NL8503210A - ADDRESSING TOOTH CLEANER. - Google Patents

Description

VO 7467 _l_

Astringent dentifrice.

This invention relates to a dentifrice containing a water-soluble zinc salt, which provides an astringent effect on the oral mucosa and periodontal tissue during brushing of the teeth, and optionally contains an alkali metal monofluorophosphate or a gelling agent or both. Each of the components is compatible with and substantially non-reactive with an aqueous silica gel polishing agent.

The astringent action of zinc ions provided by water-soluble zinc salts, promoting and improving oral hygiene, has long been known. Nevertheless, there have been limits to the practical use of zinc in dentifrice compositions, since zinc ions can easily react with typical dentifrice components, causing a significant loss of zinc ion availability.

Monofluorophosphate ions have also been known for a long time to promote oral hygiene and reduce caries formation by liberation of fluoride, but their performance has also been impaired by incompatibility with some dentifrice components, such as water-soluble zinc compounds.

Nonionic gelling agents, such as hydroxyethyl cellulose, are preferably used in dentifrices when a water-soluble zinc salt is used. However, when alkali metal carboxy methyl cellulose has been used in the presence of zinc ions, a reaction occurs in which zinc ions are removed, resulting in an optional gel collapse and phase separation. In ü.S. Patent No. U.S. 3,728,446 has described the in situ reaction between zinc ions and alkali metal carboxymethyl cellulose to form visible particles. Furthermore, gel-type dentifrices which provide the astringent action of zinc are limited due to their incompatibility of zinc ions with various silica containing polishing agents. Such silica containing polishing agents, such as silica xerogel, having an average particle size between about 2 and 20 microns and generally a surface area of 2 at least about 300 m / g, typically about 300-370 m / g, or 2 35 approximately 600 - 800 m / g, which in U.S. Patent No. No. 3,538,230 discloses 3: -3210 4 * -2, undergo in situ reaction with zinc ions, so that much of the theoretically available zinc is lost by physiochemical means such as absorption.

Similar compatibility problems would arise when a water-soluble zinc salt is present together with other dentifrices in the form of salt, in particular calcium salts, such as dicalcium phosphate or calcium carbonate. In fact, it was believed that it would be difficult to use water-soluble zinc salts in such conventional dentifrices and maintain a high level of zinc ion availability.

Compatibility is also a problem when an alkali metal monofluorophosphate with such a siliceous polishing agent is used in a dentifrice containing a water-soluble zinc salt.

It has therefore been difficult to prepare dentifrices containing a siliceous polishing agent and amounts of zinc ions with or without alkali metal monofluorophosphate or alkali metal carboxymethyl cellulose or both and which provide the astringent properties of zinc and the anti-oxidant properties. caries properties of fluoride ef-20 remain effective. In particular, gel-type dentifrices which provide both the astringent action of zinc with or without a fluoride anti-caries effect have not been satisfactorily available due to the incompatibility of zinc ions with monofluorophosphate and with alkali metal carboxymethyl cellulose in the presence of various siliceous polishing agents.

The present invention uses a precipitated amorphous silica gel, which is described in published British Patent Application No. 2,038,303 A and in U.S. Pat. 4,528,181. US Patent 4,528,181 discloses a dentifrice containing the precipitated amorphous silica gel and which stabilizes a dual fluoride source containing sodium fluoride and sodium monofluorophosphate and a calcium source to improve fluoride retention. by an alkali metal phytate.

Such a precipitated amorphous silica gel material is available from Grace G.m.b.H. As a product, such as Syloblanc 81, - .Ί, 1 - · _

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-3-

Svloblanc 81C and Syloblanc 82. Eet differs from the types of xero-gel sold by W.R. Grace and Co. under the trademark Syloid and which are specifically described in CJ.S. Patent No. 3,538,230. Although some products produced by Grace G.m.b.H. sold under the Syloblanc trademark, previously available or still available under the Syloid trademark, none of the Syloblanc 81, Syloblanc 81C or Syloblanc 82 brands have ever been available under the Syloid trademark. It is particularly noteworthy that the silicon dioxide gel grades used in the present invention are less sharp as the specific surface area increases, while the silica xerogel grades described in CJ.S. Patent 3,538,230 are generally sharper as their specific surface area increases.

In view of the poor compatibility of most polishes with zinc, including those in US Patent No.

3,538,230, it was quite unexpected that a particularly siliceous polishing agent will not have such a problem and further, in the presence of such a polishing agent, the reaction between zinc ions and alkali metal carboxymethyl cellulose is markedly reduced. . Furthermore, it was unexpected that in the presence of such a particularly siliceous polishing material and zinc ions, alkali metal monofluorophosphate remains stable and compatible to provide fluoride. Nevertheless, according to the present invention, it has been found that retention of high levels of astringent by zinc ions is achieved when such a special siliceous polishing material is used, regardless of whether or not alkali metal carboxymethyl cellulose is used, or monofluorophosphate is used, obtaining high levels of fluoride ions, which are also retained.

It is an advantage in this invention that an astringent dentifrice containing zinc ions is provided, which dentifrice can effectively contain monofluorophosphate or an alkali metal carboxymethyl cellulose as a gelling agent or both.

It is another advantage of this invention that a gel type astringent-gelling toothpaste containing zinc ions is provided, which toothpaste may optionally contain monofluorophosphate or an alkali metal carboxymethyl cellulose as a gelling agent or both.

-4-

Further advantages of the invention will be apparent upon consideration of the following description.

In certain aspects, this invention relates to an astringent dentifrice containing: about 20-90% by weight of a liquid carrier containing: water in an amount of at least about 3% by weight of said dentifrice, about 0.05 5% by weight of a gelling agent and about 10-50% by weight of a polishing agent, which is a synthetic precipitated amorphous silicon dioxide gel having an average particle size of 1 to 30 micro-10 meters and 2 a) a specific surface area from 1 to 600 m / g, b) a pore volume of 0.05 to 0.5 cm3 / g, c) a product of specific surface area (in m2 / g and pore volume (in cm3 / g) of less than or equal 240, 15 d) a calculated pore diameter of 1.5 to 2.5 nm, and e) a water content of less than 25% by weight; and at most about 5% of a water-soluble zinc salt, which provides at least about 50 ppm zinc ions to said dentifrice. Furthermore, said dentifrice may contain an alkali metal-carboxymethylcellulose gelling agent and / or alkali metal monofluorophosphate in an amount providing about 0.01-1% fluoride.

As indicated above, the synthetic precipitated silicon dioxide of British Patent Application Publication No. 2538303 A and U.S. Pat. Patent No. 4,528,181 described type.

Specific grades of the silicon dioxide material described therein are suitable for use in the practice of the present invention. In addition, particularly preferred specific qualities have been described in an October 30, 2008 trade publication of Grace G.m.b.H. from Norderstadt, Germany, as Sylo-blanc 81 and Syloblanc 82 with the following characteristic physical and chemical properties: * '......' * -5- SYLOBLANC 81 SYLOBLANC 82

Average particle size (according to Coulter) um 4 7

Moist sieve residue (42 µm)% 0.02 0.02 5 pH (5% suspension in water) 3 6

Specific surface area (B.E.T.) m2 / g 400 480

Drying loss% 7 4

SiO2 content (on calcined substance)% 96 99

Refractive index 1.46 1.46 10

In a variation of Syloblanc 81, which is available as Syloblanc 81C, the pH (5% suspension in water) is about 6-8.

Syloblanc 81 and in particular 81C are very effective in polishing tooth surfaces. Syloblanc 82 has a lower polishing effect, but can be used by consumers who desire such a reduced effect. Also, grades of silicon dioxide material can be proportioned into mixtures, thereby obtaining suitable polishing characteristics. It is noteworthy that the dentifrices in non-internally coated aluminum dentifrice tubes, even in the absence of phytate salt, used in the invention described in U.S. Pat. Patent No.

4,528,181 has been described, is necessary, compatible. The precipitated amorphous silica gel is used in a gel dentifrice in an amount of about 10-50% by weight, especially about 10-40% by weight.

Hydrous slurries of the silicon dioxide materials (e.g., about 5 to 20% slurries) are typified by a pH of about 2 to 9. Since the dentifrice composition of the present invention preferably has a pH (measured in a 10% hydrous slurry) of at least about 5.5, e.g. about 5.5-7.5, wherein the pH of the dentifrice can be adjusted with a suitable material such as sodium hydroxide, etc.

The water-soluble zinc salt is present in the dentifrice in an amount of up to about 5% by weight, preferably about 0.01-3% by weight, and in particular about 0.1-2% by weight.

Water-soluble zinc salts of the present invention are water-soluble at least about 10% by weight, preferably at least 20% by weight. At least about 50 ppm zinc ions are provided to the dentifrice, preferably at least about 750 ppm and especially at least about 1000 ppm zinc ions. Suitable zinc salts include zinc sulfate, zinc chloride, zinc 5 bromide, zinc iodide, zinc nitrate and zinc acetate. In the case of zinc chloride, 0.01% by weight provides about 50 ppm of zinc ions, while 0.2% by weight provides about 1000 ppm of zinc ions. 0.48 wt% zinc sulfate heptahydrate provides about 1000 ppm zinc ions. In addition, zinc oxide, sparingly soluble (less than 0.0005%) zinc compound, can also be added to prevent pH reduction in the product. This acts as a buffer system and improves pH stability and compatibility in aluminum tubes that are not coated on the inside. It can be present in an amount of about 0.005-0.5 wt%.

The dentifrice contains a liquid carrier containing about 3-60% by weight of water, usually mixed with at least one wetting agent.

The liquid phase accounts for about 20-90% by weight of the dentifrice, and is generally about 25-80% by weight of liquid, typically about 3-50% by weight, preferably 3-10% by weight, of water , in a substantially clear gelled dentifrice or gelled dentifrice, which would be substantially clear except for the presence of a haze, such as titanium dioxide, and is about 11-50% by weight in a hazy to cloudy gelled dentifrice with about 10 90 wt%, preferably about 15 - 80 wt% wetting agent. Typical wetting agents include glycerol, sorbitol (e.g., 70% solution), mannitol, polyethylene glycol with a molecular weight of about 400-600, propylene glycol and mixtures thereof.

The dentifrice also contains a gelling agent or binder as a solid carrier, although it may be present in a small amount, since the synthetic precipitated silica produces a thickening or gelling of the dentifrice to a creamy or pasty consistency. bring. Alkali-35 metal carboxymethyl cellulose is preferred in one aspect of this invention, but other gelling agents or binders, which may be present, include hydroxyethyl cellulose, hydroxypropyl cellulose, xanthan, Irish moss, iota carrageenan, tragacanth gum , polyvinyl-pyrrole idon, starch and mixtures thereof. Such gelling agents can be used in an amount of about 0.05-5 wt%, usually about 0.05-2 wt%, and preferably about 0.1-1.5 wt%. The use of sodium carboxymethyl cellulose is particularly desirable.

Alkali metal monofluorophosphate, such as sodium and potassium monofluorophosphate, is compatible in the dentifrice. Sodium mono-10 fluorophosphate is particularly preferred. In the past, when attempts were made to formulate a dentifrice with a liquid carrier, gelling agent, polishing agent, zinc salt and sodium monofluorophosphate, significant concentrations of zinc ions and fluoride ions were lost due to insolubilization. Unexpectedly, when the polishing agent is the described synthetic precipitated amorphous silicon gel, high concentrations of fluoride ions and significant retention of zinc ions are achieved. Such high concentrations of fluoride retention are not achieved when a simple fluoride such as sodium fluoride is used.

Sodium monofluorophosphate, Na 2 PO 4 F, as commercially available, can vary considerably in purity. It can be used in any suitable purity, provided that any impurities do not significantly affect the desired properties. Generally, the desired purity is at least 80 wt%, and preferably at least 90 wt%, of sodium monofluorophosphate, the remainder primarily consisting of impurities or by-products of the preparation such as sodium fluoride and in water soluble sodium phosphate salt. In other words, the sodium monofluorophosphate used should have a total fluoride content of more than 12%, preferably 12.7% and a content of not more than 1.5%, preferably not more than 1.2% to free sodium fluoride; while the sodium monofluorophosphate content is at least 12%, preferably at least 12.1%, calculated as fluoride. Alkali metal monofluorophosphate is present in an amount to provide fluoride in an amount of about 0.01-1 wt%, preferably about 0.1 wt%. For example, sodium monofluorophosphate may be present in an amount of about 0.076-7.6%, preferably 0.76%, which corresponds to about 100-10000 ppm fluoride, preferably about 1000 ppm.

Any suitable surfactant or detersive material can be included in the dentifrice compositions. Such compatible materials are desirable to provide additional detersive foaming and anti-bacterial properties depending on the specific surfactant type and are selected accordingly. These detergents are usually water-soluble compounds and can be anionic, nonionic, amphoteric or cationic in structure. It is usually preferred to use the water-soluble detergents of the non-soap type or synthetic organic detergents. Suitable detersives are known and include, for example, the water-soluble salts of high fatty acids and mono-glyceride monosulfate detergents (eg sodium coconut fat-fatty acid monoglyceride monosulfate), high alkyl sulfate (eg sodium lauryl sulfate) alkyl aryl sulfonate (e.g. sodium dodecyl benzene sulfonate, high fatty acid esters of 1,2-dihydroxypropane sulfonate) and the like.

Other surfactants include the substantially saturated high aliphatic acylamides of low aliphatic amino carboxylic acid compounds, such as those having 12 to 16 carbon atoms in the acyl moiety. The amino acid portion is generally derived from the low aliphatic saturated monoaminocarboxylic acid compounds. Suitable compounds are the fatty acid amides of glycine, sarcosine, alanine, 3-aminopropanoic acid and valine having about 12 to 16 carbon atoms in the acyl group. Preferably, however, the N-lauroyl, myristoyl and palmitoyl sarcoside compounds are used for optimal effects.

The amide compounds can be used in the form of the free acid or, preferably, as their water-soluble salts, such as the alkali metal, ammonium, amine and alkylolamine salts. Specific examples thereof are the sodium and potassium N-lauroyl, myristoyl and palmitoyl sarcosides, ammonium and ethanolamine N-lauroyl glycide and alanine. For convenience, reference to "aminocarboxylic acid compound", "sarcoside" and the like herein refers to such compounds which have a free carboxylic acid group or the water-soluble carboxylate salts.

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Such materials are used in pure or substantially pure form. They should be as free as practicable from soap or the like high fatty acid material which tends to reduce the activity of these compounds. In conventional practice, the amount of such a high fatty acid material is less than 15% by weight of the amide and insufficient to adversely affect it and preferably less than about 10% of said amide material.

Other particularly suitable surfactants include nonionic agents such as condensation products of sorbitan monostearate with about 20 moles of ethylene oxide, condensation products of ethylene oxide with propylene oxide, condensation products of propylene glycol ("Pluronic" materials), and amphoteric agents such as ( alkyl) -amide-alkylene-alkylated long-chain amine derivatives available under the trademark "Miranol" Cationic surfactant germicides antibacterial compounds, such as diisobutylphenoxyethoxyethyl dimethyl benzyl ammonium chloride, benzyl dimethyl -stearyl ammonium chloride, tertiary amines with a fatty alkyl group (from 12 to 18 carbon atoms) and two (poly) oxyethylene groups, which are bonded to the nitrogen (and usually a total of about 2 to 50 ethanoxy groups per molecule and salts thereof with acids, and compounds of the structure indicated by the formula 1, wherein R represents a fatty alkyl group having about 12 to 18 carbon atoms and x, y and z totaling 3 or higher, as well as salts thereof with inorganic or organic acids, may also be used. It is preferable to use about 0.05 to 5% by weight of the aforementioned surfactants in the oral composition of the present invention.

Several other substances can be included in the dental creams of this invention. Examples thereof are cloudings, preservatives, stabilizers, silicones, chlorophyll compounds and ammonia-derived substances such as urea, diammonium phosphate and mixtures thereof. These adjuvants are included in the compositions herein in amounts which do not significantly adversely affect the desired properties and characteristics and are suitably selected and used in conventional amounts.

For some purposes, it may be desirable to be antibacterial

*** · - «t * *. · *’ ♦ · V

To include -10 agents in the compositions of the present invention. Typical antibacterial agents, which may be used in an amount of from about 0.01 wt% to about 5 wt%, preferably from about 0.05 to about 1.0 wt%, of the tooth cleaning composition are inter alia cetylpyridinium chloride, benzethonium chloride, as well as: N 4 (chlorobenzyl) -1- (2,4-dichlorobenzyl) biganide; p-chlorophenyl biguanide; 4-chlorobenzhydryl biguanide; 4-chlorobenzhydrylguanylurea; N-3-lauroxypropyl-N-p-chlorobenzyl biguanide; 1,6-di-p-chlorophenyl biguanidohexane; 1- (lauryldimethylammonium) -8- (p-chlorobenzyldimethylammonium) -5,6-dichloro-2-guanidinobenzimidozole; N * -p-chlorophenyl-N-lauryl biguanide; 5-amino-1,3-bis (2-ethylhexyl) -5-methylhexahydropyrimidine; and their non-toxic addition salts.

Any suitable flavoring or sweetening agent may be used in formulating a flavor for the compositions of the present invention. Examples of suitable flavoring ingredients include the flavoring oils, for example, spearmint ("spearmint"), peppermint, wintergreen, sassafras, clove, sage, eucalyptus, marjoram, cinnamon, lemon, and orange, as well as methyl salicylate. Suitable sweeteners include sucrose, lactose, maltose, sorbitol, sodium cyclamate, sodium saccharin, dipeptides of U.S. Patent 3,939,261, and oxathiazine salts of U.S. Patent 3,932,606. Suitable flavoring and sweetening agents together may comprise about 0.01 to 5% or more of the composition.

The dentifrice is packaged in a container from which it can be easily extruded, such as a pressure differential dental cream dispenser or a mechanically controlled dental cream dispenser or an internally coated aluminum tube or an internally waxed lead tube or plastic tube, which can be laminated with aluminum. The rheological properties are highly desirable when a mechanically operated dispenser of the type described in British Patent Application 2,070,695A, published September 9, 1981, is used. This administration container contains an 8 s ·· 1 0 1 * -5 '-11 administration nozzle, a clamping body, a central rod, a plunger and a hand control for operation.

The pressure differential administration container can be of the aerosol or vacuum type. Suitable differential pressure delivery devices 5 include those which include a collapsible product-containing bag disposed within a rigid container containing a propelling fluid. In such administration containers, the action of the valve allows the release of only the product, the propellant fluid being separated from the product by the fluid impermeable bag. Delivery devices of this type are described in U.S. patents 3,828,977 and 3,838,796.

These are the so-called Sepro delivery devices. Pressure is also applied to the so-called Exxel and Enviro spray holders.

Yet another type of delivery device is the locking piston-15 container, which is in U.S.A. U.S. Patent 4,171,757 has been described. Such a container comprises a valve, a product-containing compartment and an essentially fluid-tight barrier piston, which separates the propelling fluid from the product present (the so-called Diamond container).

The dentifrice is generally prepared by pre-forming a mixture of the gelling agent with the liquid carrier components, eg water and wetting agent, which may also contain additional ingredients, such as the monofluorophosphate and / or sweetener, and thus the synthetic, mixing precipitated silica gel and the zinc salt. Ingredients which are used extra can then be added.

Although the invention has been described with reference to the illustrative examples, it will be apparent to those skilled in the art that various modifications can be made therein which are within the scope of protection. All amounts are by weight unless otherwise indicated.

> v. . - <-12- EXAMPLE · Ι

The following cloudy gel dentifrices were prepared and placed in non-internally coated aluminum tubes:

5 A B

Glycerol 25,000 25,000

Sorbitol (70%) 47,050 43,830

Xanthan 0.260 0.260

Sodium saccharin 0.170 0.170 10 Titanium dioxide 1,000 1,000

Water 3,000 3,000

Zinc sulfate heptahydrate 0.480 0.480

Precipitated amorphous SiO2 ~ gel * 20,000

Si02-xerogel ** - 17,000 15 Si02 ~ airgel *** - 6,500

Sodium hydroxide (40%) 0.280 *. Sodium lauryl sulfate 1,760 1,760

Flavoring 1,000 1,000 pH (20% slurry) 5.9 6.1 20 * Syloblanc 81 available from Grace G.m.b.H .; ** Syloid ALL available from Grace G.m.b.H., previously known as Syloid 63; *** Syloid-244 thickener available from W.R. Grace & Co.

The theoretical amount of soluble zinc ions in each gel-25 dentifrice was 1000 ppm or 0.100%.

Dental cleaner A did not require the presence of a thickener to provide the desired gel character. Its consistency was approximately equivalent to that of dentifrice B.

Each dentifrice was aged at ambient temperature and at 43 ° C. Both generally maintained the same desired consistencies. The amounts of available soluble zinc ions in each dentifrice expressed as a percentage were found to be as follows: "-"> i ». · - -" "y» 2 +2 -13-, ......

% Zn ambient temperature _43 ° C_ at the 13 2 13 beginning of month months weeks month months

Dental cleaner A 0.084 0.080 0.050 0.091 0.070 0.050 5 Dental cleaner B 0.054 0.042 0.005 0.049 0.048 0.005

Dentifrice A containing Syloblanc 81 maintained excellent levels of soluble zinc ions compared to the otherwise generally equivalent dentifrice B containing Syloblanc AL1.

Similar excellent retention levels of soluble zinc ions were achieved when Syloblanc 81 of the dentifrice A was replaced by Syloblanc 82 and a 1: 1 mixture of Syloblanc 81 and 82, with each of these cases being reduced or omitted to sodium hydroxide, their amounts of sorbitol (70%) were added.

Excellent retention levels of soluble zinc ions were also achieved when Syloblanc 81 was replaced by Syloblanc 81C, the amount of which was added to sorbitol (70%) with omitted sodium hydroxide.

In each of the dentifrices A and B, 0.25 dl of zinc oxide was incorporated in place of the corresponding amounts of sorbitol, stabilizing the pH during aging and improving compatibility with uncoated aluminum tubes for extended periods of time .

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EXAMPLE II

The following cloudy gel dentifrices were prepared and placed in non-internally coated aluminum tubes:

5 A B

Glycerol 25,000 25,000

Sorbitol (70%) 47,050 43,550

Sodium carboxymethyl cellulose 0.260 0.260

Sodium saccharin 0.170 0.170 10 Titanium dioxide 1,000 1,000

Water 3,000 3,000

Zinc sulfate heptahydrate 0.480 0.480

Precipitated amorphous SiO2 ~ gel * 20,000

SiO-xerogel ** - 17,000 15 SiO-xerogel *** - 6,500

Sodium hydroxide (40%) 0.280 0.280

Sodium lauryl sulfate 1,760 1,760

Flavoring 1,000 1,000 pH (20% slurry) 5.9 6.1 20 *; **; *** - see example I.

The theoretical amount of soluble zinc ions in each gel dentifrice was 1000 ppm or 0.100%.

Dental cleaner A did not require the presence of a thickener to provide the desired gel character initially.

Each dentifrice was aged at ambient temperature and at 43 ° C. Both generally maintained equivalent desired consistencies. The percentage amounts of the available soluble zinc ions in each dentifrice were found to be as follows: +2% Zn ambient temperature _43 ° C_ at the 13 2 13 beginning month months weeks month months

Dental cleaner A 0.080 0.079 0.050 0.082 0.069 0.050

Dental cleaner B 0.052 0.039 0.002 0.050 0.060 0.002 Λ:. ; :. ;

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-15-

Dentifrice A containing Syloblanc 81 retained the gel character and excellent levels of soluble zinc ions compared to the otherwise generally equivalent dentifrice B containing Syloblanc 63. When the usual grade 7 MXF sodium-5 carboxymethylcellulose was used, there was phase separation and collapse in the presence of Syloid 63 as a polishing agent, which did not occur when Syloblanc 81 was used c

It should be remembered that the evaluation levels of the two-week and 10-month aging dentifrice B at 43eC represent routine experimental variations.

Similar excellent retention levels of soluble zinc ions were achieved when Syloblanc 81 of dentifrice A was replaced by Syloblanc 82 and a 1: 1 mixture of Syloblanc 15 81 and 82, with either of the reduced or omitted sodium hydroxide contents in each case, their amounts of sorbitol (70%) were added.

Excellent retention levels of soluble zinc ions were also achieved when Syloblanc 81 was replaced by Syloblanc 81C, where 20 was added to sorbitol (70%) in its amount with sodium hydroxide omitted.

In each of the dentifrices A and B, 0.25 dl of zinc oxide was incorporated instead of corresponding amounts of sorbitol, stabilizing the pH during aging and improving compatibility with non-coated aluminum tubes for extended periods of time .

».

EXAMPLE III

The following cloudy gel dentifrices were prepared and placed in non-internally coated aluminum tubes:

5 A B

Glycerol 25,000 25,000

Sorbitol (70%) 46.340 46.880

Sodium carboxymethyl cellulose 0.190 0.190

Sodium saccharin 0.170 0.170 10 Titanium dioxide 1,000 1,000

Water 3,000 3,000

Zinc sulfate heptahydrate 0.480 0.480

Sodium monofluorophosphate 0.760

Sodium Fluoride - 0.220 15 Precipitated Amorphous SiO2 ~ Gel * 20,000 20,000

Sodium hydroxide (40%) 0.300 0.300

Sodium lauryl sulfate 1,760 1,760

Flavoring 1,000 1,000 pH (20% slurry) 6.0 .5.9 20 * - See Example I.

The theoretical amounts of soluble zinc ions and fluoride for both the zinc ions and the fluoride in each gel dentifrice were 1000 ppm or 0.100%.

Each dentifrice was aged at ambient temperature and at 43 ° C. The percentages of available soluble zinc ions and of fluoride in each dentifrice at ambient temperature were found to be as follows: +2 -17% Zn; % monofluorophosphate as fluoride (dentifrice A); % fluoride (dentifrice S)

Ambient temperature Initial One month 5 Dental cleaner A 0.66 Zn 0.066 Zn

0.096 F 0.097 F

Dental cleaner B 0.070 Zn 0.051 Zn

0.100 F 0.048 F

The dentifrice A, which contained sodium monofluorophosphate, provided significant retention of both zinc ions and fluoride, compared to dentifrice B containing sodium fluoride. At 43 ° C, gas formed in the non-internally coated aluminum tube containing dentifrice B while the non-internally coated aluminum tube containing dentifrice A remained stable.

The zinc ion and fluoride retention were low when the xerogel

Syloid 63, which was available from W.R. Grace & Co. it replaced Syloblanc 81.

Similar results to those determined with dentifrice A were achieved when potassium monofluorophosphate was used in place of sodium monofluorophosphate.

Similar excellent retention levels of soluble zinc ions and fluoride were achieved when Syloblanc 81 of dentifrice A was replaced by Syloblanc 82 and a 1: 1 mixture of Syloblanc 81 and 82, in each case reducing their amounts upon reduction of omitting the sodium hydroxide contents, sorbitol (70%) was added.

Excellent retention levels of soluble zinc ions and fluoride were also achieved when Syloblanc 81 was replaced by Syloblanc 81C, the amount of which was added to sorbitol (70%) with sodium hydroxide omitted.

In each of the dentifrices A and B, 0.25 dl of zinc oxide was incorporated instead of corresponding amounts of sorbitol, stabilizing the pH during aging and improving compatibility with non-coated aluminum tubes for extended periods of time .

* -18-

EXAMPLE IV

The following stable, visually clear gel-shaped dentifrices were prepared and placed in non-internally coated aluminum tubes:

5 A B C D

Glyrerol 25,000 25,000 25,000 25,000

Sorbitol (70%) 48,310 48,590 48,590 48,450

Xanthan 0.260 0.260 0.260 0.260

Sodium saccharin 0.170 0.170 0.170 0.170 10 Water 3.000 3.000 3.000 3.000

Zinc chloride 0.020 0.020 0.020 0.020

Syloblanc 81 20,000 - - 10,000

Syloblanc 81C - 20,000

Syloblanc 82 - 20,000 10,000-15 Sodium Hydroxide (40%) 0.280 - 0.140

Sodium lauryl sulfate 1,760 1,760 1,760 1,760

Flavoring 1,000 1,000 1,000 1,000

Blue color solution (1%) 0.200 0.200 0.200 0.200. - ♦ s.

... .. '!> -19-

EXAMPLE V

The following stable, visually clear gel-shaped dentifrices were prepared and placed in internally uncoated aluminum tubes:

5 A B C D

Glycerol 25,000 25,000 25,000 25,000

Sorbitol (70%) 48,310 48,590 48,590 48,450

Sodium carbboxymethyl cellulose 0.260 0.260 0.260 0.260

Sodium saccharin 0.170 0.170 0.170 0.170 10 Water 3.000 3.000 3.000 3.000

Zinc chloride 0.020 0.020 0.020 0.020

Syloblanc 81 20,000 - - 10,000

Syloblanc 81C - 20,000

Syloblanc 82 - 20,000 10,000 15 Sodium Hydroxide (40%) 0.280 - 0.140

Sodium lauryl sulfate 1,760 1,760 1,760 1,760

Flavoring 1,000 1,000 1,000 1,000

Blue color solution (1%) 0.200 0.200 0.200 0.200

Similar stability was achieved when potassium carboxy-methyl cellulose was used in place of sodium carboxymethyl cellulose.

X, - ^ -20-

EXAMPLE VI

The following stable, visually clear gel-shaped dentifrices were prepared and placed in internally uncoated aluminum tubes:

5. A B C D

Glycerol 25,000 25,000 25,000 25,000

Sorbitol (70%) 47,550 47,830 47,830 47,690

Xanthan 0.260 0.260 0.260 0.260

Sodium saccharin 0.170 0.170 0.170 0.170 10 Water 3.000 3.000 3.000 3.000

Sodium monofluorophosphate 0.760 0.760 0.760 0.760

Zinc chloride 0.020 0.020 0.020 0.020

Syloblanc 81 20,000 - - 10,000

Syloblanc 81C - 20,000 15 Syloblanc 82 - - 20,000 10,000

Sodium hydroxide (40%) 0.280 - 0.140

Sodium lauryl sulfate 1,760 1,760 1,760 1,760

Flavoring 1,000 1,000 1,000 1,000

Blue color solution (1%) 0.200 0.200 0.200 0.200. I, i / ¾. -:. ·! i ij -21-

EXAMPLE VII

The following hazy and cloudy gel dentifrices were prepared and packaged in mechanically operated dispensers:

5 A B C D

Glycerol 25,000 25,000 25,000 25,000

Sorbitol (70%) 24,970 24,870 24,870 24,870

Iota carrageenan 0.700 0.700 0.700 0.700

Sodium saccharin 0.170 0.170 0.170 0.170 10 Water 25,000 25,000 25,000 25,000

Zinc bromide dihydrate 0.400 -

Zinc iodide - 0.500

Zinc nitrate hexahydrate - - 0.500

Zinc Acetate Dihydrate - - - 0.500 15 Syloblanc 81C 21,000 21,000 21,000 21,000

Sodium lauryl sulfate 1,760 1,760 1,760 1,760

Flavoring 1,000 1,000 1,000 1,000

In the examples, sodium cyclamate could be used instead of sodium saccharin.

· »" *.

-22-

EXAMPLE VIII

The following stable hazy and cloudy gel-type dentifrices were prepared and placed in non-internally coated aluminum tubes:

5 Ά B C D

Glycerol 25,000 25,000 25,000 25,000

Sorbitol (70%) 24,970 24,870 24,870 24,870

Sodium carboxymethyl cellulose 0.700 0.700 0.700 0.700

Sodium saccharin 0.170 0.170 0.170 0.170 10 Water 25,000 25,000 25,000 25,000

Zinc bromide dihydrate 0.400 -

Zinc iodide - 0.500 - -

Zinc nitrate hexahydrate - - 0.500

Zinc Acetate Dihydrate - 0.500 15 Syloblanc 81C 21,000 21,000 21,000 21,000

Sodium lauryl sulfate 1,760 1,760 1,760 1,760

Flavoring 1,000 1,000 1,000 1,000

In the examples, sodium cyclamate could be used instead of sodium saccharin.

:. J

-23-

EXAMPLE IX

The following stable hazy and cloudy gel-shaped dentifrices were prepared and packaged in mechanically operated dispensing containers:

5 A B C D

Glycerol 25,000 25,000 25,000 25,000

Sorbitol (70%) 24,210 24,110 24,110 24,110

Iota carrageenan 0.700 0.700 0.700 0.700

Sodium saccharin 0.170 0.170 0.170 0.170 10 Water 25,000 25,000 25,000 25,000

Sodium monofluorophosphate 0.760 0.760 0.760 0.760

Zinc bromide dihydrate 0.400 -

Zinc iodide - 0.500

Zinc nitrate hexahydrate - - 0.500 Zinc acetate dihydrate - 0.500

Syloblanc 81C 21,000 21,000 21,000 21,000

Sodium lauryl sulfate 1,760 1,760 1,760 1,760

Flavoring 1,000 1,000 1,000 1,000

In the examples, sodium cyclamate could be used instead of sodium saccharin.

It would be apparent to those skilled in the art that further modifications of the examples illustrating the invention may be made.

3 «. /

Claims (16)

An astringent dentifrice containing: about 20-90% by weight of a liquid carrier, containing: water in an amount of at least about 3% by weight of said dentifrice, about 0.5-5% by weight of a gelling agent and about 10-50 wt% of a polishing agent comprising a synthetic precipitated amorphous silica gel having an average particle size of 1 to 30 microns and 2 a) a specific surface area of 1 to 600 m / g, b ) a pore volume of 0.05 to 0.5 cm "Vg, 2 c) a product of a specific surface (in m / g) x pore volume (in cm / g) of less than or equal to 240, d) a calculated pore diameter of 1.5 to 2.5 nm and e) a water content of less than 25% by weight, and with at most about 5% of a water-soluble zinc salt, which is at least about 50 ppm zinc ions provided to said dentifrice. The astringent dentifrice of claim 1, wherein said gelling agent is a gelling agent based on alkali metal carboxymethyl cellulose. The astringent dentifrice according to claim 1 or 2, 20 further comprising an alkali metal monofluorophosphate in an amount providing about 0.01-1% fluoride ions. The astringent dentifrice according to any one of claims 1, 2 or 3, wherein said zinc salt is present in an amount of 0.01-3% by weight. The astringent dentifrice according to any one of claims 1, 2 or 3, wherein said zinc salt is selected from the group consisting of zinc sulfate, zinc chloride, zinc bromide, zinc iodide, zinc nitrate and zinc acetate. The astringent dentifrice of claim 5, wherein said zinc salt is zinc sulfate heptahydrate. The astringent dentifrice according to claim 5, wherein said zinc salt is zinc chloride. »· * - ·% I—» * · 'V · * -. -Ir '-25- 5. 1 The astringent dentifrice according to claim 1, wherein said water in said liquid carrier constitutes about 3-10% by weight of said dentifrice and said synthetic amorphous silica gel constitutes about 10-40% by weight of said dentifrice . The astringent dentifrice according to claim 1, wherein said water in said liquid carrier constitutes about 11-50% by weight of said dentifrice. The astringent dentifrice of claim 1, wherein said synthetic amorphous silica gel is at least one of the synthetic amorphous silica gels having the following other characteristics: a b c Average particle size (according to Coulter) 4 474 The astringent gel-shaped dentifrice according to any one of claims 2, 4 or 5, wherein said gelling agent is sodium carboxymethyl cellulose. The astringent dentifrice according to any of claims 3, 4 or 5, wherein said alkali metal monofluorophosphate is sodium monofluorophosphate. The astringent dentifrice of claim 4, wherein said water-soluble zinc salt is present in an amount providing about 1000 ppm zinc ions and said alkali metal monofluorophosphate is present in an amount providing about 1000 ppm fluoride. *? -26- The astringent dentifrice of claim 13, wherein said zinc salt is zinc sulfate heptahydrate and said alkali metal monofluorophosphate sodium monofluorophosphate. 15. The astringent dentifrice according to any one of claims 1, 2 or 3, wherein said dentifrice is packaged in an internally uncoated aluminum tube. 15 Moist sieve residue (42 ^ im)% 0.02 0.02 0.02 pH (5% suspension in water) 3 6 6-8 2 Specific surface area (Ξ.Ξ.Τ.) m / g 7 4 7 Dry loss% 7 4 7 r 20 SiO content 2 · «(on glow material)% 96 99 96 Refractive index 1.46 1.46 1.46 The astringent dentifrice according to any one of claims 1, 2 or 3, wherein said dentifrice also contains about 0.005-0.5 wt% zinc oxide. J I ij