CH660960A5 - TOOTHPASTE. - Google Patents

Description

The invention encompasses toothpastes which contain 20 to 80% by weight of the toothpaste in a liquid carrier composed of water and one or more humectants and 0.5 to 5% by weight of the toothpaste in a gel-forming agent which is the hydroxyethyl cellulose defined above.

The toothpastes according to the invention can also contain a compound which provides at least 100 ppm of fluorine.

The toothpaste according to the invention is now characterized in that it contains 20 to 75% by weight of a polishing agent, at least about half of which consists of hydrated aluminum oxide, furthermore 20 to 80% by weight of a liquid carrier composed of water and one or more humectants and 0 , 5 to 5% by weight of a gel-forming agent consisting essentially of hydroxyethyl cellulose, whose with a Brookfield viscometer, spindle no. 6 at 20 rpm on a 2% by weight water: glycerol (1: 1.56) solution at 20 ° C measured viscosity is in a range whose average is at least 24,000 10 ~ 3 Pa.s.

Preferred toothpastes according to the invention can furthermore contain a compound which provides at least 100 ppm of fluorine.

The rheological advantages achieved in the toothpaste according to the invention are particularly evident when a preferred toothpaste contains a compound which provides at least 100 ppm of fluorine, typically 100 to 10,000 ppm and in particular 750 to 2000 ppm of fluorine. These connections include e.g. Sodium fluoride, tin (II) fluoride, potassium fluoride, potassium tin (II) fluoride, sodium hexafluorostannate, tin (II) chlorofluoride and sodium monofluorophosphate. Sodium monofluorophosphate or a mixture of sodium monofluorophosphate and sodium fluoride is particularly typical of the toothpaste according to the invention.

The toothpaste can typically contain sodium monofluorophosphate or a mixture of sodium monofluorophosphate and sodium fluoride in an amount

that 100 to 10,000 ppm fluorine, e.g. 750 to 2000 ppm and in particular 1400 to 2000, such as 1400 to 1670 ppm fluorine are provided. A binary fluorine-providing system of sodium monofluorophosphate and sodium fluoride is advantageously used, in which 30 to 40% by weight of the fluorine, e.g. 30 to 35%. i.e. 300 to 580 ppm of sodium fluoride can be supplied.

5 sodium monofluorophosphate. Well; POiF. that is commercially available can vary considerably in purity. It can be used in any suitable purity provided the contaminants do not significantly affect the properties desired.

In general, the purity is desirably at least 80%. For best results, it should be at least 85% and preferably at least 90% by weight sodium monofluorophosphate, with the remainder consisting primarily of manufacturing contaminants or by-products such as sodium fluoride and water-soluble sodium phosphate salt. In other words, the sodium monofluorophosphate used should have a total fluoride content of over 12%, preferably over 12.7%. have a content of not more than 1.5% 20 and preferably not more than 1.2% free sodium fluoride and a sodium monofluorophosphate content of at least 12%, preferably at least 12.1%, all calculated as fluoride.

As indicated above, in the preferred binary system, sodium fluoride is a fluorine-containing component that can be separate from sodium monofluorophosphate. 300 to 580 ppm of fluorine is preferably supplied to the toothpaste by sodium fluoride.

The gel-forming agent is contained in a preferred toothpaste according to the invention in an amount of 0.8 to 2% by weight and in particular 0.9 to 1.4% by weight. A typical hydroxyethyl cellulose which is effective for the toothpaste according to the invention is Tylose H 10000P from Farbwerke Hoechst, Frankfurt / Main, West Germany. 35 The gel-forming agent is contained in the toothpaste according to the invention in an amount of 0.5 to 5% by weight, preferably 0.8 to 2% by weight and in particular 0.9 to 1.1% by weight. Tylose H 10000P is a typical hydroxyethyl-40 cellulose which is effective for the toothpaste according to the invention.

Tylose H 10000P and other hydroxyethyl celluloses which can be used in the toothpaste according to the invention have viscosities in a range whose average is at least 24 000 10 -3 Pa.s, measured with a Brookfield 45 viscometer at 20 C on a water: glycerol (1: 1.56 ) Solution with a No. 6 spindle at 20 rpm. High viscosity hydroxyethyl celluloses which can be used in the toothpaste according to the invention are listed in the table below.

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table

Manufacturer

HEC

Viscosity in 10 3 Pa.s

55 Hercules Hercules Hoechst

60

Natrosol 250 HR

and 250 H Natrosol 250 HHR

and 250 HH Tylose H 10000 P

17,000-31,000

37,000-41,000 20,000-30,000.

Hydroxyethyl celluloses with a viscosity, the average of which does not reach 24 000 10 "3 Pa.s, such as Hercules 250 M and MR (average viscosity 15 500 10 ~ 3 65 Pa.s) and Tylose H 4000P from Hoechst (viscosity up to 23 000 10 "3 Pa.s) do not lead to the desired rheological properties if they are used as the only gelling agent.

660 960

4th

If the toothpaste contains 20 to 75% by weight of a polishing agent, at least about half of which consists of hydrated aluminum oxide, if desired, up to about half of the total polishing agent can consist of a further dentically acceptable polishing agent, such as silicon cium dioxide, dicalcium phosphate, calcined aluminum oxide, zirconium silicate, insoluble sodium methaphosphate and others Preferably 40 to 55% by weight of polishing agent, which typically consists entirely of hydrated alumina, is present.

The hydrated alumina used preferably has a small particle size, i.e. at least 85% by weight of the particles are smaller than 20 µm, such as that classified as gibbsite (a-alumina trihydrate), which is normally defined as Al203 * 3H20 or Al (OH) 3.

The alpha alumina trihydrate can have a particle size in the range of about 2.6 to 10 µm. The a-alumina trihydrate sold by Alcoa as C333 consists of fine-particle gibbsite and is particularly desirable. The average particle size of C333 alumina is about 7 to 9 µm (Coulter counter). It can be obtained by finely grinding the alumina trihydrate sold by Alcoa as C333. Other hydrated aluminum oxides that can be used are AF 260 and AF 230 from the British Aluminum Company and SH 100 from Rhone-Poulenc.

The toothpaste containing hydrated alumina is usually filled into containers from which it can be easily expressed, e.g. from a pressure differential or mechanically operated dispenser or from a lined or non-lined aluminum or lead tube or a laminate tube. The rheological properties are particularly desirable when using a mechanical dispenser of the type described in British Patent Application 2,070,695, which was published on September 9, 1981 and which is incorporated herein by reference. This dispenser has a mouthpiece, a pull rod, a piston and a manual control. Dispensers that are operated by pressure differential can be of the aerosol or vacuum type.

The hydrated alumina-containing toothpaste may contain a fluoride-providing compound or a binary fluorine-providing system as described above.

In toothpaste formulations, the carrier consists of a liquid phase, which is generally mixed with gel-forming agents in such quantities that an expressible creamy mass of the desired consistency is produced. In general, the liquids in the toothpaste mainly contain water, glycerin, sorbitol, polyethylene glycol 400, propylene glycol or the like, including suitable mixtures of these components. Usually it is advantageous to use a mixture of water and a humectant or binder such as glycerin or sorbitol. Typically, about 10 to 30 weight percent water and about 15 to 50 weight percent humectant are used. Glycerol or sorbitol is preferably used. The total liquid content is generally about 20 to 80% by weight of the formulation.

Any suitable surface-active agent or surfactant can be incorporated into the toothpaste formulations. Such compatible materials are desired in order to impart further cleaning, foaming and antibacterial properties to the toothpaste, depending on the specific type of the surfactant selected for this. These surfactants are usually water soluble and can be anionic, nonionic or cationic. Water-soluble synthetic organic surfactants that are not soaps are normally preferred. Suitable surfactants are known and include e.g. the water soluble salts of higher fatty acid monoglyceride monosulfates, e.g. Sodium coconut fatty acid monoglyceride monosulfate, higher alkyl sulfates, e.g. Sodium lauryl sulfate, alkylaryl sulfonates, e.g. Sodium dode-cylbenzenesulfonate, higher fatty acid esters of 1,2-dihydroxy propane sulfonate and the like.

Further preferred surface-active agents are the substantially saturated higher aliphatic acylamides of lower aliphatic aminocarboxylic acid compounds, e.g. those with 12 to 16 carbon atoms in the acyl radical. The amino acid content generally comes from lower aliphatic saturated monoaminocarboxylic acids having about 2 to 6 carbon atoms, usually the monocarboxylic acids. Suitable compounds are the fatty acid amides of glycine, sarcosine, alanine, 3-aminopropanoic acid and valine with about 12 to 16 carbon atoms in the acyl radical. Preferred are the N-lauroyl, myristoyl and palmitoyl sarcoside compounds with which optimal effects are achieved.

The preferred amide compound can be used in the form of the free acid or, preferably, as a water-soluble salt, e.g. as an alkali metal, ammonium, amine or alkylolamine salt. Specific examples are the sodium and potassium N-lauroyl, myristoyl and palmitoyl sarcosides, ammonium and ethanolamine N-lauroyl glycide and alanide. The term “aminocarboxylic acid compound”, “sarcoside” and the like here denotes compounds with a free carboxyl group or their water-soluble salts.

These materials can be used in pure or substantially pure form. As far as possible, they should be free of soap or similar higher fatty acid materials that reduce the effectiveness of these compounds. In practice, the amount of the higher fatty acid materials is usually less than 15% by weight of the amide and is not sufficient to adversely affect it, and preferably the amount is less than about 10% of the amide material.

Various other materials can be incorporated into the toothpastes according to the invention. Examples of these are coloring or whitening substances, preservatives, stabilizers, tetrasodium pyrophosphate, silicones, chlorophyll compounds and ammoniated materials such as urea, diammonium phosphate and mixtures thereof. These auxiliaries are generally incorporated in amounts such that they do not significantly impair the desired properties of the toothpaste and are expediently selected and used in conventional amounts.

For some purposes it may be desirable to incorporate antibacterial agents into the formulations according to the invention. Typical antibacterial agents that can be used in amounts of from about 0.01 to about 5%, preferably from about 0.05 to about 1.0%, by weight of the dentifrice are:

N1 -4-chlorobenzyl) -N5- (2,4-dichlorobenzyl) biguanide;

p-chlorophenyl biguanide;

4-chlorobenzylhydryl biguanide;

4-chlorobenzylhydrylguanyl urea; N-3-lauroxypropyl-N5-p-chlorobenzyl biguanide; 1,6-di-p-chlorophenyl biguanide hexane; l- (lauryldimethylammonium) -8- (p-chlorobenzyldimethyl-

ammonium) octane dichloride; 5,6-dichloro-2-guanidinobenzimidazole; N'-p-chlorophenyl-N5 laury ibiguanide;

5-amino-1,3-bis (ethylhexyl) -5-methylhexahydro-

pyrimidine;

and their non-toxic acid addition salts.

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660 960

Flavoring can be imparted to the compositions according to the invention with any suitable flavoring or sweetening agent. Examples of flavor components are flavoring oils, e.g. the oils of spearmint, peppermint, wintergreen, sassafras, clove, sage, eucalyptus, marjoram, cinnamon, lemon and orange oil, as well as methyl salicylate. Suitable sweeteners include sucrose, lactose, maltose, sorbitol, sodium cyclamate, sodium saccharin dipeptides according to US Pat. No. 3,939,261 and oxathiazine salts according to US Pat. No. 3,932,606. The amount of flavoring and sweetening agents together is suitably about 0. 01 to 0.5% or more of the formulation.

The toothpastes should have a practical pH for the application. If the polishing agent consists of hydrated aluminum oxide, the pH can be 3 to 10.5. These pH values should be understood to mean that they were measured directly on the toothpastes. If desired, generally 4 to 7.5 substances, such as benzoic acid or citric acid, can be added to adjust the pH.

The toothpaste is usually placed in a squeezable tube, e.g. made of lined or not lined aluminum or lead, or in general in laminated tubes and in particular if the toothpaste contains hydrated aluminum oxide, filled into mechanically operated dispensers.

The following example illustrates the invention. All quantities are based on weight, unless otherwise stated.

example

Highly viscous hydroxyethyl cellulose hydrated aluminum oxide - no fluoride and no binary fluorine sources

The following toothpastes are made in the usual way. The toothpastes A and B are filled into mechanically operated dispensers according to British patent application 2 070 695A. The toothpaste C is filled into a non-lined aluminum tube and the toothpaste D into a lined aluminum tube.

A

Parts

B

C.

D

Sorbitol, 70% solution

23.00

23.00

-

23.00

Glycerin

-

-

20.20

-

Hydroxyethyl cellulose

(Hercules Natrosol 250 M)

-

1.00

-

-

Hydroxyethyl cellulose

(Hoechst Tylose H 10000 P)

1.00

-

1.30

1.00

a-alumina trihydrate

(Alcoa C333)

52.00

52.00

52.00

52.00

Ci 2-C! 8-alcohol sodium

sulfate (100% AI)

0.5

0.5

1.5

1.5

Zinc sulfate .7H20

-

-

0.48

-

Aluminum sulfate, 18H20

-

-

-

0.78

Sodium saccharin

0.17

0.17

0.20

0.17

Methyl p-hydroxybenzoate

0.08

0.08

0.08

-

Sodium monofluor

phosphate

0.76

0.76

-

-

Sodium fluoride

0.10

0.10

-

-

Pyridylcarbinol

0.10

0.10

-

-

Allantoin

0.15

0.15

0.15

-

Flavoring

1.20

1.20

1.00

1.20

Phosphoric acid, 85%

0.14

0.14

-

-

deionized water

to fill up

100

100

100

100

30th

During filling and pressing, the surfaces of toothpastes A, C and D are smooth and theologically desirable, while toothpaste B flows out of the container during filling and pressing. Similar rheo-35 logic properties as toothpastes A, C and D are achieved if the Tylose H 100 OOP in these toothpastes is replaced by Natrosol 250 H and Natrosol 250 HH. Tail formation occurs when toothpaste B (with Natrosol 250 M) is filled into a tube.

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Claims (9)

660 960 2nd PATENT CLAIMS 1. Toothpaste, characterized in that it contains 20 to 75% by weight of a polishing agent, at least about half of which consists of hydrated aluminum oxide, further 20 to 80% by weight of a liquid carrier composed of water and one or more humectants and 0, 5 to 5% by weight of a yellowing agent which consists essentially of hydroxyethyl cellulose, whose with a Brookfield viscometer, spindle no. 6 at 20 rpm on a 2% by weight water: glycerol (1: 1.56) solution at 20 ° C. measured viscosity is in a range, the average of which is at least 24,000 10 "3 Pa.s. 2. Toothpaste according to claim 1, characterized in that it contains 40 to 55% by weight of a-alumina trihydrate as a polishing agent. 3. Toothpaste according to claim 1 and 2, characterized in that it is filled into a dispenser operated by a pressure differential, a mechanically operated dispenser or in a tube. 4. toothpaste according to claims 1 to 3, characterized in that a fluorine-providing compound is present in an amount which provides 100 to 10,000 ppm of fluorine. 5. toothpaste according to claim 4, characterized in that the fluorine of sodium monofluorophosphate is provided in an amount of 750 to 2000 ppm. 6. Toothpaste according to claim 4, characterized in that 750 to 2000 ppm fluorine are provided by a binary fluorine system consisting of sodium monofluorophosphate and sodium fluoride, 30 to 40% by weight of the fluorine being supplied by sodium fluoride. 7. toothpaste according to claims 1 to 4 and 6, characterized in that it contains zinc sulfate or aluminum sulfate in an amount of 0.05 to 1.5 wt.%. 8. Toothpaste according to claims 1 to 7, characterized in that the hydroxyethyl cellulose has a viscosity of 17,000 to 31,000 10 ~ 3 Pa.s, from 37,000 to 41,000 10 ~ 3 Pa.s or from 20,000 to 30,000 Has 10-3 Pa.s. 9. toothpaste according to claims 1 to 8, characterized in that it contains the gel-forming agent in an amount of 0.8 to 2 wt.%. In toothpastes, sodium carboxymethyl cellulose is commonly used as the gel-forming agent of choice because of its ready availability and the generally satisfactory rheological properties it imparts to toothpastes, particularly when the toothpaste is made and used in moderate climates. In tropical climates, cellulose can decompose. Toothpaste made with many grades of sodium carboxymethylcellulose is observed even at room temperature, especially when subjected to dynamic aging, i.e. if you squeeze them out of a tube twice a day for 2 weeks over a period of 2 weeks, which corresponds to the normal use of a toothpaste, that the toothpastes get a rough appearance, i.e. form soft lumps. Even quality grades of sodium carboxymethyl cellulose, which do not cause a rough appearance during dynamic aging, can lead to other rheological problems, e.g. B. received, «standing properties», so that the expressed toothpaste quickly settles to a flat band or thickens over time. It should be noted. that a rough appearance occurs during dynamic aging, especially if the toothpaste contains a fluoride-providing compound and a calcium phosphate as a polishing agent. Minor problems arise when the fluorine is supplied from sodium monofluorophosphate or a mixture of sodium monofluorophosphate and sodium fluoride and the polishing agent is a silicic acid material. However, the problem is readily apparent when the fluorine from sodium monofluorophosphate or a mixture of sodium monofluorophosphate and sodium fluoride in a minimum of about 35% by weight calcium phosphate, such as dicalcium phosphate as a polishing agent, is provided to the toothpaste. Attempts to overcome the problem of roughening without causing other problems, such as poor «standing properties», consisted in mixing different grades of sodium carboxymethyl cellulose or in mixing sodium carboxymethyl cellulose with other gelling agents, such as synthetic inorganic siliceous clays, e.g. B. of materials that are available under the trademarks "Laponite" and "Veegum", thickeners, such as silicic acid thickeners from Hu-25ber under the trademark "Zeosyl", such as Zeosyl 200, Tixo-sil, such as Tixosil 33J from Rhone -Poulenc or the "HDK N20" product from Wacker and liquid materials such as polyethylene glycol 600. These attempts were unsatisfactory. 30 Hydroxyethyl cellulose has been suggested as an alternative gelling agent to sodium carboxymethyl cellulose, and indeed hydroxyethyl celluloses, such as Natro-sol M, have been used in commercially available toothpastes. Different quality grades of hydroxyethyl cellulose are 35 e.g. in U.S. Patents 3,862,307 (Natrosol G) and 3,070,510 (Brookfield viscosity at 20 ° C 75 to 125 10 -3 Pa.s; 2% in water) and 4,022,881 (Natrosol 250 H, a highly viscous material ) described. Although these hydroxyethyl celluloses are generally satisfactory, they can lead to expansion rheology in toothpastes through visible “tailing” when filling into containers and when pressed onto a toothbrush. For example, "Viscous Fluid" is described in U.S. Patent 4,022,881 for toothpastes containing a mixture of 30% hydroxyethyl cellulose and 70% sodium carboxymethyl cellulose as a thickening agent. A non-tough toothpaste with calcium carbonate as an abrasive and a mixture of 10% hydroxyethyl cellulose and 90% sodium carboxymethyl cellulose as a thickener is also described there. In the toothpaste according to the invention, a gel-forming agent is provided which has little tendency to have a rough appearance with aging and has other desired rheological properties, such as good "stand", no "tail formation" when a band of toothpaste is expressed and good ones Shine of this ribbon. The toothpaste can be easily produced with this agent, without having to make significant 60 modifications to the manufacturing process compared to the manufacture with sodium carboxymethyl cellulose as the only gel-forming agent. This gel-forming material is hydroxyethyl cellulose, whose viscosity measured with a Brookfield viscometer, spindle no. 6 at 20 rpm on a 2% strength water: glycerol (1: 1.56) solution at 20 ° C. lies in a range whose average is at least 65 24,000 is 10-3 Pa.s. In the above-mentioned U.S. Patent 4,022,881 a dentifrice is described which, as a thickener, contains 5 to 30% of highly viscous hydroxyethyl cellulose, e.g. Natrosol 3rd 660 9öü Contains 250 H and 70 to 95% sodium carboxymethyl cellulose to stabilize the sodium carboxymethyl cellulose against degradation. These ratios of e.g. 10: 1 and 7: 3 are not satisfactory because, unlike the invention, they do not remove the surface roughness. According to the invention there is provided a gel-forming agent for a toothpaste which remains smooth during dynamic aging and has other generally desired theological properties. A particular advantage of the toothpaste according to the invention is that it does not flow away and has an improved stand, even if the hydroxyethyl cellulose predominates in the gel-forming system. This advantage can be particularly noticeable when the toothpaste is filled or expressed from a pressure differential or mechanically operated container or tube, especially when using hydrated aluminum oxide as a polishing agent. The claimed advantages can be achieved with hydroxyethyl cellulose, which is highly viscous, without the addition of sodium carboxymethyl cellulose. Further advantages are evident in preferred toothpastes which preferably contain a source of fluorine, e.g. a binary fluorine-producing system of sodium monofluorophosphate and sodium fluoride.