Note: Descriptions are shown in the official language in which they were submitted.
21~0370
WO 9~01080 PCT/EP93/01701
Liquid tooth-cleaning formulations
This invention relates to liquid tooth-cleaning
formulations which show long-term fluidity.
Toothpastes normally exhibit pseudoplastic behavior
and can be characterized by their yield point. They may
be extruded from a tube and assume a stable position on
the toothbrush. However, this formulation requires some
care on the part of the user during extrusion because the
toothpaste can emerge suddenly from the tube. In such an
event, part of the strand of toothpaste often drops off
on application to the toothbrush or on insertion of the
toothbrush into the mouth and remains unused in the oral
cavity or in the wash basin.
The problem addressed by the present invention was
to provide a liquid tooth-cleaning formulation showing
long-term fluidity. In the context of the invention,
long-term fluidity means that the tooth-cleaning formula-
tion is present in liquid form and, depending on the
viscosity to which it is adjusted, issues thinly from a
storage container or can be removed dropwise from a
container and that the consistency established is retain-
ed for a prolonged period until the formulation has been
used up. The tooth-cleaning formulation according to the
invention would penetrate between the bristle heads
immediately on application to the toothbrush and not
after a few brushing movements, as is the case with
conventional toothpastes. After application, the liquid
tooth-cleaning formulation would remain on and between
the bristles pending use and would not run down the
bristle shafts. A liquid tooth-cleaning formulation such
as this would lend itself to exact dispensing and hence
to very economic use. There would be no need for direct
contact between the storage container and the brush in
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contrast to toothpastes extruded from a tube. This would
provide for particularly hygienic application. In
addition, a liquid tooth-cleaning formulation would
enable the storage container to be completely emptied
5 which is not possible with tubes of toothpaste.
The fact that the tooth-cleaning formulation would
be present in liquid form would not of course affect the
actual tooth-cleaning and dental-care properties of the
formulation.
It is known from DE-A5 16 67 871 that the hydrocol-
loid, xanthan, can be used as a suspending and thickening
agent in liquid dental-care formulations.
However, it has been found that the need for long-
term fluidity is not satisfied when xanthan is used in
15 the presence of silica abrasives. Thus, the fluidity of
a liquid dental-care formulation of the type in question
diminishes after a short time through the development of
excessive yield points and dynamic viscosities.
It has now surprisingly been found that a liquid
20 tooth-cleaning formulation retains its fluidity in the
long term providing xanthan is used in conjunction with
certain viscosity stabilizers as a consistency regulator.
In the context of the invention, the viscosity stabili-
zers in question are substances which prevent gradual
25 "after-thickening" of the liquid tooth-cleaning formula-
tion, i.e. the development of a high yield point.
The viscosity stabilizers according to the invention
are:
30 a) hydroxypropyl-substituted hydrocolloids or
b) cationic nitrogen-containing surfactants or
c) ampholytic surfactants or
d) N-acyl sarcosinates or
e) N-acyl taurides or
35 f) polyethylene glycol/polypropylene glycol copolymers
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WO 94/01080 3 PCT/EP93/01701
with an average molecular weight of 1,000 to 5,000.
Accordingly, the present invention relates to water-
and humectant-containing tooth-cleaning formulations in
the form of a liquid preparation with long-term fluidity
and a viscosity of 2,000 to 10,000 and preferably 5,000
to 8,000 mPa-s at 25C, xanthan in a quantity of 0.02 to
3.0% by weight being present as consistency regulator and
a compound selected from the group consisting of
a) hydroxypropyl-substituted hydrocolloids or
b) cationic nitrogen-containing surfactants or
c) ampholytic surfactants or
d) N-acyl sarcosinates or
e) N-acyl taurides or
f) polyethylene glycol/polypropylene glycol copolymers
with an average molecular weight of 1,000 to 5,000
in a quantity of 0.01 to 5.0% by weight or a combination
of the compounds mentioned under a) to f) in a quantity
of 0.01 to 10% by weight being present as viscosity
stabilizer (all the percentages by weight mentioned being
based on the tooth-cleaning formulation as a whole).
Xanthan is preferably present in a quantity of 0.01
to 0.8% by weight, based on the tooth-cleaning formula-
tion as a whole.
Hydroxypropyl-substituted hydrocolloids are prefer-
ably present in a quantity of 0.01 to 0.5% by weight,
based on the tooth-cleaning formulation as a whole. Pre-
ferred representatives are hydroxypropyl guar, hydroxy-
propyl cellulose, alginic acid propylene glycol esters or
carboxyethyl and carboxymethyl cellulose propylene glycol
esters. Accordingly, the propylene glycol function may
be attached both by an ether group and by an ester group.
The degree of etherification or esterification per hydro-
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WO 94/01080 4 PCT/EP93/01701
colloid monomer unit is in the usual range of 0.25 toabout 1.
Hydroxypropyl guar and alginic acid propylene glycol
ester are particularly preferred, being present in a
quantity of 0.01 to 0.5% by weight, based on the tooth-
cleaning formulation as a whole.
The ratio by weight of xanthan to hydroxypropyl-
substituted hydrocolloid is from 20:1 to 2:1 and prefer-
ably from 9:1 to 3:1.
Cationic nitrogen-containing surfactants are, for
example, quaternary ammonium compounds, for example cetyl
trimethylammonium chloride, dicetyl dimethylammonium
chloride or distearyl dimethylammonium chloride.
Ampholytic surfactants are, for example, betaines
corresponding to the following general formula:
RlN(CH3)2CH2COO
where R1 is, for example, lauryl, myristyl, cetyl,
stearyl, cocoalkyl, tallow alkyl or hydrogenated tallow
alkyl,
betaines corresponding to the following general formula:
+
R2c(o)NH(cH2)nN(cH3)2cH2coo
where R2, for example, may have all the meanings mentioned
for Rl and n is an integer of 1 to 6, for example laur-
amidopropyl dimethyl betaine or cocoamidopropyl dimethyl
betaine.
The betaines are preferably present in a quantity of
0.01 to 1.5% by weight, based on the tooth-cleaning
formulation as a whole. Lauramidopropyl betaine and
cocoamidopropyl betaine are particularly preferred. N-
acyl sarcosinates and N-acyl taurides are also viscosity
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WO 94/01080 5 PCT/EP93/01701
stabilizers in the context of the invention.
In the N-acyl sarcosinates corresponding to the
general formula:
R3C(o)N(CH3)CH2Coo-
and the N-acyl taurides corresponding to the following
general formula:
R4C(o)N(CH3)CH2CH2So3
R3 and R4, for example, may have the meanings mentioned
for R1.
Block polymers or statistical copolymers may be used
as the polyethylene glycol/propylene glycol copolymers
with an average molecular weight of 1,000 to 5,000. The
tooth-cleaning formulations preferably contain statisti-
cal copolymers which are present in a quantity of 0.02 to
5.0% by weight, based on the tooth-cleaning formulation
as a whole.
The mixture of xanthan and the viscosity stabilizer
is incorporated in a liquid carrier. The liquid carrier
consists of water and moisture-retaining substances, for
example polyalcohols such as, for example, glycerol,
sorbitol, xylitol, 1,2-propylene glycol or polyethylene
glycols with an average molecular weight of 200 to 1,500.
These humectants are present in a quantity of 15 to 85~
by weight, based on the tooth-cleaning formulation as a
whole.
Other constituents of the tooth-cleaning formula-
tions according to the invention are:
- polishes such as, for example, precipitated and gel
silicas which do not themselves make a significant
contribution towards thickening, calcium phosphates,
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polymetaphosphates, aluminium oxide and aluminium
hydroxide, the polishes typically being present in
a quantity of 10 to 25% by weight, based on the
tooth-cleaning formulation as a whole,
- solubilizers such as, for example, PEG-30-glycerol
monostearic acid ester, PEG-60-glycerol tri(hydroxy-
stearic acid) ester,
0 - surfactants, for example anionic surfactants, am-
photeric surfactants, nonionic surfactants, prefer-
ably sodium laurylsulfate, sodium fatty alcohol
ether sulfates, fatty acid glycerol ester sulfate,
fatty alcohol EO ethers, fatty alcohol oligosac-
charides,
- water-soluble fluorine components, for example
fluoride and monofluorophosphates,
20 - anti-scale agents, for example phosphonates, prefer-
ably azacycloheptane-2,2-diphosphonate, pyrophos-
phates (disodium salt or tetrapotassium salt), poly-
phosphates (tri- and tetrapolyphosphate),
25 - pH regulators, for example mono-, di-, trialkali
metal monophosphates, citrates,
- sweeteners, for example saccharine, Acesulfam-K,
cyclamate, aspartame,
- flavoring oils and plant extracts, for example
peppermint oil, spearmint oil, eucalyptus oil, anise
oil, fennel oil, caraway oil, menthyl acetate,
cinnamic aldehyde, vanillin and thymol and straw-
berry, raspberry, pineapple, apple and orange
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WO 94/01080 7 PCT/EP93/01701
flavorings,
- microbistatic agents,
- and ethanol and dyes.
The liquid tooth-cleaning formulations according to
the invention have a viscosity at 25C of around 2,000 to
10,000 and preferably in the range from 5,000 to 8,000
mPa s. They retain their fluidity in the long term, even
in the presence of silica abrasives and in conjunction
with a high content of humectants. They may be conven-
iently dispensed dropwise from a storage container by
inverting the container.
The tooth-cleaning formulations according to the
invention are applied in liquid form to the bristles of
a toothbrush in a quantity of about 1 g so that they may
be conventionally used for cleaning teeth. In addition,
the tooth-cleaning formulations according to the inven-
tion may be used as mouthwashes for rinsing the mouth and
throat and also between the teeth. To prepare a mouth-
wash, approximately 1 g of the tooth-cleaning formulation
according to the invention is added to 20 ml of water.
The following Examples are intended to illustrate
the invention without limiting it in any way.
Examples
Liquid tooth-cleaning formulations with the follow-
ing compositions were prepared.
The tooth-cleaning formulations were kept for 1 hour
at 25C in sealed 250 ml screw-top glass bottles, after
which their viscosities were measured. The viscosity
measurements were carried out with a Brookfield Synchro-
Lectric viscosimeter at 25C (type RVF, spindle 3); the
` 21~0370
W0 94/01080 8 PCT/EP93/01701rotational speed was 4 r.p.m.
1. Liquid tooth-cleaning formulation, transParent
Glycerol (86%) 35 %
5 Sorbitol (70%) 30 %
Water (deionized) 9.915%
Ethanol (96% by volume) 5.0 %
Polyethylene glycol 400 3.0 %
Precipitated silica (Sident 12 DS)12.0 %
10 Xanthan 0.15 %
Hydroxypropyl guar (Jaguar HP-60)0.05 %
Sodium laurylsulfate 1.5 %
PEG-30-glycerol monostearic acid ester0.5 %
Azacycloheptane-2,2-diphosphonate (Na salt) 1.15 %
15 Sodium fluoride 0.23 %
Saccharine (sodium salt) 0.3 %
Flavoring oil 1.2 %
Dye 0.005%
Viscosity at 25C: 8,000 mPa-s
2. Liquid tooth-cleaninq formulation, opaque
Sodium laurylsulfate 1.5 %
Water (deionized) 38.697%
25 Azacycloheptane-2,2-diphosphonic acid1.0 %
Sodium hydroxide 0.315%
Polyethylene glycol 400 2.0 %
Xanthan 0.59 %
Hydroxypropyl guar (Jaguar HP-60)0.06 %
Glycerol (86%) 21.0 %
Sorbitol (70%) 20.0 %
Precipitated silica (Sident 12 DS)12.0 %
Sodium fluoride 0.231%
Titanium dioxide 1.0 %
35 Saccharine (sodium salt) 0.1 %
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WO 94/01080 9PCT/EP93/01701
Dye 0.07 %
Disodium phosphate 0.5 %
Flavoring oil 1.0 %
Viscosity at 25C: 6,600 mPa-s
3. Liquid tooth-cleaning formulation, transParent
Sodium laurylsulfate 1.50 %
PEG-30-glycerol monostearic acid ester 0.5 %
10 Cocoamidopropyl betaine 0.18 %
Disodium phosphate 0.2 %
Water 24.668%
Flavoring oil 1.1 %
Sodium hydroxide 0.315%
15 Ethanol (96% by volume) 5.0 %
Glycerol (86%) 28.38 %
Polyethylene glycol (MW 400)3.0 %
Precipitated silica (Sident 12 DS) 12.0 %
Dye 0.001%
20 Xanthan 0.2 %
Sodium fluoride 0.231%
Sorbitol (70%) 21.7 %
Saccharine (sodium salt) 0.2 %
Azacycloheptane-2,2-diphosphonate
25 (sodium salt) 1.0 %
Viscosity at 25C 9,000 mPa s
4. Liquid tooth-cleaning formulation, opaque
30 Sodium laurylsulfate 1.5 %
Water (deionized) 22.365%
Ucon 75-H-450 (statistical PEG/PPG
copolymer, Union Carbide) 1.0 %
Polyethylene glycol 400 2.0 %
35 Xanthan 0.2 %
Glycerol (86%) 28.0 %
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WO 94/01080 10 PCT/EP93/01701
Sorbitol (70%) 30.0 %
Precipitated silica (Sident 12 DS) 12.0 %
Sodium fluoride 0.23 %
Titanium dioxide 1.0 %
5 Saccharine (sodium salt) 0.2 %
Dye 0 005%
Disodium phosphate 0.50 %
Flavoring oil 1.0 %
Viscosity at 25C: 7,200 mPa-s
For use as a dentifrice, approximately 1 g of the
tooth-cleaning formulation are applied in liquid form to
the bristles of a toothbrush and conventionally used for
cleaning teeth.
For use as a mouthwash, approximately 1 g of the
tooth-cleaning formulation are dispersed in 20 ml of
water.
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is present as the viscosity stabilizer in a quantity of
0.1 to 10% by weight.
