture reduces or prevents corrosion in the presence of chloroform and stabilizes the dentifrice.

An advantage of this invention is that it provides a stable dentifrice with a siliceous polishing agent.

The stability to which the present invention relates.

is the substantial absence of gas-evolving reactions between the components of the dentifrice and the aluminum surface of an unlined aluminum tube, as evidenced by the absence of visually perceptible swelling of the closed dentifrice tube containing the dentifrice 35 when said tube 168 kept at 43 ° C for days.

The invention also extends to an unlined aluminum tube which has just been filled with a stable dentifrice of the present invention.

. The stabilizing monofluorophosphate ion can be provided by 8204516

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Any suitable compound thereof, but a particularly suitable compound is sodium monofluorophosphate.

It can be used in any amount which has the necessary, defined stabilizing effect on the particular embodiment of the dentifrice according to the invention, but amounts. providing at least 0.01% monofluorophosphate ion means careful use and at least 0.05% or at least 0.075 or 0.09% should be used to achieve greater certainty. Such amounts of the monofluorophosphate ion will be supplied by sodium 10-monofluorophosphate, when present in amounts of 0.076? 0.38? 0.57 or 0.68. Use of 0.7-0.8% sodium monofluorophosphate has been found to be particularly effective, and a preferred amount thereof is therefore at least 0.7%. Larger quantities are not excluded, but an upper limit of 7.6% will usually not be exceeded.

The polishing material used in the present invention is an acidic siliceous material which may contain a small amount, for example up to about 10% or slightly more, of aluminum oxide bound in the silica grid. Furthermore, it can be characterized in that it is synthetic and amorphous and it has a refractive index of between about 1.4 and 1.5.

If desired, other polishing agents which as individual components do not contribute significantly to instability or corrosivity with a non-lined aluminum surface may also be present.

Such additional polishing agents include aicalcium phosphate dihydrate and anhydrous dicalcium phosphate, as well as tricalcium phosphate, calcium pyrophosphate and calcined aluminum oxide. When an additional polishing agent is present, the amount of polishing material in the dentifrice can be at most about 75% by weight, preferably 30-55% by weight, based on the dentifrice.

When chloroform is present in the formulation, it is used in a non-toxic amount effective to flavor the dentifrice. However, since chloroform in combination with the siliceous polishing agent results in instability and corrosion in the presence of an unlined aluminum surface, such chloroform-containing formulations also incorporate an appropriate stabilizing amount of an anionic phosphate ester mixture.

The chloroform may be present in an amount of, calculated on the dental agent, no more than about 0.2 wt% and up to 8 wt% or more.

An amount of 0.5-3.5 wt% chloroform is preferred.

It should be noted that, in view of the toxic properties of large quantities of chloroform soranlge countries, legal boundaries 5 have been established, or are in the process of being established, for the maximum amount of chloroform that can be used in products such as dentifrices, with a safety margin provided by not getting too close to the toxic threshold. However, even when such legal maximums are given, the effect of the stabilizing phosphate ester 10 can be observed when non-toxic amounts, such as 8 wt%, 5 wt%, 3.5 wt%, 0.5 wt. % or 0.2% by weight of chloroform are present.

The anionic phosphate esters are mixtures of mono- and diesters with the aforementioned formiales. Suitable esters are available from MoDo Kemi Aktiebolaget, formerly Berol Aktiebolaget, Sweden, under the name BEROL (BEROL is a trademark) and may also include an anionic triSster moiety, as well as a minor nonionic moiety. BEROL 729 has alkyl chain lengths of 6-18 carbon atoms and contains series of 4 ethylene oxide units. BEROL 729 is generally used in neutralized or partially neutralized form.

Other anionic phosphate esters which are used in acid or neutralized form are BEROL 525, which contains alkyl groups of 10-18 carbon atoms and series of 5 ethylene oxide units, and BEROL 513, which also contains alkyl groups of 16-18 carbon atoms. However, BEROL 525 is also preferred in neutralized or partially neutralized form. Other BEROL type anionic phosphate esters are available as BEROL 521, BEROL 724 and BEROL 733. The weight ratio of monoester to diester can range, usually from about 1:10 to 10: 1.-

When the acidic forms of the anionic phosphate esters surfactants are neutralized or partially neutralized, alkali metal, preferably sodium or ammonium cations are present.

Desirably, the stirred slurry pH of the finished dentifrice is between 6.5 and 8 and is preferably 6.5 - 7.5.

J

The preferred anionic phosphate ester is BEROL 513.

If present, the anionic phosphate ester is used in an amount of up to about 5% by weight, which is effective at 82 0 4 5 1 6 -.........--- ------ ----- '-4-;' - 7 '. v stabilize the dentifrice in a non-lined aluminum tube. This amount may be about 0.05% and will depend, in part, on the amounts of chloroform and siliceous polishing agent present. For example, with about 3.5% chloroform, it would be desirable to use about 1.5% of the anionic phosphate ester. A usual ester content is 0.1-2% by weight, preferably 0.5-1.5% by weight, based on the dentifrice.

In addition to stabilizing the dentifrice, the anionic phosphate ester also provides surfactant properties. Such surfactant properties are described in British Pat. Nos. 1,475,251 and 1,475,252.

The aforementioned dentifrice contains a large amount of a liquid carrier, which may contain water, in an amount of at least 27.5% by weight of the composition. The liquid carrier may additionally contain, or as an alternative, wetting agents such as glycerol, but, unlike conventional dentifrices having a high liquid carrier content, may make wetting agents such as sorbitol solution or propylene glycol superfluous. A mixture of water and glycerol is particularly advantageous.

The solid portion of the dentifrice carrier is a gelling agent or binder, such as hydroxyethyl cellulose or hydroxypropyl cellulose, Irish moss, tragacanth gum, sodium carboxymethyl cellulose, polyvinylpyrrolidone, xanthan, starch or water-soluble hydrophilic colloidal carboxyvinyl polymers, such as those commercially available under the names CARBOPOL 934 and 940 (CARBOPOL is a trademark). The dentifrices will contain an organic surfactant, which may or may not be replaced by the stabilizing agent anionic phosphate ester, if present.

Such an additional agent can be anionic, nonionic. cationic or ampholytic in nature, and it is preferable to use a detersive agent as the surfactant which imparts detersive and foaming properties to the dentifrice. Suitable types of such detergents are water-soluble salts of high (containing at least 12 carbon atoms) fatty acid monoglyceride monosulfates, such as the sodium salt of the mono-sulfated mono (glyceride of hydrogenated coconut oil fatty acids, high alkyl sulfates, such as sodium lauryl sulfate , alkyl aryl sulfonates, such as sodium dodecyl benzene sulfonate, olefin sulfonates, such as sodium olefin sulfonate, 82 0 4 5 1 6 "” ------------------------ ----- - 4 * -5- wherein the olefin group contains from 12 to 21 carbon atoms, high alkyl sulfoacetates, high fatty acid esters of 1,2-dihydroxypropane sulfonates and the substantially saturated high aliphatic acylamides of low (that is not more than Aliphatic aminocarboxylic acid compounds containing 4 carbon atoms, such as those containing 12 to 16 carbon atoms in the fatty acid, alkyl or acyl radicals Examples of the latter amides are N-lauroyl-sarcosine, and the sodium, potassium and ethanolamine salts from N lauroyl, N-myristoyl or N-palmitoyl sarcosine, which should be essentially free of soap or similar high fatty acid material, which tends to significantly reduce the effect of these compounds. The use of these sarcosine compounds in dentifrices is particularly advantageous since, in addition to causing some reduction in the solubility of dental enamel in acidic solutions, these substances exhibit a longer, lasting and noticeable effect in terms of. Inhibition of acid formation in the oral cavity due to carbohydrate breakdown.

Other particularly suitable surfactants include nonionics, such as condensation products of sorbitan monostearate with about 60 moles of ethylene oxide, condensation products of ethylene oxide with propylene glycol ("Pluronics" - PLURONIC is a trade mark), and amphoteric substances, such as quatemized imidazocyl derivatives , which are commercially available under the brand name MI-RANOL, such as MXRANOL C2M. Cationic surfactant germicides and antibacterial compounds, such as diisobutylphenoxyethoxyethyl-dimethyl-25-benzyl ammonium chloride, tertiary amines with a fatty alkyl group (of 12-18 carbon atoms) and 2 (poly) oxyethylene groups, which are bonded to the nitrogen atom (and usually in total 20 - 50 ethanoxy groups per molecule) and salts thereof with acids, and compounds of the structure indicated by the formula 3, in which formula R represents a 30 fatty alkyl group, usually containing 12-18 carbon atoms, and x, y and z a total of 3 or more amounts, as well as salts thereof with inorganic or organic acids, can also be used.

The total amount of surfactant, including the anionic phosphate ester, if present, is usually no more than about 5%.

In certain forms of this invention, in the oral composition, a fluorine-providing compound is present in addition to the monofluorophosphate source. These compounds may be slightly or completely in water 820 4 5 1 6 ...... ...—---—------------- *. "·» ".

-6- are soluble. They are characterized by their ability to release fluoride ions in water and by being substantially free of reaction with other compounds of the oral preparation. These include organic amine fluorides, such as cetylamine hydrofluoride and bis (hydroxy: 5 ethyl) aminopropyl N-hydroxyethyl octadecyl amine dihydrofluoride or inorganic fluoride salts, such as suitable alkali and alkaline earth metal salts, and salts of heavy metals, for example, sodium fluoride, potassium fluoride, ammonium fluoride, a copper fluoride, such as cuprofluoride, zinc fluoride, a tin fluoride, such as stannous fluoride or stannous chlorofluoride, sodium fluorosilicate, ammonium fluorosulfonate and fluorophosphonate, aluminum monofluorophosphate. Alkali metal and tin fluorides are preferred. A mixture of sodium fluoride and sodium monofluorophosphate is also highly desirable.

The amount of the fluorine-providing compound depends to some extent on the type of compound, its solubility and the type of oral preparation, but it must be a non-toxic amount.

It is to be understood that an amount of such a compound which, by weight of the composition, liberates up to 1% by weight of fluoride ion 20 is sufficient. Any suitable minimum amount of such a compound may be used, but it is preferable to use sufficient compound to 0.005 wt% to 1 wt% in. especially to release about 0.1 wt% fluoride ion. Usually, in the cases of alkali metal fluoride and stannous fluoride, this component is present in an amount of up to 2% by weight, and preferably 0.05-1% by weight, based on the weight of the preparation.

Antibacterial agents can also be present, usually in an amount of 0.01-5% by weight. Examples of antibacterial agents include N * - (4-chlorobenzyl) -N ^ - (2,4-dichlorobenzyl) biguamide; p-chlorophenyl biguanide; 4-chlorobenzhydryl biguanide; 4-chlorobenzhydrylguanylurea; N-3-lauroxypropyl-N-p-chlorobenzyl biguanide; 1,6-di-p-chlorophenylbiguanidohexane; (chlorhexidine); 1,6-bis (2-ethylhexylbiguanido) hexane; 1- (lauryl dimethylammonium) -8- (p-chlorobenzyldimethylammonium) octane dichloride; -820 4 5 1 6 ------------——----------- · '- ·. ·.,'. * * 'It. ~ 7-5,6-dichloro-2-guanidlnobenzlmidazole? N-p-chlorophenyl-N-lauryl biguanide; 1,5-ami-1,3-bis- (2-ethylhexyl) -5-methylhexahydropyrimidine; and the non-toxic acid addition salts thereof.

Various other substances can be included as additives in the oral® preparations according to the invention. Examples are colorants or whiteners, preservatives, silicones, chlorophyl compounds and anhydrous derivatives such as urea, diammonium phosphate and mixtures thereof.

Where present, these additives are included in the compositions in amounts which do not significantly affect the desired properties and characteristics. Whitening agents, such as titanium dioxide or zinc oxide, usually in an amount of 0.2-1% by weight, give the dentifrice a particularly beautiful cosmetic appearance.

If any chloroform is used, the dentifrice will normally contain flavoring and / or sweetening. Examples of suitable flavor-enhancing ingredients are flavor-enhancing oils, for example, oils of stag, peppermint, wintergreen, sassafras, cloves, sage, eucalyptus, marjoram, cinnamon, lemon and orange, as well as methyl-20 salicylate. Suitable sweeteners include sucrose, lactose, maltose, sorbitol, sodium cyclamate, perillartine and saccharin. It is recommended that the flavor enhancers and sweeteners together amount to 0.01-5% or more of the composition.

The dentifrice is usually prepared by dispersing the polishing agent (and, if chloroform is required, the phosphate ester) in the dentifrice carrier and other components (except the chloroform) and then venting the mixture, after which each is incorporated amount of chloroform can be introduced in a closed vacuum system.

Then the dentifrice is placed in an aluminum tube.

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Due to the stability of the blends to aluminum, the inner surface of the aluminum tube need not be lined so that the tubes can be unlined aluminum tubes.

However, the stability of the mixture is advantageous even when lined tubes are used, because in this case gas development from such tubes, in which the liner is defective or damaged during use, thereby exposing the aluminum surface, is prevented. 0 4 5 1 6 · .......-- —---------: -

5 V.

-8- avoided. The invention also permits the use of its chloroform-containing embodiments in tubs using, while lined, liners into which chloroform or its decomposition products can penetrate.

The invention can be practiced in various ways and a special embodiment will be described to further illustrate the invention with reference to the accompanying example.

All amounts and ratios 10 given in this specification are weight amounts and weight ratios unless otherwise indicated.

Example.

The dentifrice formulation given in Table A was prepared in the usual manner by mixing the ingredients together and allowing them to gel with water for 15 minutes at 45 - 50 ° C, after which the gelled mixture was mixed to adequately store the powders disperse.

The table shows the composition and initial properties of the dentifrice formulation.

The pH measurements of solids in the form of slurries may be subject to variation depending on how the slurry is made and therefore preference is given to describing the pH measurement technique employed herein.

Both for the sodium aluminum silicate (NAS) and for the dentifrice formulations, the pH values were measured using a KENT pH-25 meter, Model No. 7060, using an ORION combination electrode, which is at pH 9.2 + 0.1 at 20 ° C using a borate buffer from British Drug Houses and at pH 7.0 + 0.1 at 20 ° C use of BDH phosphate buffer was calibrated.

Then, the pH was determined at 20 ° C, a 20% aqueous slurry of the test material in distilled water was prepared and stirred for 10 minutes using a magnetic stirrer. A pH measured in this manner is referred to herein as a stirred slurry pH.

With regard to the data in Table A, the following points are pointed out.

35 Note 1.

The sodium carboxymethyl cellulose is of 7 MP quality.

Note 2.

The given percentage of soluble fluoride is equal to (the average 82 0 4 5 1 6 - - -9- 2 of 2 readings) x 10, i.e. in Table A a number of 10 has an average fluoride content of 0.10 means.

Note 3.

The pH for the dentifrice was measured immediately after the dentifrice was prepared.

The dentifrice formulations given in the table were placed in unlined aluminum tubes in the usual manner.

10 TABLE A.

Component Quantity

Glycerol: 25.00 Sodium carboxymethyl cellulose (1): 1.00

Titanium dioxide: 0.40

Accharine sodium: 0.18

Sodium Monofluorophosphate: 0.76

Soluble fluoride (2),%: 10.7 Water: 42.16

Sodium aluminosilicate (NAS): 24.00 NAS type: Dentolex 644 NAS pH: 5.8

Sodium lauryl sulfate: 1.50. Water: 4.00

Naked dust: 1.00 pH of dentifrice (3): 6.6

The dentifrice formulation of the example showed good aging in the 30 unlined aluminum tubes for a period of Vein 3 months at 43 ° C, and although it contained some hard lumps during this whole period and a small amount at the end of that period showed yellowing, there was no gas evolution.

This clumpiness is attributed to the presence in the Dentolex 644 type NAS material of some particles having oversized dimensions and this problem may be solved by screening this NAS material. .

Dentolex 644 is available from Zeofinn Oy, Hainina, Finland, 8 20 4 5 1 6 "" _ -10- while the supplying company describes this product with the following characteristics: chemical composition: sodium silicon aluminate 5 main particle diameter: 0.016 micrometre moisture loss: not more than 7% when heated to 105 ° C for 2 hours

density: 2.0 g / cm 2 at 25 ° C

3 bulk density: 300 kg / m, whipped 10 oil absorption: 170 ml oil / 100 g refractive index: 1.47 at 20 ° C.

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8204516

Claims (19)

A stable dentifrice containing an aqueous, dentally acceptable oral carrier, wherein at least 27.5% by weight of the dentifrice is water, and in said oral carrier, based on the dentifrice, 10-40% by weight. % of an acidic siliceous polishing agent 5 having a stirred slurry pH (as further defined) of from 5.0 to less than 6.5 and which dentifrice further contains a stabilizing amount of a monofluorophosphate ion, the dentifrice having a stirred slurry pH of 5.5-8. 2. A stable! dentifrice according to claim 1, also comprising a non-toxic amount of, based on the dentifrice, at least 0.2 wt.% chloroform and, calculated on the dentifrice, 0.05-5 wt.% of a stabilizing anionic phosphate ester mixture wherein the mixture consists of a monoester of formula 1 and a diester of formula 2, wherein R represents an alkyl group of 10 to 20 carbon atoms; n is a number from 1 to 6; and M represents hydrogen, alkali metal or ammonium. A dentifrice according to claim 2, wherein the chloroform is present in an amount, based on the dentifrice, of 0.5-3.5% by weight. A dentifrice according to claim 3, wherein the chloroform is present in an amount, based on the dentifrice, of 0.5% by weight. A dentifrice according to any one of claims 2-4, wherein the R group in the anionic phosphate ester mixture contains 16-18 carbon atoms and the weight ratio of monoester to diester is about 1:10 to 10: 1. A dentifrice according to any one of claims 1 to 5, wherein the dentifrice contains at least 30% by weight of water. A dentifrice according to claim 6, wherein the dentifrice contains 35-60% by weight of water. A dentifrice according to claim 7, wherein the dentifrice contains 40-55% by weight of water. A dentifrice according to any one of claims 1-8, wherein the silicon-containing polishing agent contains a alkali metal aluminum silicate. A dentifrice according to any one of claims 1-9, wherein the siliceous polishing agent is present in an amount of 10-30% by weight, based on the dentifrice. A dentifrice according to claim 10, wherein the siliceous polishing agent is present in an amount of 15-25% by weight, based on the dentifrice. 12. A dentifrice according to any one of claims 1-11, wherein the stirred slurry pH of the siliceous polishing agent is 5.0-6.4. A dentifrice according to claim 12, wherein the stirred slurry pG of the siliceous polishing agent is 5.5-6.0. A dentifrice according to any one of claims 1 to 13, containing at least 0.01% monofluorophosphate ion. 15. A dentifrice according to claim 14, containing at least 0.05% monofluorophosphate ion. A dentifrice according to claim 15, containing at least 0.09% monofluorophosphate ion. 17. A dentifrice containing 35-50 wt.% Water, 0-30 wt.% Glycerol, 20-15-25 wt.% Of an alkali metal aluminum silicate polishing agent having a stirred slurry pH of 5.0-6.4, at least 0.5 wt% alkali metal monofluorophosphate, calcined alumina in an amount of 0-15 wt% and one or more organic surfactants in an amount of not more than 5 wt%, the dentifrice being a stirred slurry -pH possesses 5.5 - 8. A packaged dentifrice consisting of an unlined aluminum tube in which a dentifrice as defined in any one of claims 1 to 17 is in contact with the aluminum surface of the unlined aluminum tube. 19. A stable dentifrice, substantially as described in more detail in the example. 8204 5 1 6 ................................... ........... ........