Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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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.
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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.
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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
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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
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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
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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
