Note: Descriptions are shown in the official language in which they were submitted.
W095/064S~PCT~S94109469
~1 7~32
BARING 80DA -~O~ n~A8TE AND TOOTR GEh
CONTAINING 80LUBLE PYROPHO8PHATE 8ALT8
The present invention relates to a dentifrice selected
from the group consisting of a toothpaste and a tooth gel
which contain baking soda and an alkali metal pyrophosphate
salt.
5Calculus, or tartar as it is sometimes called, is the
solid, hard mass of calcified material deposited on and
adhering to the surfaces of the teeth. It is composed of
inorganic salts which make the calculus hard and resistant
to removal. Although not entirely understood, the general
concept is that plaque, which is a sticky film of oral
bacteria and their products, adheres to teeth and becomes
calcified with the ultimate formation on the teeth of a hard
mineral-like material consisting of calcium phosphates.
Calculus is largely calcium phosphates, mainly
hydroxyapatite with varying, but small, amounts of other
inorganic salts.
As the mature calculus develops, it becomes visibly
white or yellowish in color unless stained or discolored by
some extraneous agent. ln addition to being unsightly and
undesirable from an aesthetic standpoint, the mature
calculus deposits can be constant sources of irritation to
the gingiva. Further, the calculus can promote and retain
plaque accumulations. Plaque is recognized as a prime
etiological agent involved in gingivitis and periodontal
disease. Additionally, plaque is porous and can retain
toxic bacterial end products which are also associated with
periodontal disease.
Methods for chemically reducing or preventing calculus
formation have been directed at affecting the process at any
of several stages in its development. One approach is to
develop agents which inhibit the formation of the
crystalline calcium phosphate or hydroxyapatite.
W09S/064S5 PCT~S94/09469
21 70532 ~
A wide variety of chemical and biological agents have
been suggested to retard calculus formation or to remove
calculus after it is formed. The chemical approach to
calculus inhibition generally involves crystal growth
inhibition which prevents the calculus from forming.
Generally, once formed, mechAn;cal removal by the dentist is
n~c~ss~ry and is a routine dental office procedure.
The most widely used tartar control agents in
dentifr~ces are sodium and potassium salts of pyrophosphoric
acid. It is important that the pyrophosphate salt be in a
readily available form so that the pyrophosphate ions (P2O7-
4) contact the enamel surfaces during use. The
bioavailability of the ion is determined by the solubility
of the salt both in the liquid vehicle of the dentifrice and
in the water/expectorant mixture in which the dentifrice is
dispersed during brushing of the teeth.
In a dentifrice cont~;n;ng sodium bicarbonate, i.e.,
baking soda, and the alkali metal salts of pyrophosphoric
acîd, the solubility of the pyrophosphate salt within the
liquid vehicle of the dentifrice is greatly reduced. This
suppression of solubility is due to the excess of sodium
ions placed in solution by the sodium bicarbonate.
Therefore, there is a need to improve the solubility of
alkali metal pyrophosphate salts within a baking soda
toothpaste or a baking soda tooth gel.
The present invention provides a dentifrice in the form
of a toothpaste or tooth gel.
The toothpaste comprises sodium bicarbonate, typically
about 8-65%, preferably about 20-55%, most preferably 40-
50%; an effective amount of an alkali metal pyrophosphatesalt as an anti-tartar agent; and an aqueous solution of
sorbitol in an amount sufficient to dissolve at least about
50~ of the pyrophosphate salt and to provide the desired
consistency to the toothpaste, typically at least about 30-
70~, preferably about 40-60%.
W095/06455 2 l 1~ 5 3 2 PCT~S9~ 169
The tooth gel comprises sodium bicarbonate, typically
about 5-50%, preferably about 10-40%, most preferably about
20-35%; an effective amount of an alkali metal pyrophosphate
salt as an anti-tartar agent; and an aqueous solution of
sorbitol in an amount sufficient to dissolve at least about
50% of the pyrophosphate salt and to provide the desired
consistency to the tooth gel, typically at least about 30-
70%, preferably about 35-60%.
The pyrophosphate ion is more readily available because
tetrasodium pyrophosphate is more soluble in the aqueous
sorbitol solution used herein as the liquid vehicle than in
the conventional aqueous liquid vehicles used in most
toothpastes and tooth gels.
In a toothpaste and a tooth gel, water is typically a
desirable component. However, in the present toothpastes
~and tooth gels, water is not especially desirable and any
additional water (i.e., water over and above that in the
sorbitol solution) comprises only up to about 30%,
preferably only up to 7%, of the composition. The sorbitol
solution is the main liquid vehicle. The water used to
dissolve the sorbitol is that amount which is effective to
solubilize it. Typically, the sorbitol solution is a 70%
aqueous solution.
In translucent gels, where the refractive index is an
important consideration, it is preferred to use higher
ratios of sorbitol or other humectant to water than in
opaque pastes. For a gel the ratio of humectant to water is
typically above 0.5 to 1, preferably above 1 to 1.
Optional, but preferred, components which are typically
included in the toothpastes and tooth gels are organic
thickeners and/or inorganic thickeners, surfactants,
flavoring agents and/or sweetening agents, coloring agents
and/or pigments, an anti-caries agent such as a soluble
fluoride source, buffering agents such as alkali metal
orthophosphates, phosphoric acid, alkali metal
glycerophosphates, tartrates and citrates, and like
Wog5/064ss PCT~S94/09469
?~7~53~ --
components conventionally added to toothpastes and tooth
gels. If desired, a secondary anti-calculus agent can be
included. The optional components should not interfere with
the solubility of the pyrophosphate in the aqueous sorbitol
solution.
The present invention also provides a method of
preventing tartar formation on dental enamel which comprises
contacting the enamel surface in the mouth with a toothpaste
or a tooth gel comprising sodium bicarbonate, an alkali
metal pyrophosphate salt, and an aqueous sorbitol solution,
with the amount of pyrophosphate salt dissolved in the
toothpaste or the tooth gel being sufficient to provide
about 0.5-4.0% pyrophosphate ions in the toothpaste or 0.5-
2% pyrophosphate ions in the tooth gel.
The present invention further provides a method for
increasing the solubility, in a sodium bicarbonate-
cont~; n; ng dentifrice, of alkali metal pyrophosphate anti-
calculus agents by adding an aqueous solution of sorbitol,
as the liquid vehicle, to dissolve the sodium pyrophosphate
salt formed in the presence of the sodium bicarbonate.
Suitable pyrophosphate salts which may be incorporated
in the toothpastes and tooth gels of the present invention
include mono-, di-, tri- or tetra-alkali metal
pyrophosphates and mixtures thereof. The preferred
pyrophosphate salts include disodium pyrophosphate
(Na2H2P2o7)~ tetrasodium pyrophosphate (Na4P2o7)~
tetrapotassium pyrophosphate (K4P2O7), and mixtures thereof.
The pyrophosphates may be employed in their anhydrous as
well as their hydrated forms. The levels of each of these
salts used in the toothpastes are as follows (all are in the
unhydrated form): Na2H2P2O7 - about 1-10%, preferably about
1-5%, Na4P2O7 - up to about 2%, and K4P2O7 - up to about 6%.
The levels of each of these salts used in the tooth gels are
as follows (all are in the unhydrated form): Na2H2P2O7 - 0-
12%, Na4P2O7 - 1-10%, preferably 1-5%, K4P2O7 - 0-6%.
~1 70532
W O 9S/064S5 PCTrUS94/09469
.
Although a particular pyrophosphate salt, e.g.,
disodium or tetrapotassium pyrophosphate, may be the
pyrophosphate initially added to the toothpaste or the tooth
gel, the actual pyrophosphate present in the toothpaste or
tooth gel is dependent on both the final pH of the
toothpaste or tooth gel and the salting-out effect of the
sodium bicarbonate. Typically, the actual pyrophosphate is
tetrasodium pyrophosphate. The quantity of dissolved
pyrophosphate ion present in the toothpaste or tooth gel is
dependent on the solubility, in the precençe of sodium
bicarbonate, of the particular alkali metal pyrophosphate
salt used, in the amount of aqueous sorbitol solution and in
the added water, if present, as well as the final pH of the
toothpaste or tooth gel.
The sodium bicarbonate particles may have a median
particle size of about 5 to 200 microns, preferably about
10-150 microns, most preferably about 20-74 microns. The
bicarbonate particles are incorporated in the toothpaste or
tooth gel in varying amounts, depending upon the desired
properties of the formulation. Higher levels of sodium
bicarbonate, e.g., about 50-65%, allow it to be used as the
sole abrasive. Such formulations remove plaque effectively,
have a desirable low abrasivity, and provide an
exceptionally clean feeling to the teeth and gums after
brushing. Lower levels allow the incorporation of S~con~ry
abrasives and permit the formulation of clearer gels.
To improve clarity in tooth gels less sodium
bicarbonate is used, typically about 10-35%, preferably
about 20-30% and coarser bicarbonate crystals are chosen,
preferably crystals having an average particle size of
greater than 44 microns, most preferably greater than 74
microns. At very low concentrations the clarity of the
tooth gel is increased. If a secondary abrasive is used in
the tooth gel, the abrasive selected is one which will give
a clear or translucent gel. When low levels of sodium
bicarbonate are used in the toothpaste, it is desirable to
wogs/o6455 ~ 7 ~ 5 3 ~ PCT~S94/09469
add an opacifying agent such as titanium dioxide in an
amount of up to about 5%, preferably about 0.1-1%. If one
wishes to convert the present gels into an opa~ue
toothpaste, one should add an opacifying agent such as
titanium dioxide in an amount up to about 5%, preferably
about 0.1-1%.
At very low levels, e.g., less than about 10%, the
bicarbonate still enh~nc~c the clean feeling of the teeth
and gums, but to a lesser degree than when high levels are
used. It also provides effective buffering in the pH range
of 7.5 to 9.5.
Suitable secon~Ary humectants for use herein include
glycerin, propylene glycol, polypropylene glycol, and/or
polyethylene glycol and other conventional humectants.
In addition to the above described required components,
the toothpaste or tooth gel can contain a variety of
conventionally used optional components.
Typically, the toothpastes and tooth gels contain a
natural or synthetic organic thickener or gelling agent. In
the toothpastes the amounts are up to about 2%, preferably
about 0.1-2%. In the tooth gels the amounts are up to about
0.1-10%, preferably about 0.1-2%. Suitable organic
thickeners include sodium carboxymethyl cellulose, starch,
gum tragacanth, carrageenan, xanthan gum, polyacrylate
salts, polyvinylpyrrolidone, hydroxyethylpropyl cellulose,
hydrox~buLylmethylcellulose,hydroxypropylmethylcellulose,
or hydroxyethyl cellulose, which are usually used in amounts
of about 0.1-2.0%. Inorganic thickeners such as hydrated
silicas may also be used in amounts of up to about 10% or
greater in the toothpastes or in amounts of about 0.5%-10%
or greater in the tooth gel.
Conventional abrasives or polishing materials are
useful herein as a secondary abrasive provided they do not
interfere with the solubility of the pyrophosphate salt.
Suitable water-insoluble abrasives for the toothpastes
include sodium metaphosphate, potassium metaphosphate,
W095/06455 2 1 7 0 5 3 2 PCT~S94/09469
.
calcium pyrophosphate, aluminum silicate, zirconium
silicate, hydrated silica, hydrated alumina, bentonite,
and/or the like. Preferred abrasive materials which may be
admixed with the sodium bicarbonate include hydrated silica,
silica gel, or colloidal silica and complex amorphous alkali
metal aluminosilicates. Any of the foregoing water-
insoluble abrasives may be present in the toothpaste in
amounts of up to about 40%, preferably in amounts up to
about 20%, which amount will depend upon the amount of
sodium bicarbonate used.
Suitable water-insoluble abrasives for tooth gels
include colloidal silica, hydrated silica, silica gel,
hydrated alumina, complex amorphous alkali metal
aluminosilicates and/or the like. When visually clear gels
are employed, polishing agents of hydrated or colloidal
silica, alkali metal aluminosilicate complexes, and alumina
are particularly useful since they have refractive indices
close to the refractive indices of the gelling agent-liquid
systems commonly used in the gels. Any of the foregoing
water-insoluble abrasives may be present in the tooth gel in
amounts of up to about 30%, preferably in amounts up to
about 15~, which amount will depend upon the amount of
sodium bicarbonate used.
Organic surfactants are useful herein to achieve
increased cleaning action, to assist thorough and complete
dispersion of the anti-calculus agent throughout the oral
cavity, and to improve the detergent and foaming properties
of the toothpastes and tooth gels. Anionic, nonionic or
ampholytic surfactants may be used, typically in amounts of
about 0.1-3%.
Examples of suitable anionic surfactants are the water-
soluble salts of the higher alkyl sulfates such as sodium
lauryl sulfate or other C8-C18 alkyl sulfates, water-soluble
salts of higher fatty acid monoglyceride monosulfates such
as the sodium salt of the monosulfate monoglyceride of
hydrogenated coconut oil fatty acids, alkyl aryl sulfonates
WO95~J~5S ~ 7 o 53~ PCT~S93~S~9
such as sodium dodecyl benzene sulfonate, higher alkyl
sulfoacetates, higher fatty acid esters of l,2-dihydroxy
propane sulfonate, and the substantially saturated higher
aliphatic acyl amides of lower aliphatic amino carboxylic
acids such as C12-C16 fatty acids, alkyl or acyl radicals,
and the like. Examples of the last mentioned amides are N-
lauroyl sarcosinate and the sodium, potassium, and
ethanolamine salts of N-lauroyl, N-myristoyl, or N-palmitoyl
sarcosinate which should be substantially free from soap or
similar higher fatty acid materials.
Other suitable surfactants include non-ionic agents
such as the condensates of sorbitan monostearate with
ethylene oxide, the condensates of ethylene oxide with
propylene oxide, or the condensates of propylene glycol
(available under the trademark "Pluronics"). Other examples
of water-soluble nonionic surfactants useful herein are the
condensation products of ethylene oxide with various other
compounds which are reactive therewith and have long
hydrophobic ~h~;nc (e.g., C10-C20 aliphatic ch~in~) which
condensation products ("ethoxamers") contain hydrophilic
polyoxyethylene moieties, such as condensation products of
polyethylene oxide with fatty acids, fatty alcohols, fatty
amides, or polyhydric alcohols (e.g., sorbitan
monostearate).
The various surfactants may be utilized alone or in
admixture with one another. In toothpastes and tooth gels,
the total amount used is preferably about 0.05%-5%, more
preferably about 0.1%-2.0%.
Sweetening agents are also useful herein. They include
saccharin, sucralose, dextrose, levulose, aspartame, D-
tryptophan, dihydrochalcones, acesulfame, sodium cyclamate,
and calcium cyclamate. They are generally used in amounts
of up to about 2%. Also useful as sweetening agents are
xylitol and mannitol in amounts of up to about 3% and 5%,
respectively, in toothpastes and up to about 5% in tooth
gels.
Wo95/06455 2 1 ~ Q S 3 2 PCT~S94109469
Anti-microbial agents can be included in the
toothpastes to help inhibit plaque formation and gingivitis
or to reduce mouth odor. For example, cationic anti-
A microbial agents such as cetyl pyridinium chloride or
5 benzothonium chloride can be used. Bis-biguanides are also
effective. Such agents include chlorhexidine (1,6-bis tN5-
p-chlorophenyl-N-biguanido] hexane), and the soluble and
insoluble salts thereof and related materials such as 1,2-
bis (N5-p-trifluoromethylphenyl-N1-biguanido) ethane which
are described more fully in U.S. Pat. No. 3 937.807 (issued
Feb. 10, 1976 to Haefale), Belgian Pat. No. 843 244
(published Dec. 22, 1976) and Belgian Pat. No. 844,764
(published Jan. 31, 1977). If present, the secondary anti-
microbials generally comprise about 0.01-0.5% of the
composition. When using cationic agents, it is generally
necessary to avoid using anionic surfactants in the
formulation. Non-ionic anti-microbials such as triclosan
can be used. These materials have the advantage of not
losing efficacy in the presence of anionic surfactants.
Soluble complex phosphate salts other than the
pyrophosphates may be used as secondary anti-calculus
agents, e.g., tripolyphosphates and hexametaphosphates.
The toothpastes and tooth gels can include a water-
soluble fluoride ion source which is effective both as a
pyrophosphatase inhibitor and as an anti-caries agent.
Suitable fluoride ion sources include inorganic fluoride
salts such as soluble alkali metal or alkaline earth metal
salts, e.g., sodium fluoride, potassium fluoride, sodium
fluorosilicate, ammonium fluorosilicate, sodium
fluorozirconate and sodium monofluorophosphate. Alkali
metal fluorides such as sodium fluoride, sodium
monofluorophosphate, and mixtures thereof are preferred.
The amount of the soluble fluoride ion source in the
dentifrice is dependent on the particular compounds used and
the type of dentifrice, but it must be incorporated in an
effective, but nontoxic amount, generally up to about 5.0%.
W095/06455 PCT~S94/09469
~ 7 ~53~ ~
Any suitable minimum amount of fluoride may be used, but it
is preferable to employ a quantity sufficient to release
about 50 to 3500 ppm, preferably about 850-1500 ppm, of
fluoride ions. In the case of sodium fluoride, the fluoride
ion source is present in an amount from 0.05-0.65%,
preferably about 0.18-0.35%. In the case of sodium
monofluorophosphate, the amount is about 0.2-2%, more
typically about 0.65%-1.20%.
Various other materials mfay be incorporated in the
toothpastes and tooth gels. Examples thereof are coloring
and whitening agents, preservatives, silicones, and/or
chlorophyll compounds. These adjuvants are incorporated in
the toothpastes and tooth gels in amounts which do not
substantially adversely affect the properties and
characteristics desired and are selected and used in
effective amounts, depending upon the particular adjuvant
and the type of toothpaste or tooth gel involved.
The pH of the toothpastes and tooth gels herein range
from 7.0 to 10.0, preferably from 7.5 to 9Ø The pH is
preferably achieved through a proper balancing of the
bicarbonate and other additives.
The toothpastes and tooth gels herein are made using
conventional mixing t~hn; ques and used in a conventional
manner.
The following examples further illustrate the present
invention, but it is understood that the invention is not
limited thereto. All amounts and proportions referred to
herein and in the appended claims are by weight and
temperatures are in degree Celsius unless otherwise
indicated.
mple 1
The following toothpaste cont~;n;ng about 1.3%
pyrophosphate all in solution was prepared.
Sodium bicarbonate (mean 43.374
particle size < 35)
Tetrasodium pyrophosphate 2.000
W095/06455 2 1 70532 PCT~S94/09469
.
Sodium fluoride 0.243
Sorbitol (70% aqueous solution) 40.100
Glycerin 4.104
Polyethylene glycol (PEG-8)1.000
Sodium carboxymethyl cellulose0.700
(9M31F)
Distilled water 5.279
Sodium saccharin 1.000
Sodium lauryl sulfate 0.300
Sodium lauroyl sarcosinate1.000
(30% solution)
Flavor 0.900
TOTAL 100.000
Ex~mple 2
The following tooth gel containing about 1.3%
pyrophosphate ion all in solution was prepared.
Sodium bicarbonate (Grade 2)31.354
Tetrasodium pyrophosphate 2.000
Sodium fluoride 0.243
Sorbitol (70% aqueous 40.100
solution)
Glycerin 4.104
Polyethylene glycol (PEG-8)1.000
Sodium carboxymethyl cellulose0.600
(9M8F)
Distilled water 5.279
Sodium saccharin 0.650
Thicke~;ng silica (Sylox 2)4.500
Hydrated silica (Sylodent 700)8.000
Sodium lauryl sulfate 0.500
Sodium lauroyl sarcosinate1.670
(30% solution)
Flavor 0.950
TOTAL 100.000
W095/064S5 PCT~S94/09469
2.~7053~ ~
~Y~mple3 3-6
The following are representative toothpastes.
3 4 5 6
Sodium bicarbonate42.28755.000 8.00020.000
Tetrasodium 2.000 2.000 6.0004.000
pyrophosphate
Tetrapotassium0.000 0.000 0.0003.000
pyrophosphate
Hydrated silica0.000 0.000 0.0004.300
abrasive
Thickening silica0.0000.000 0.0003.000
Titanium dioxide0.0000.000 0.0000.200
Calcium pyrophosphate0.000 0.0008.000 0.000
Sodium fluoride0.243 0.243 0.2430.243
Sorbitol (70%40.100 40.100 40.10040.100
solution)
Glycerin 5.000 5.000 5.0005.000
Polyethylene glycol 0.000 0.0001.000 1.000
(PEG-8)
Sodium carboxymethyl 0.600 0.6000.600 0.600
cellulose
Distilled water6.000 5.279 5.27910.000
Sodium saccharin0.6500.650 0.6500.650
Sodium lauryl sulfate0.500 0.5000.500 0.500
Sodium lauroyl1.670 1.670 1.6701.670
sarcosinate
(30% solution)
Flavor 0.950 0.950 0.9500.950
W095/06455 2 1 7 0 5 32 PCT~S94/09469
.
TOTAL 100.00 100.00 100.00 100.00
O o o O
Approximate % of 80% 50% 75% 55%
pyrophosphate which
is in solution
Examples 7-10
The following are representative tooth gels.
' 10 7 8 9 10
Sodium bicarbonate25.00050.000 5.000 12.000
Tetrasodium 2.000 1.000 6.000 4.000
pyrophosphate
Tetrapotassium 0.000 0.000 0.000 3.000
pyrophosphate
Sodium fluoride 0.243 0.243 0.243 0.000
Sodium o.ooo o.000 .ooo 0.780
monofluorophosphate
Sorbitol (70% aqueous 44.882 39.984 62.000 58.692
solution)
Glycerin 5.150 10.000 5.000 6.220
Polyethylene glycol0.0001.500 1.000 2.000
(PEG-8)
Sodium carboxymethyl0.6000.300 0.600 0.300
cellulose
Sodium saccharin0.650 0.650 0.500 0.800
Hydrated silica 4.500 0.000 12.000 6.000
abrasive (Sylodent 700)
W095/06455 PCT~S94/09469
~7053~ ~
Thickening silica8.000 0.000 6.000 4.000
(Sylox 2)
Sodium lauryl sulfate0.5000.5001.000 1.500
Sodium lauroyl 1.670 0.870 0.000 0.000
5 sarcosinate
(30% solution)
Flavor 0.800 0.950 0.655 0.700
Color 0.005 0.003 0.002 0.008
TOTAL 100.00 100.00 100.00 100.00
O O O O
Approximate % of 100% 100% 65% 60%
pyrophosphate which is
in solution
~xamples 11-14
The following are additional representative toothpastes
11 12 13 14
Sodium bicarbonate35.00043.22014.979 65.0t)0
Tetrasodium 0.000 0.000 2.500 2.000
pyrophosphate
Tetrapotassium 3.400 5.000 0.000 0.000
pyrophosphate
Disodium dihydrogen0.0000.200 0.000 0.0t)0
pyrophosphate
Hydrated silica 5.500 0.000 5.000 0.000
abrasive
Thickening silica0.000 0.000 5.000 0.000
14
W095/06455 2 1 7 0 5 3 2 PCT~S94/09469
.
Titanium dioxide 0.100 0.000 0.500 0.000
Sodium fluoride 0.243 0.000 0.221 0.243
Sodium 0.000 0.780 0.000 0.000
monofluorophosphate
Sorbitol (70% solution)44.657 40.100 35.000 24.327
Xylitol 3.000 0.000 0.000 0.000
Mannitol 0.000 0.000 5.000 0.000
Glycerin 4.000 0.000 4.000 4.000
Polyethylene glycol1.0001.000 0.000 1.000
(PEG-8)
Sodium carboxymethyl0.3000.600 0.800 0.300
cellulose
Distilled water 0.000 6.000 25.000 0.000
Sodium saccharin 0.650 0.700 0.500 0.800
Sodium lauryl sulfate1.2000.300 0.800 0.330
Sodium lauroyl 0.000 1.000 0.000 1.000
sarcosinate
(30% solution)
Flavor 0.950 1.100 0.700 1.000
TOTAL 100.000100.000 100.000 100.000
Approximate % of 100% 70% 80% 75%
pyrophosphate which is
in solution
W09S/OG45S PCT~S94/09469
53~ --
2x mple~ 15-18
The following are additional representative tooth gels.
16 17 18
Sodium bicarbonate 32.000 43.220 29.500 20.000
Tetrasodium 0.000 0.000 2.500 5.000
pyrophosphate
Tetrapotassium 3.400 5.000 0.000 0.000
pyrophosphate
Disodium dihydrogen 0.000 0.195 0.000 0.000
pyrophosphate
Sodium fluoride 0.243 0.000 0.243 0.000
Sodium 0.000 0.780 0.000 0.780
monofluorophosphate
Sorbitol (70% aqueous43.15740.10040.000 42.000
solution)
Xylitol 5.000 0.000 0.000 0.000
Mannitol 0.000 0.000 4.882 0.000
Glycerin 0.000 0.000 5.000 0.000
Polyethylene glycol 1.000 1.000 1.000 0.000
(PEG-8)
Sodium carboxymethyl0.300 0.600 0.600 0.300
cellulose
Distilled water 0.000 6.000 0.000 9.367
Sodium saccharin 0.646 0.700 0.650 0.800
Hydrated silica abrasive4.1000.0004.500 4.000
(Sylodent 700)
W095~q~5 ~1 7 ~ 5 3 2 PCT~S94/09469
.
Thickening silica (Sylox8.000 0.000 8.000 15.000
2)
Sodium lauryl sulfate 1.200 0.300 0.500 0.330
~odium lauroyl 0.000 1.000 1.670 1.000
5 sarcosinate
(30% solution)
Flavor 0.950 1.100 0.950 1.000
Color 0.004 0.005 0.005 0.003
TOTAL 100.00 100.00 100.00100.000
O O O
Approximate % of 100% 55~ 100% 50%
pyrophosphate which is
in solution
Ex~mple 19
This example shows the effect of sodium bicarbonate
(NaHCO3) on the solubility of tetrasodium pyrophosphate.
Wt % of P2O7-4 in Solution
With Saturated
Without NaHCO3 NaHCO3
Distilled Water 4.03 1.77
Glycerin 0.04 0.12
70% Aqueous Sorbitol Solution 5.97 4.18
18% Aqueous Mannitol Solution - 2.09
60% Aqueous Xylitol Solution - 2.44
The results show that, in the presence of sufficient
sodium bicarbonate to saturate the water, the solubility of
the pyrophosphate ion (P2O7-4) was suppressed from 4.03~ to
1.77%. The results show that, in the absence of sodium
W095/064S5 ~ 7 ~ 5 3 ~ PCT~S9~91~9
bicarbonate, the pyrophosphate is more soluble in the 70%
aqueous sorbitol solution than it is in the distilled water.
While the presence of the bicarbonate in the aqueous
sorbitol solution also suppressed the pyrophosphate
solubility, the decrease was not as great as that observed
with water. The pyrophosphate was not soluble in glycerin
in either case. The results further show that other similar
polyols, i.e., mannitol and xylitol, were not as effective
as sorbitol, in increasing pyrophosphate solubility in the
presence of bicarbonate.
~xamPle 20
This example shows the solubility of tetrasodium
pyrophosphate in various dentifrice solvent systems
saturated with sodium bicarbonate. The percent solubility
of the pyrophosphate ion (P2O7-4) is given as weight %.
Water* ÇlYcerin* 70% Sorbitol Wt. ~ P2Q7-
Solution
1 0 0 1.77
0 1 0 0.1
0 0 1 4.1
1/2 1/2 0 0.44
1/2 0 1/2 2.1
0 1/2 1/2 1.73
1/3 1/3 1/3 1.01
2/3 1/6 1/6 1.15
1/6 2/3 1/6 1.48
1/6 1/6 2/3 2.0~3
*Weight fraction of solvent system.
Woss/064SS 2 1 7 0 ~ 3 2 PCT~S94/09469
.
The results show that the best solubility (4.18%) was
in the 70% aqueous sorbitol solution and the worst
solubilities were in solvent systems cont~; n; ng no aqueous
sorbitol solution (0.12% for glycerin and 0.44% for a
glycerin/water mixture).
In addition to the levels and combinations of
ingredients shown in these examples, others can be used
which are consistent with the invention disclosed and
claimed herein.
