CA1333885C

CA1333885C - Toothpaste

Info

Publication number: CA1333885C
Application number: CA000529477A
Authority: CA
Inventors: Helmut Harth
Original assignee: Blendax GmbH
Current assignee: Blendax GmbH
Priority date: 1986-03-07
Filing date: 1987-02-11
Publication date: 1995-01-10
Anticipated expiration: 2012-01-10
Also published as: EP0236827A3; DE3607480A1; DE3607480C2; GR3000731T3; JPS62212314A; EP0236827A2; ES2015546B3; EP0236827B1; DE3762799D1; ATE52910T1

Abstract

Toothpaste reducing the formation of dental calculus being substantially free from compounds releasing calcium ions contains as active ingredients a synergistic mixture of a di- and/or tetraalkali pyrophosphate and ethan-1-hydroxy-1,1-diphosphonic acid and/or water-soluble salts thereof and/or alkylene diaminotetra(methylene phosphonic acids) and/or water-soluble salts thereof.

Description

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Toothpaste 1 The present invention relates to a toothpaste having calculus-reducing properties.

Numerous active agents have already been proposed for the use in dental and oral hygiene products which shall reduce the formation of dental calculus.

In this respect, ethane-1-hydroxy-1,1-diphosphonic acid (EHDP) is one of the most intensively investigated substances. Its use ;n toothpastes was proposed for the first time in FR-A 1,514,194.

Meanwhile this proposal has also been used commercially; a toothpaste con-taining this active ingredient is on the market in several countries since a long period of time.

However, the calculus-reduction which can be achieved by such a toothpaste is below 30 %.

Apart from the numerous other complexing agents proposed for this purpose, alkylene diaminotetra(methylene phosphonic acids) and their salts may be used as calculus-inhibiting agen~ according to DE-A 2,255,177.

It is well-known that such calculus-reducing agents in toothpastes should only be used together with polishing agents which do not release calcium ions; this is already indicated in the above mentioned FR-A 1,514,194.

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1 Preferred abrasives in compositions containing such complexing agents are the different silica gels as for example proposed in DE-A 2,310,771.

Another group of substances showing calculus-reducing properties in vitro as well as in vivo are tetraalkali pyrophosphates, especially tetrasodium and tetrapotassium pyrophosphate; see W.W. Briner, M.D. Francis, Calc.
Tiss. Res. 11 (1973), 10 to 22.

Also the EP-A 97,476 makes use of the disclosure of this scientific publi-cation claiming oral hygiene products containing dialkali and/or tetra-alkali pyrophosphates.

o In clinical studies these toothpastes achieved an average reduction of the calculus formation from about 26 % to about 35 % (see J. Amer.
Dental Assoc. 110 (1985), 737 to 738, and J. Dental Res. 64 (1985), 1159 to 1162).

Thus, the reduction of the calculus formation which may be effected by the well-known, above mentioned toothpastes seems to be limited.

It has now been found, and this is the object of the present invention, that a significantly higher reduction of calculus formation may be achieved when using a toothpaste containing a mixture of at least one dialkali or tetraalkali pyrophosphate and at least one substance of the group ethane-1-hydroxy-1,1-diphosphonic acid and/or salts thereof and/or alkylene diamino-tetra (methylene phosphonic acids) and/or salts thereof as a calculus-in-hibiting ingredient.

It was surprising and could not be foreseen that such an improvement of the effect would be attained by combination of these active ingredients, as on the one hand it is well-known that an increased concentration of the single active agents does not lead to a proportional increase of activity and moreover can be harmful for the dental enamel as it may possibly hamper its remineralization, on the other hand up to now no improvement of the activity could be observed when using different combinations of well-known complexing components.

Thus, a real inventive selection among the numerous possibilities which are available was necessary to find out the mixture according to the invention showing a surprisingly synergistic effect in inhibition of dental calculus formation.

5 This effect has been proven in rat experiments.

The percentage of ethane-1-hydroxy-1,1-diphosphonic acid in the toothpaste according to the invention is preferably about 0,2 to 2,0 % by weight, especially between about 0,5 and 1,0 % by weight, calculated to the total composition.

0 If the salts, e.g. the di- and trisodium salt of EHDP, are used, this per- centage refers to the proportion of free acid.

If alkylene diaminotetra (methylene phosphonic acids) or their salts, pre-ferably C2-C8-alkylene diaminotetra (methylene phosphonic acids),are used, their percentage is between about 0,5 and 5,0, preferably between 1 15 and 3, especially at about 1,5 % by weight, calculated to the acid and the total toothpaste composition.
The tetrasodium salts are preferred.
Especially suitable components are ethylene and hexamethylene diamino-tetra (methylene phosphonic acid) and their salts.

20 Suitable alkali pyrophosphates are especially disodium and dipotassium as well as tetrasodium and tetrapotassium pyrophosphate.
The percentage of these compounds in the toothpaste according to the invention is between about 1 and about 5 % by weight, preferably between 2 and 4, especially from about 2,5 and 3,5 % by weight, calculated to the 25 total composition of the toothpaste, in each case also calculated to the pyrophosphate ion.

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1 As already mentioned, the toothpastes according to the invention should not contain any abrasive which is able to release a substantial amount of cal-clum ions.

Therefore suitable abrasives are especially silica gels like precipitated silica gels, silica xerogels and hydrogels, alkalialuminum silicates, e.g.
those of the Zeolith type like synthetic sodium aluminum silicate of the empiric formula Na12(A102)12(SiO2)12. 27H20, aluminum oxide and aluminum oxide trihydrate, insoluble metaphosphates, pulverized synthetic plastic materials as well as heat treated calcium pyrophosphate.

o Of course, polishing agent mixtures of different abrasives may also be used, e.g. a mixture of a-aluminumoxide trihydrate and/or insoluble alkali metaphosphate and synthetic Zeolith A in the ratio of approx. 1:1.

The abrasive percentage in the toothpastes according to the invention is preferably between about 20 and 60 % by weight, calculated to the total composition.

Usually, surface-active agents are used in toothpastes up to a percentage of about 2,5 % by weight, calculated to the total composition.

Such synthetic surface-active substances are for example alkyl sulphates, alkyl ether sulphates, olefin sulfonates, sodium lauroyl sarcosinate, and ampholytic, non-ionic or cationic compounds or also soaps like such of lauric acid, myristic acid, palmitic acid, stearic acid, or mixtures thereof, for example coconut oil acids or tallow fatty acids.

The same relates to the moisturizers normally used in toothpastes in quan-tities between about 10 and about 35 % by weight, like glycerol, diols, e.g. 1,4-butanediol or 1,2-propanediol, or sugar alcohols like sorbitol, mannitol or xylitol, and polyglycols with low molecular weights, as well as to thickening agents, which are present in toothpastes from about 0,25 and about 2,5 % by weight, calculated to the total composition.

Preferred thickening agents are carboxymethyl cellulose and its alkali salts, especially sodium carboxymethyl cellulose, hydroxyalkyl celluloses like hydroxymethyl cellulose and hydroxyethyl cellulose, methyl cellulose, 0 gums like gum tragacanth, arabic gum, Caraya gum, Guar gum, Xanthan gum and Irish Moss, synthetic polyelectrolytes like the amine and alkali salts of polyacrylic acid as well as inorganic thickening agents, e.g. colloidal magnesium aluminum silicate or colloidal silica.

Of course also other active ingredients can be used in the toothpastes according to the invention.

Such ingredients are especially the well-known caries-prophylactic fluorides, preferably in such a quantity that the concentration of pure F
ion in the toothpaste is between 0,05 and about 1 % by weight, preferably 0,1 to 0,5 % by weight, of the toothpaste.

20 Suitable fluorine compounds are especially the different salts of mono-fluorophosphoric acid like sodium, potassium, lithium, calcium and aluminum mono- and difluorophosphate as well as different fluorides, especially alkali fluorides like sodium, lithium, potassium and ammonium fluoride, stannous fluoride, manganese fluoride, copper fluoride, zirconium fluoride, 25 and aluminum fluoride. Also mixtures or addition products of these fluorides with other fluorides may be used, e.g. alkali manganese fluoride.

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Further ingredients which may be used in the toothpastes according to the invention are agents which inhibit dental plaque formation like chlor-hexidine salts, zinc and copper compounds, urea, hexetidine, hesperidine, allantoin, azulene, etc..

5 The pH value of the toothpaste according to the invention is between about 4 and about 10, preferably 5,5 and 9,5.

A survey on the compositions to be used in toothpastes, as well as of the substances which are usually used for the manufacture of dental care pro-ducts and the manufacturing processes applied, is given in the monography o of M.S. Balsam and E. Sagarin, "Cosmetics - Science and Technology", 2nd Ed., Vol. 1, p. 423 to 533 (1972), which is included by reference.

The following examples characterize the nature of the present invention:

Example 1 c~-aluminumoxide trihydrate 38,00 (% by weight) Sorbitol 10,00 Glycerol 5,00 Methyl cellulose 0,80 Hydroxyethyl cellulose 0,40 Sodium monofluorophosphate 0,76 Sodium fluoride 0,11 Sodium lauryl sulphate 1,20 Flavour mixture 1,00 Saccharin sodium 0,08 Colloidal silica 3,50 Methyl p-hydroxybenzoate, sodium salt 0,25 EHDP, trisodium salt 0,85 Tetrasodium pyrophosphate 3,75 Allantoin 0,25 Water ad 100,00 -~ 1333885 1 ExamPle 2 Precipitated silica gel 23,50 (% by weight) Silica aerogel 2,50 Glycerol g,oo Sorbitol 17,50 Sodium lauryl sulphate 1,50 Carboxymethyl cellulose 1,25 Sodium fluoride 0,25 Flavour mixture 1,10 Saccharin sodium 0,05 Copper sulphate . 5 H20 0,25 Hexetidine 0,05 Methyl p-hydroxybenzoate, sodium salt 0,20 n-Propyl p-hydroxybenzoate, sodium salt 0,10 Hexamethylene diaminotetra(methylene phosphonic acid), tetrasodium salt 1,30 Tetrapotassium pyrophospate 3,10 Water ad 100,00 Example 3 Insoluble sodium metaphosphate 38,00 (% by weight) Sorbitol 13,00 Colloidal silica 2,80 Hydroxyethyl cellulose 1,80 Methyl p-hydroxybenzoate 0,10 Benzoic acid 0,10 Saccharin sodium 0,20 Flavour mixture 1,10 Fatty alcohol polyglycolether 0,60 1,2-Propan~diol 4,00 Titanium dioxide 0,80 N,N',N'-Tri(2-hydroxyethyl) N-octadecyl 1,3-diaminopropane dihydrofluoride 2,00 Disodium pyrophosphate 2,80 Tetrapotassium pyrophosphate 1,20 EHDP, disodium salt 0,60 Water ad 100,00 l Example 4 Polymethyl methacrylate powder 15,00 (% by weight) (average particle size 1-5,um) Heat-treated ~ -calciumpyrophosphate 15,00 Sodium carboxymethyl cellulose 1,20 Sodium lauroyl sarcosinate 0,80 Sodium lauryl sulphate 0,80 Sodium monofluorophosphate 1,20 Saccharin sodium 0,10 o Flavour mixture 1,10 Ethylene diaminotetra(methylene phosphonic acid), 1,80 tetrasodium salt Tetrasodium pyrophospate 3,20 EHDP, disodium salt 0,30 Glycerol 10,00 Sorbitol 8,00 Water ad 100,00 Example 5 Silica xerogel 25,00 (% by weight) Silica aerogel 2,80 Sorbitol 35,00 Xanthum Gum 1,10 Sodium fluoride 0,30 EHDP, disodium salt 0,80 Disodium pyrophospate 1,00 Tetrasodium pyrophosphate 1,80 Tetrapotassium pyrophosphate 1,00 Sodium lauryl sulphate 1,30 Sodium lauroyl sarcosinate 0,80 Flavour mixture 1,00 Saccharin sodium 0,10 Methyl p-hydroxybenzoate, sodium salt0,30 Dyestuff q.s.
Water ad 100,00 g 1 Example 6 Calcined calcium pyrophosphate45,00 (% by weight) Insoluble sodium metaphosphate 51 Glycerol 5,50 Sorbitol 12,50 Sodium carboxymethyl cellulose 1,20 Sodium sulforicinoleate 0,80 Sodium lauryl sulphate 1,20 Ethylene diaminotetra(methylene phosphonic acid), lo tetrasodium salt 2,50 Tetrasodium pyrophospate 2,00 Disodium pyrophosphate 1,20 Sodium monofluorophosphate 1,14 Saccharin sodium 0, 11 Flavour mixture 1,00 Sodium benzoate 0,30 Methyl p-hydroxybenzoate, sodium salt 0,15 Water ad 100,00

Claims

1. Toothpaste reducing the formation of dental calculus, being substantially free from compounds releasing calcium ions, comprising mixtures of:
(a) dialkali pyrophosphate or tetraalkali pyrophosphate or mixtures thereof; and (b) at least one compound selected from the group consistingly of ethan-1-hydroxy-1, 1-diphosphonic acid, water-soluable salts of ethan-1-hydroxy-1, 1-diphosphonic acid, alkylene diaminotetra (methylene phosphonic acids), water-soluable salts of alkylene diaminotetra (methylene phosphonic acids), and mixtures thereof.

2. The toothpaste according to claim 1 wherein dialkali pyrophosphate or tetraalkai pyrophosphate or mixtures thereof comprises 1 to 5% by weight of the toothpaste, calculated to the free phosphonic acid.

3. The toothpaste according to claim 1 wherein said ethan-1-hydroxy-1, 1-diphosphonic acid or water-soluable salts of ethan-1-hydroxy-1, 1-diphosphonic acid or mixtures thereof comprises 0.2% to 2.0% by weight of the toothpaste, calculated to free phosphonic acid.

4. The toothpaste according to claim 2 wherein said ethan-1-hydroxy-1, l-diphosphonic acid or water-soluable salts of ethan-1-hydroxy-1, 1-diphosphonic acid or mixtures thereof comprises 0.2% to 2.0% by weight of the toothpaste, calculated to free phosphonic acid.

5. The toothpaste according to claim 1, 2, 3 or 4 wherein said alkylene diaminotetra (methylene phosphonic acids) or water-soluable salts of alkylene diaminotetra (methylene phosphonic acids) or mixtures thereof comprises 0.5% to 5.0% by weight of the toothpaste, calculated to free phosphonic acid.