Note: Descriptions are shown in the official language in which they were submitted.
This invention relates to a visually clear dentifrice.
More particularly, it relates to a visually clear dentifrice con-
taining a liquid vehicle comprising maltitol and wa~er.
In recent years, visually clear dentifrices have been
developed which contain a dental cleaning or polishing agent.
Such dental cleaning or polishing agents generally have been
siliceous in nature with refractive indices of about 1.44 - 1.47.
Use of such materials has permitted preparation of dentifrices
in which the refractive index of the liquid vehicle matches
that of the siliceous polishing agent~ Thi.s has been typically
accomplished using glycerin and/or sorbitol as humectants in the
; liquid vehicle, si.nce glycerin has a refractive index of 1.~73
and sorbitol (70% water solution) of 1.460 llowever, since
water has a rcfractive index of 1.333, only very little formula
water ~i.e. separate from that associated with other components
; such as sorbitol) could be used without substantially reducing
the refractive index and causing diminution or loss of clarity.
Efforts have been made to develop visually clear denti-
frices in which less glycerin and/or sorbitol could be tolerated.
For ins~ance: (1) In United States Patent 3,842,167 to Block et al
maltodextrin was added as a non-humectant component of the
liquid phase to reduce the amount of glycerin and/or sorbitol
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::
needed; (2) in U. S. Patent 3,927,202 to Harvey et al various
phosphate non-siliceous polishing agents were used which per-
mitted modification of the refractive index range of the liquid
vehlcle; in U. S. Patent 4,007,260 to Kim a silica polishing
agent having a refractive index o~ about 1.410 to 1.440 was used.
It i9 an advantage of this invention that a visually clear
dentifrice is provided in which a liquid vehicle i~ present
which comprises ~a humectant having a refractive index of about
1.48 ~e.g. about 1.4750 to about 1.4849) and water.
It is a further advantage of this inven~ion that increased
free water can be used above that prev$ously used in visually
clear dentifriceæ containing an alkali metal aluminosllicate
polishing agent naving a refractive index of about 1.44 to ahout
1.47 and a humecta~t having a refractive index of ahout 1.48.
The amount of water 15 not so h$gh as to result in undesirable
drying of the dentifrice due to substantial evaporation of
water, particularly in view of the presence of maltitol~ Other
advantages will be apparent from consideration of the following
specific~tion.
In accordance with certain of i~s aspects, this invention
relates to a visually clear dentifrice conta1ning a vehicle
comprising about 0.5-10% by weight of a solid portlon of gelling
agent and about 50-94.5YO by weight of a liquid portion compris-
ing (a) a humectant ~herein maltitol of refractive index of
about 1.48 is present as the sole or na~or non-water componen~
of said llquid vehicle and (b) water in amount to provide a
refractive index to said liqtlid vehicle of between about 1.44
a~d about 1.47, said vi5u811y clear dentifrice also containing
about 5-50% by weight of a complex alkali metal aluminosilicate
pollshing agent navlng a refractive index between about 1.44 to
about 1.47.
--2--
Ihe li~uid portion oE tile vehicle comLlrises about 50 -
94.5 % by weigh-t of the visually clear dentiEr:ice, ~preferably
about 55 - 80%. It contaills a h-mect~mt wh:icll is all or a major
amount ~i.e. above about 50 %) of maltitol. Maltitol* is essen-
tially a glycosyl sorbitol, i.e. 4-D-~-D-glycopyranosyl-D-glucitol,
having the structural Eormula:
CH20~1
~ HO-CH
HO o C~l
H HO HC-OH
HO-CII
CH20H
It is prepared by hydrogenation oE maltose. In substantially pure
form i-t is a glassy solid. It readily dissolves in minor amounts
of water and its solutions containing at least about 73 % oE
maltitol and up to about 27 % of water are observed to have refrac-
tive indices of about 1.48. ~i.e. about 1.4750 to 1.4849). When
incorporated into a dentifrice together with separately added wa-ter
of refractive index of about 1.333, the liquid vehicle can be ad-
justed to provide a refractive index of about 1.44 to about 1.48.
Typically, about 5 - 25 % by weight of water can produce such a
refractive index, with lower amounts of water (e.g. about 1.47)
and higher amounts of water (e.g. about 15 - 23 %) producing a
lower refractive index ~e~g. near 1.44). Preferably, the refrac-
tive index of the liquid vehicle is about 1.44 to 1.'17 and is
attained with about 5 - 10 % by weight of formula water. The
water portion of the dentifrice refers to water which is separate
or unassociated with water used to dissolve humectant.
*Trade Mark - 3 -
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Ma:lti-tol need not be pure in the sense of heing the sugar
a]cohol derivative of pure maltose. Commercial maltitol consists
of maltitol with minor amounts of the sugar alcohols derived from
maltotritose, maltotetrose, and related low molecule weight malto-
dextrin portions of corn syrup and with minimal amounts of D-
sorbitol. Thus a commercial "hydrogenated starch hydrolysate"
made from high maltose content corn syrup would also be useful in
the practice of this invention.
Maltitol has been recommended for dentifrice use,
albeit not as a principal humectant for visually clear dentifrice
containing a polishing agent.
In this regard reference may be had to "Caries Research",
Vol. 14, Issue 2, ~19~0) pages 67-74, Rundegren et al (maltitol
observed not to contribute to demineralization); "Shigaku",
Vol. 60, Issue 6 ~1973), pages 760 - 765, Matsuo ~maltitol observed
not to be fermented by Streptococcus salivarius, S.); "Acta
Odont. Scand", Vol. 37, Issue 2, ~1979) pages 103 - 115, Bi.rkhed
et al and "Caries Research", Vol. 12, Issue 3 ~1978), pages 128 -
136, Birkhed ~observations made on plaque) "Acta Odont. Scand,
Vol. 35, Issue 5 (1977), pages 257 - 263, Edwardsson et al
(observations made on oral bacteria); Japanese Patent Publication
73 10241 of Sunstar (describing maltitol as a mouthwash compo-
nent). Further, maltitol may be a component of a vari.ant of
sorbitol known as "non-crystalizing sorbitol", which may be used
as a dentifrice humectant. ~lowever, the substantial content of
sorbitol in non-crystalizing sorbitol is such that a refractive
index of about 1.48 is not achieved, thereby reducing water-
humectant vehicle formulation variation ability in comparison
with that of the present invention. It is also noted that fatty
acid esters of maltitol and other sugar alcohols are disclosed
as dentifrice taste components in British Patent Specification
2 038 182 of l.ion Dentifrice Company.
If desired, the liquid vehicle of the visually clear
den~ifrice of the present invention may be a minor amount (i.e.
less than about 50%) of a humectant in addition to ma]titGl or
even a non-humectant liquid vehicle component such as maltodextrin.
Such humectants as glycerin, sorbitol (typically 70% solution
of sorbitol), polyethylene glycol 400, polyethylene glycol 600,
and the like may be used. Preferably, maltitol comprises above
about 50% by weight of the non-water portion of the liquid
vehicle, preferably about 65 - 100%. Maltitol is typically
provided in about 73 - 85% solution and is available from suppliers
including Aldrich Chemical Company, Merck and Co. Inc., Imperial
Chemicals Industries, Pfizer Inc., Lonza, Roquette ~reres, and
Hayashibara Chemical Laboratories.
The solid portion of the vehicle is a gelling agent,
such as the natural and synthetic gums and gum-like materials,
such as Irish Moss, gum tragacanth, alkali metal carboxymethyl
cellulose and hydroxyethyl carboxymethyl cellulose, polyvinyl
pyrrolidone, starch, xanthan, guar gum, sodium alginate, hydro-
philic colloidal carboxyvinyl polymers, such as those sold under
the ~rademark Carbopol 934 and 940 and synthetic inorganic
silicated clays such as those solid under the trademark Laponite
CP and Laponite SP. These grades of Laponite have the formula
~Si8Mg5 lLio 6H7 624~ Na o 6 The solid portion of the
vehicle is typically present in amount up to about 10% by weight
of the dentifrice and preferably about 0.25 - 5% by weight. When
employed, grades of Laponite are typically used in amounts of
about 1 - 5% by weight.
-- 5 --
Synthetic finely divided sil:icas such as those sold
under the trade marks Cab-0-Sil M-5, Syloid 2~4, Syloid 266,
Aerosil D200 and mixtures thereof, may also be employed in amounts
of about 0.5 - 20% by weight to promote thickening or gelling and
clarity of the dentifrice.
The complex alkali metal aluminosilicate salt des-
cribed above is typically alkaline in nature, typically a sodium
salt~ and effectively promotes oral hygiene. It is an amorphous
powder which further has the property that when incorporated in
the vehicle the particles thereof become substantially invisible.
Thus, a particle size for the polishing agent is up to about 40
microns, preferably 1 - 2 microns. The typical moisture content,
measured by loss on ignition, is about 5 - 20% by weight of the
agent and the typical content of alkali metal oxide, such as
sodium oxide is up to about 10% by weight. Alumina is typically
present in amount of about 10% by weight and silica typically
in amount of at least about 70% by weight, typically the agent
has a loose bulk density o:f up to about 0.2 g/cc preferably about
0.07 - 0.12 g/cc. The amount of alumina in the aluminosilicate
is typically about 0.1 - 3% by weight and preferably about 1%.
Desirably the refractive index of the aluminosilicate is within
about 0.005 units~ typically within about 0.001 of that of the
liquid vehicle.
The polishing agent typically comprises about 5 - 50% by
weight of the dentifrice formulation, preferably about 10 - 30%
by weight.
The complex alkali metal aluminosilicate salt appears to
contain interbonded silica and alumina having Al - - 0 Si bonds
as described by Tamele "Chemistry of the Surface and the Activi*y
of Alumina-Silica Cracking Catalyst1', Discussions of the Faraday
Society, No. 8, Pages 270 - 279 ~1~50) and particularly at page 273,
Figure 1, curve, 3 wherein the interaction between silica and
-- 6 --
aluminum ions is potentiometrically detected. Further literature
describing this type of complex includes Milliken et al, "The
Chemical Characteristics and Structures of Cracking Catalysts",
Discussion of the Faraday Society, No. 8, pages 279-290 (1950)
and particularly the sentence bridging pages 2~4-285. These
complexes clearly differ from sillca gel as is described by
Plank et al. "Differences Between Silica and S~lica-Alumina
Gels I. Factors Affecting the Porous Structure of These Gels,"
Journal of Colloid Science, 2, pages 399-412 (1947) and Plank,
"Differences Between Silica and Silica-Alumina Gels II. A Pro-
posed Mechanism for the Gelation and Syneresis of The~e Gels,"
Journal of Collold Science 27 pages 413-427, (1947) in which
formation of the Al _ O ~ Si bond is described at pages 419-422.
The aluminosilicate may be described as silica containing
combined alumina.
In the prior art, maltitol ~as disclosed for use in denti-
frlces in Japanese P~tent Publicatio~ 15120/65 ~Patent No.
4619281) and 73¦10241. In the former, siliceous polishing agent
is not disclosed; in the latter sllicic anhydride is mentioned
as a polishing agent. However, it has been found that when
silicic anhydride, such ~s colloidal silica xerogel available
from Grace Davison as Syloid 74 is employed in a visually clear
dentifrice cont~inlng msltitol, the dentifrice qulckly becomes
dull in appearance and dries when exposed to air to become a
hardened opacified product. When the complex alu~inosilicate
of the preæent in~ention is employed the dentifrice substantially
retains its desirable clear appearance and rheology.
Organic surface-active agents may be used in the compositions
of the present invention to achieve increased prophy~actic
action, aSSiBt in achievlng thorough and complete dispersion of
_7-
,,
the instant compositions ~hroughout the oral cavity, and render
the instant compositions more cosmetically acceptable. The
organic surface active material may be anionic, nonionic,
ampholytic) or cationic in nature, and it is deslrable to employ
as the surface active agent a deterslve materlal which $mparts
to the composition detersive and foaming properties. Suitable
types Gf such detergents are water-soluble salts of higher fatty
acid monoglyceride monosulphates, such as the sodium salt of the
monosulphated monoglyceride of hydrogenated coconut oll atty
acids, higher alkyl sulphates, such as sodlum lauryl sulphate,
alkyl aryl sulphonates, such as sodium dodecyl benzene sulphonate,
olefin sulphonatesp such as sodium olefin sulphonate ln which
the olefin group contains 12-21 carbon atoms, higher alkyl
snlphoacetates, higner fatty acid ester of 1,2-dihydroxy propane
sulphonates, and the substantially saturated hlgher aliphatic
acyl amides of lower aliphatic amino carboxylic acid compounds~
such as ~hose having 12-16 carbons ln the fatty acid, alkyl or
acyl radicals, and the like. Examples of the last mentioned
amides are N-lauroyl sarcosine and the sodium, potassium, and
ethanolamine salts of N-lauroyl, N-myristoyl or ~-palmitoyl
sarcosine, whlch could be substant~ally free from soap or
similar higher fatty acid material ~hich tends to substantially
reduce the effect of these compounds. The use of these sarco~ine
compounds in dentilrice compositions of the present inventlon
is particularly advantageous since these materlals exhiblt a
prolonged and marked effect in the inhibltion of acid formation
in the oral ca~ity due to carbohydrates breakdown in addition
to exerting some reduction in the solubility of tooth enamel
in acid solutions.
Other partlcularly suitable surface active materials include
nonionic agents such as condensates o~ sorbitan monostearate
--8--
with appro~imately 20 moles of ethylene oxide9 condensates of
propylene glycGl ("Pluronics") and amphoteric agents such as
quaternized imidazole derivatives, which are available u~der the
trademark "Mi~anoll' such as Miranol G2M. Cationic surface active
germicides and antibacterial compounds such as di-isobutylph~no-
xyethoxyethyl dimethyl benzyl ammonium chloride, ben~yl dlmethyl
stearyl ammonium chloride, tertiary amines having one fatty
alkyl group (of from 12-18 carbon atoms~ and two (poly) exye~hy
lene groups attached to the nitrogen (typically containing a
total of from about 2 to 50 ethano~y groups per molecule) and
salts thereof with acids, and compounds of the structure.
(IH2cH2o)zH CH2CH2~)xd
R-N C~2CH~CH2N (cH2cH2o3yH
where R i3 a fatty al~yl group containing fro~ abou~ 12 to 18
carbon atoms, and x, y and z total 3 or h-lgher, as well a~ salts
thereo with mineral or organic acids, may al~o be used. It is
preferred to use from about ~.05 $o 5~ by weight of the foregoing
surface-active ma~erials in the instant dentifrice.
An alkall metal fluorine-providing compound may be employed
in the dentlfrice of the invention. The alkali metal fluorine-
providing compound includes sodium fluor~de, potassium fluoride,
lithium fluoride, ammonium fluoride and complex fluorides, par-
ticularly alkali metal monofluorophosphates. These compounds
exhibit satisfactory retentions of soluble fluoridP in denti-
frlces of the instant invention. In particular, the level of
retention of monofluorophosphate lon as fluoride wlth the alkali~`
metal monof luorophosphates is quite high. The fluorine-contain-
ing compound ls emp:LoyPd in amount which provides an effective
non-toxic amount of fluorine-containing ion to thP dentifrice
_g_
,,
~7~3~6
typlcally about 0.01-1% by weight preferably about 0.1% f luorine .
Thus, sodium fluoride i~ typically employed ln amount of about
0.02-2% by weight, pref erably about 0.2X, and sodium monofluoro-
phosphate, Na2P03F, in amount of about 0.1-7.6% by weight,
preferably about 0.76%.
The alkali metal monofluorophosphat~ which may be employed
include sodium monofluorophosphate9 lithium monofluorophosphate,
potasslum monofluorophosphate and ammonium monofluorophosphate.
The preferred salt is sodium ~onofluorophosphate, ~a2P03F, which,
as co~mercially available, may vary cons~dersbly ln purity. It
may be used in atly suitable purity provided that any impurities
do not substantially adversely affect the desired properties.
In general, the purlty is desirably at lea~t about 80%. For best
results, it should be at least 85%, and preferably at least 90%
by weight of sodium mo~ofluorophospha~e wi~h the balance being
primarily impuritie~ or by-products of manufacture such as
sodium fluoride, water-soluble sodium phosphate salt, and the
like. Expressed ln another way, the sodium monofluoropho~phate
employed should hava a total fluoride content of about 12%,
preferably about 12.7%; a eontent of not ~ore than 1.5%, pre-
ferably not more than 1.2% of free sodium fluoride; and a sodium
monofluorophosphate content of at least 12%, prefersbly at least
12.170, all calculated as fluGrine.
Other monofluorophosphate salts whlch may be used in the
ins~ant inventlon include monofluoropolyphosphates such as
4PgOgF, K4P309F~ 4)4P30gF, Na3KP~09F9 ~N~)3MaP309F and
Li4P309F-
Any suitable flavor~ng or sweetenlng ma~erials may beemployed in for~ulating a flavor for the compositions of tbe
present invention. E~amples of sui~able ~lavouring con~tituents
include the flavouring oil~, e.g., olls of ~pearmint, peppermi~t,
_10 -
3'7~
wintergreen, sassafras, clove, sage, eucalyptlls, majoram, cinna-
mon, lemon and orange, as well as methylsalicylate. Suitable
sweetening agents include, sucrose, lactose, maltose, sorbitol,
sodium cyclamate, perillartlne and saccharin. Suitable,
flavor and sweetening agents may together comprise from about
0.01 to 5% or more of the compositions of the instant invention.
Chloroform may also be used.
Antibacterial agents may be employed in the prepara-
tions of the instant invention in an amount of about 0.01 to 5% by
weight. Typical antibacterial agents include
Nl-(4-chlorobenzyl)-N5-(2,~-dichlorobenzyl)biguanide;
P-chlorophenyl biguanide;
~-chlorobenzhydryl biguanide;
4-chlorohenzhydrylguanylurea;
N-3-lauroxypropyl-N5-p-chlorobenzylbiguanide;
1,6-di-p-chlorophenylbiguanidohexane;
1,6-bis(2-ethylhexylbiguanide)hexane;
l-(lauryldimethylammonium)-8-(p-chlorobenzyldimethylammonium)
octane dichloride;
5,6-dichloro-2-guanidinobenzimidazole;
Nl-p-chlorophenyl-N5-laurylbiguanide;
5-amino-1~3-bis(2-ethylhexyl)-5-methylhexahydropyrimidine;
and their non-toxic acid addition salts.
Various other materials may be incorporated in the pre-
parations of this invention. Examples thereof are colouring or
whitening agents or dyestuffs, preservatives, silicones, chloro-
phyll compounds, ammoniated materials such as urea, diammoniumphos-
phate and mixtures thereof, and other constituents. The adjuvants
are incorporated in the instant compositions in amounts which
do not substantially adversely affect the properties and character-
istics desired and are selected and used in proper amounts
depending upon tlle particular type of preparation involved.
- 11 -
7~
Tlle dentiEricos should ilave a p~l prac-ticable for use. A
moderately acid to alkaline pll is preEerred.
The following specific examples are further illustrative
of the nature of the present invention, although it is understood
that -the invention is not linlited thereto. All amounts are by
weight unless otherwise indicated.
EXAMPLF. 1
The following denti:Erices are prepared:
PARTS
A B
Maltitol* (80 %) 59 % 59 0
Deionized water 10.74 10.7~
Sodium monofluorophosphate 0.76 0.76
Sodium saccharin 0.25 0.25
Sodium carbox~nethyl cellulose 0.35 0.35
Polyethylene glycol (Carbowax* 600) 3.0 3.0
Silica xerogel (Syloid* 74) 18.0
Sodium aluminosilicate ~silica
containing about 1 % combined
alumina - Zeo 49B*-Huber) - 18.0
Sodium lauryl sulfate 1.2 1.2
Flavor 1.2 1.2
The reEractive index of Syloid 74 in Dentifrice A and
Zeo 49B in Dentifrice B is within about 0.005 unit of that of the
liquid vehicle of each dentifrice.
Each of the dentifrices are initially shiny and clear.
However, after one week at room temperature, Dentifrice A, contain-
ing silica xerogel, becomes dull in appearance and upon being left
exposed to air becomes opaque white-like color and quite hard.
~nder these sc~ne conditions, dentifrice B remains shiny
*Trade Mark - 12 -
"'~
and clear and continues to have desirable flow characteristics.
_XAMPLE 2-4
The following visually clear dentifrice~ are prepared ln
which the refractive index of the polishing a~ent is within 0.005
unit of that of the liquid vehicle.
PARTS
_ _ 3 4
Maltitol (73%) 62.0 - -
Maltitol (80%) - 60.0 48.0
Deionized water 7.24 16.6 22.6
Sodium monofluorophosphate0.76 0.76 0.76
Sodium saccharin 0.25 0.24 0.24
Sodium benæoate 0.50 -- -
Sodium carboxymethyl cellulose 0.35 0.4
Xanthan - - 1.4
Polyathylene glycsl (Carbowax 600) 3.00
Sodium aluminosllicate ~Silica con-
taining about 1~. combined alumina-
Zeo 49A in Example 2 and Zeo 49B in18.00 20.00 20.00
~xamples 3 and 4 (Huber)
Silica thickener (Syloid 244) 5.50
Sodium lauryl sulfate 1.20 1.20 1.20
Flavor 1.20 0.80 0.80
Although this invention ha been described with regard to
~llustrative examples, it wlll be apparent to one skllled in the
art that various modiflcations may b~ made ~hareto which fall
within its scope.
