U.S. patent application number 12/374099 was filed with the patent office on 2010-01-14 for method for preventing coloration of catechins and dentifrice composition.
This patent application is currently assigned to KAO Corporation. Invention is credited to Ikuhisa Ichimura, Hideaki Kubo, Koji Mine, Gen Nakauchi, Kazushi Oshino, Michiya Takagi, Satoshi Ueno.
Application Number | 20100008869 12/374099 |
Document ID | / |
Family ID | 38956737 |
Filed Date | 2010-01-14 |
United States Patent
Application |
20100008869 |
Kind Code |
A1 |
Takagi; Michiya ; et
al. |
January 14, 2010 |
METHOD FOR PREVENTING COLORATION OF CATECHINS AND DENTIFRICE
COMPOSITION
Abstract
The present invention relates to a method of suppressing
coloration of catechins, which contains adding, to catechins, a
water-soluble polymer forming a water-insoluble complex with
catechins, as well as hydrogel particles containing a
water-insoluble complex between catechins and a polymer forming a
water-insoluble complex with catechins. Further, the present
invention relates to a dentifrice composition containing hydrogel
particles containing catechins and a polymer forming a
water-insoluble complex with catechins, a binder and water.
Inventors: |
Takagi; Michiya; (Wakayama,
JP) ; Ueno; Satoshi; (Wakayama, JP) ; Mine;
Koji; (Wakayama, JP) ; Kubo; Hideaki;
(Wakayama, JP) ; Ichimura; Ikuhisa; (Tokyo,
JP) ; Nakauchi; Gen; (Tokyo, JP) ; Oshino;
Kazushi; (Tokyo, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, L.L.P.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
KAO Corporation
Chuo-ku Tokyo
JP
|
Family ID: |
38956737 |
Appl. No.: |
12/374099 |
Filed: |
June 26, 2007 |
PCT Filed: |
June 26, 2007 |
PCT NO: |
PCT/JP2007/063202 |
371 Date: |
March 24, 2009 |
Current U.S.
Class: |
424/55 ; 424/49;
424/56 |
Current CPC
Class: |
A61K 8/73 20130101; A61K
8/8182 20130101; A61K 2800/41 20130101; A61K 8/498 20130101; C08K
5/1545 20130101; A61K 8/347 20130101; C07D 311/62 20130101; A61K
31/353 20130101; A61K 8/731 20130101; A61P 17/18 20180101; A61P
31/04 20180101; A61Q 11/00 20130101; A61K 2800/54 20130101; A61K
2800/805 20130101; A61P 1/02 20180101; A61K 8/8176 20130101; A61K
8/042 20130101 |
Class at
Publication: |
424/55 ; 424/49;
424/56 |
International
Class: |
A61K 8/36 20060101
A61K008/36; A61K 8/30 20060101 A61K008/30; A61K 8/34 20060101
A61K008/34; A61P 1/02 20060101 A61P001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 21, 2006 |
JP |
2006199515 |
Jul 21, 2006 |
JP |
2006199516 |
Claims
1. A method of suppressing coloration of catechin, which comprises
adding, to the catechin, a water-soluble polymer (referred to
hereinafter as polymer A) forming a water-insoluble complex with
catechin.
2. The suppressing method according to claim 1, wherein the polymer
A is polyvinyl pyrrolidone.
3. The suppressing method according to claim 1 or 2, wherein the
weight-average molecular weight of the polymer A is 6000 to
3000000.
4. The suppressing method according to any one of claims 1 to 3,
wherein the polymer A is added in an amount of 1 to 4 times the
weight of the catechin.
5. Hydrogel particles comprising a water-insoluble complex of
catechin and the polymer A defined in claim 1.
6. The hydrogel particles according to claim 5, wherein the polymer
A is polyvinyl pyrrolidone.
7. A dentifrice composition comprising hydrogel particles
comprising catechin and the polymer A defined in claim 1, a binder
and water.
8. The dentifrice composition according to claim 7, wherein the
polymer A is polyvinyl pyrrolidone.
9. The dentifrice composition according to claim 7 or 8, wherein
the binder is at least one or more members selected from the group
consisting of sodium alginate, carboxymethylcellulose sodium,
carrageenan, xanthan gum, sodium polyacrylate, hydroxyethyl
cellulose, hydroxypropyl cellulose, pectin, tragacanth gum, gum
arabic, guar gum, karaya gum, locust bean gum, gellan gum, tamarind
gum, psyllium seed gum, polyvinyl alcohol, sodium chondroitin
sulfate, and a methoxy ethylene-maleic anhydride copolymer.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a method of suppressing
coloration of catechins and hydrogel particles containing a
water-insoluble complex of catechins. The present invention also
relates to a dentifrice composition containing catechins.
BACKGROUND OF THE INVENTION
[0002] Catechin, tannin, etc. are known as polyphenols contained in
tea leaves. Particularly, catechins are known to have various
physiological functions such as antioxidative action, antibacterial
action, blood cholesterol-level-rise suppressive action,
blood-pressure-rise suppressive action and blood-sugar-level-rise
inhibitory action. However, catechins themselves are potent
antioxidants and thus have a problem of undergoing oxidization and
polymerization during storage. Further, catechins have a problem of
discoloration upon oxidation and/or polymerization, thus
restricting the degree of freedom of their application to
pharmaceutical preparations. Accordingly, there is demand for a
method of suppressing oxidation and polymerization of
catechins.
[0003] JP-A 9-47654 relates to removal of polyphenols since the
presence of excessive polyphenols in products deteriorates the
commodity value, and is thus different in purpose from a method of
suppressing oxidation and polymerization of catechins.
[0004] JP-A 8-333380 discloses a process for producing tea saponin,
wherein an extract extracted with a water-containing lower alcohol
from hot-water extraction residues of tea leaves is treated with
water-insoluble polyvinyl pyrrolidone, thereby removing catechins
from the extract.
[0005] JP-A 1-218550 discloses a process for producing tannin-free
tea, which contains adding insoluble polyvinyl pyrrolidone to a
filtered extract extracted with hot water, etc. from anaerobically
treated tea leaves, and then filtering the extract.
[0006] It is known that dental caries and periodontitis are caused
by dental bacteria. Accordingly, dental caries and periodontitis
are prevented generally by killing dental bacteria or suppressing
their activity with a dental composition compounded with a
bacteriocide. Particularly with increasing natural-product
orientation in recent years, a naturally derived component is used
as the bacteriocide to avoid use of a chemically synthesized
substance. For example, a green tea extract and its components that
are tea polyphenol compounds (catechins etc.) are known to be
effective in suppressing proliferation of dental bacteria (for
example, JP-A 1-90124, JP-A 2-25413, JP-A 3-86814, etc.). These
literatures describe that since green tea extracts, etc. prevent
proliferation of Stereptococcus mutans that is a bacterium causing
dental caries and Porphyromonas gingivalis that is a bacterium
causing periodontitis, they can provide oral compositions effective
in preventing dental caries and periodontitis. However, the
polyphenol compounds (catechins etc.), when contacted with oxygen,
undergo oxidation and polymerization to discolor significantly, so
the discoloration with time of the oral composition itself
compounded therewith is inevitable. As the method of suppressing
such discoloration, for example, a method which contains
incorporating sugar alcohols having 4 to 5 carbon atoms (for
example, xylitol, erythritol etc.) into a polyphenol-containing
plant extract and sealing the product in individual
oxygen-impermeable bags is proposed (JP-A 2000-297022).
[0007] Meanwhile, as a method of incorporating various drugs,
easily denatured active ingredients, and the like, into oral
compositions, a method which contains stabilizing the ingredients
by capsulating them or including them in shells etc. is also
proposed (JP-A 61-225115, JP-A 1-275520, etc.).
SUMMARY OF THE INVENTION
[0008] The present invention provides a method of suppressing
coloration of catechins, which includes adding, to catechins, a
water-soluble polymer (referred to hereinafter as polymer A)
capable of forming a water-insoluble complex with catechins.
[0009] The present invention also provides hydrogel particles
containing a water-insoluble complex of catechins and polymer
A.
[0010] Further, the present invention provides a dentifrice
composition containing hydrogel particles containing catechin and a
water-soluble polymer forming a water-insoluble complex with
catechin, a binder and water.
[0011] The present invention provides use of a water-soluble
polymer forming a water-insoluble complex with catechin in
suppressing coloration of catechin. Further, the present invention
provides dentifrice use of a composition containing hydrogel
particles containing catechin and a water-soluble polymer forming a
water-insoluble complex with catechin, a binder and water.
DETAILED DESCRIPTION OF THE INVENTION
[0012] JP-A 9-47654 discloses a polyphenol adsorbent containing a
composite material containing an insoluble polyvinyl pyrrolidone
contained in a base material of regenerated cellulose
substance.
[0013] JP-A 8-333380 relates to removal of catechins, etc. that are
unnecessary substances other than the objective substance saponin
and is different in purpose from a method of suppressing oxidation
and polymerization of catechins.
[0014] JP-A 1-218550 relates to removal of tannin components in an
extract and is different in purpose from a method of suppressing
oxidation and polymerization of catechins.
[0015] In the conventional technique, techniques of adsorptive
removal of catechins by adsorbing the catechins onto polyvinyl
pyrrolidone are known, but a method of preventing discoloration of
catechins by suppressing oxidation and/or polymerization of the
catechins is not known.
[0016] The present invention provides a method of preventing
discoloration of catechins by suppressing coloration thereof, as
well as hydrogel particles of catechins whose coloration is
suppressed.
[0017] The inventors found that when hydrogel particles in which
catechins and a specific polymer forming a water-insoluble complex
with catechins have been included is contained in a dentifrice
composition, it is possible to obtain a dentifrice composition
excellent in sense of use wherein catechins are stably maintained
while gel-like particles are easily destroyed by brushing to permit
catechins to effectively act in the vicinity of the surfaces of
teeth and gum.
[0018] The present invention provides a dentifrice composition
excellent in sense of use wherein catechins are stably maintained,
and when used, the catechins act effectively on teeth and gum.
[0019] According to the present invention, catechins can be
stabilized by forming a water-insoluble complex with polymer A,
thereby suppressing coloration of the catechins.
[0020] The dentifrice composition of the present invention
maintains catechins stably, permits catechins to act effectively in
the vicinity of the surfaces of teeth and gum, to improve the state
of teeth and gum, and is excellent in sense of use.
[0021] In the present invention, catechins are non-polymer
catechins and include, for example, non-epicatechins such as
catechin, gallocatechin, catechingallate and gallocatechingallate,
and epicatechins such as epicatechin, epigallocatechin,
epicatechingallate and epigallocatechingallate. Catechins can be
obtained by concentration, purification, etc. of a green tea
extract extracted from tea leaves with hot water or a water-soluble
organic solvent. Alternatively, commercially available green tea
extract concentrates such as "Polyphenon" available from Mitsui
Norin Co., Ltd, "Thea-furan" from Ito En, Ltd., and "Sunphenon"
from Taiyo Kagaku Co., Ltd. can be used and subjected to regulation
of components, thereby yielding green tea extracts serving the
purpose of the present invention.
[0022] The polymer A used in the present invention is not
particularly limited as long as it is a water-soluble polymer
forming a water-insoluble complex with catechins.
[0023] The water-insoluble complex refers to a substance
precipitated from water as insoluble matter when an aqueous
solution of catechins is mixed with an aqueous solution of polymer
A. Precipitation of the water-insoluble complex can be confirmed by
turbidity of the mixture or by the presence of a peak originating
from the water-insoluble complex when the mixture is measured with
a laser diffraction/scattering particle size distribution
analyzer.
[0024] The polymer A includes polyvinyl pyrrolidone, polyvinyl
alcohol, and hydroxyethyl cellulose, among which polyvinyl
pyrrolidone (hereinafter abbreviated sometimes as PVP) is
preferable.
[0025] From the viewpoint of effectively suppressing coloration of
catechins, the weight-average molecular weight of polymer A is
preferably 6000 or more, more preferably 60000 or more, even more
preferably 400000 or more, even more preferably 1300000 or more.
The molecular weight is preferably 3000000 or less, more preferably
2000000 or less, from the viewpoint of obtaining a fine
water-insoluble complex by preventing the water-insoluble complex
from forming clumpy aggregates.
[0026] In the present invention, the weight-average molecular
weight of polymer A is a value determined for example by a laser
diffraction scattering method that is a general weight-average
molecular weight measuring method.
[0027] In the method of the present invention, the amount of
polymer A added is preferably 1 to 4 times, more preferably 1 to 3
times, even more preferably 1.2 to 2.2 times, the weight of the
catechins, from the viewpoint of effectively suppressing coloration
of catechins.
[0028] In the present invention, an aqueous solution of polymer A,
etc. are added to an aqueous solution of catechins, etc. and mixed
by means of a stirrer or the like, thereby forming a
water-insoluble complex to suppress coloration of the
catechins.
[0029] The hydrogel particles of the present invention contain a
water-insoluble complex of catechins and polymer A.
[0030] The "hydrogel" referred to in the present invention refers
to a water-containing swollen body of a water-insoluble polymer
(gel former) formed with water as a solvent. The gel former is
preferably a naturally occurring polymer compound and includes, for
example, seaweed extracts such as agar, .kappa.-carrageenan,
-carrageenan, .lamda.-carrageenan, furcelleran, alginate, and
propylene glycol alginate; plant seed viscous substances such as
guar gum, locust bean gum, tamarind seed polysaccharides, tara gum,
and quassia gum; plant fruit viscous substances such as pectin and
arabinogalactan; viscous substances produced by microorganisms,
such as xanthan gum, scleroglucan, pullulan, dextran, gellan gum
and curdlan; animal proteins such as gelatin, albumin and casein;
vegetable proteins such as soy protein and wheat protein; cellulose
and derivatives thereof, such as carboxymethyl cellulose, methyl
cellulose and microcrystalline cellulose; and starch and
derivatives thereof, such as starch phosphate and starch glycolate.
These gel formers may be used singly or as a mixture of two or more
thereof. .kappa.-Carrageenan, agar and gellan gum are preferable as
polymers that form physically collapse-prone, brittle gel
particles.
[0031] The dissolution temperature of agar in water is generally
75.degree. C. or more, mainly 75 to 90.degree. C., and when agar is
dissolved in water and then cooled, the gelling temperature is 30
to 45.degree. C.
[0032] The water-insoluble complex of catechins and polymer A is
dispersed in a continuous phase containing a gel former and water
and included in the hydrogel particles of the present invention. In
the water-insoluble complex, the amount of polymer A is preferably
1 to 4 times, more preferably 1 to 3 times, even more preferably
1.2 to 2.2 times, the weight of the catechins, from the viewpoint
of effectively suppressing the coloration of catechins.
[0033] The content of the water-insoluble complex of catechins and
polymer A in the hydrogel particles of the present invention is
preferably 12% by weight or less, more preferably 8% by weight or
less, even more preferably 6% by weight or less, from the viewpoint
of obtaining a fine water-insoluble complex by preventing the
water-insoluble complex from forming clumpy aggregates.
[0034] The content of the gel former in the hydrogel particles of
the present invention is preferably 0.25 to 5.0% by weight, more
preferably 0.5 to 4.0% by weight, even more preferably 1.0 to 3.0%
by weight, from the viewpoint of preventing the hydrogel particles
from collapsing upon incorporation into another preparation.
[0035] The hydrogel particles of the present invention may contain
water-soluble organic compounds such as sugars and polyhydric
alcohols and components such as a colorant, a preservative and a
water-soluble perfume in addition to the water-insoluble complex of
the present invention, the gel former, and water.
[0036] The sugars include glucose, galactose, fructose, mannose,
mannitol, saccharose, maltose, and lactose.
[0037] The polyhydric alcohols include glycerin, sorbitol, ethylene
glycol, polyethylene glycol, propylene glycol, polypropylene
glycol, and oligosaccharide.
[0038] From the viewpoint of outward appearance and productivity,
the average particle size of the hydrogel particles of the present
invention is preferably 5 to 10000 .mu.m, more preferably 100 to
10000 .mu.m, even more preferably 200 to 5000 .mu.m. The average
particle size of the hydrogel particles is expressed in weight
average particle size that is determined by subjecting 100 g of the
particles to wet classification in water by using sieves with
various mesh screens and then removing excess water therefrom with
filter paper (sieve method).
[0039] The shape of the hydrogel particle of the present invention
is not particularly limited, but is preferably the shape of a body
of revolution which is composed of a curved surface. The "body of
revolution which is composed of a curved surface" refers to a
three-dimensional body defined by rotating a closed plane formed by
a continuous curve and a virtual axis, but does not include a
three-dimensional body having a flat surface, such as a triangular
pyramid, circular cylinder, etc. In view of beautiful appearance,
the shape of the hydrogel particle is more preferably spherical or
elliptical.
[0040] The process for producing the hydrogel particles of the
present invention is not particularly limited. For example, a gel
former such as agar and polymer A are mixed with deionized water
and then dissolved sufficiently by heating at a temperature higher
than the dissolution temperature. An aqueous solution of catechins
is added to, and mixed with, the mixture and then subjected to a
general dropping, spraying or stirring method to yield hydrogel
particles.
[0041] The dropping method utilizes such a property of the mixture
as to form droplets by its surface or interfacial tension upon
ejection through an orifice. The droplets are cooled in a gaseous
phase (e.g., air) or liquid phase to solidify into hydrogel
particles. In view of producing hydrogel particles of uniform
particle diameter, the mixture ejected through an orifice is
preferably vibrated.
[0042] The spraying method uses a spray nozzle through which the
mixture is sprayed into a gaseous phase such that droplets of the
mixture are formed by the surface tension. The droplets are cooled
in the gaseous phase to solidify into hydrogel particles.
[0043] In the stirring method, the mixture is poured into a
solution which has a property of being substantially unmixable with
the mixture and which is regulated to a temperature equal to or
higher than the gelation temperature. The solution is stirred such
that the mixture is atomized by the shearing force of stirring,
whereby droplets are formed by the surface tension. The droplets
are cooled in a liquid which is substantially unmixable with the
mixture to solidify into hydrogel particles.
[0044] Whichever of the dropping method, spraying method, and
stirring method employed, the temperature of the mixture when
ejected, sprayed, or poured is preferably between the gelation
temperature and 100.degree. C. In view of readily producing
spherical particles with a beautiful appearance, the temperature of
the oil-in-water dispersion is preferably higher than the gelation
temperature by 10.degree. C. or more, more preferably higher than
the gelation temperature by 20.degree. C. or more. It should be
noted that the upper limit of this temperature is the boiling point
of water, i.e., 100.degree. C.
[0045] The hydrogel of the present invention can be incorporated
into cosmetics, detergents, bath agents, etc. The hydrogel can also
be incorporated into an oral composition, particularly a dentifrice
composition.
[0046] The hydrogel particles contained in the dentifrice
composition of the present invention contain the catechins and a
water-soluble polymer (hereinafter referred to polymer A) forming a
water-insoluble complex with the catechins.
[0047] In the description, the "hydrogel" refers to a
water-containing swollen body of a water-insoluble polymer (gel
former) with water as solvent, and the gel former is preferably a
naturally occurring polymer compound.
[0048] The content of catechins in the hydrogel particles of the
present invention is preferably 0.001 to 10% by mass, more
preferably 0.001 to 6% by mass, even more preferably 0.01 to 2% by
mass, from the viewpoint of the efficient action of catechins on
gums and of the stability of hydrogel particles. From the viewpoint
of effectively suppressing coloration of catechins, the content of
polymer A is preferably 1 to 4 times, more preferably 1 to 3 times,
even more preferably 1.2 to 2.2 times, the mass of the
catechins.
[0049] The content of the water-insoluble complex in the hydrogel
particles is preferably 12% by mass or less, more preferably 8% by
mass or less, even more preferably 6% by mass or less, from the
viewpoint of obtaining a fine water-insoluble complex by
suppressing the water-insoluble complex from forming clumpy
aggregates.
[0050] In the present invention, the gel former used in the
hydrogel particles is as described above.
[0051] The content of the gel former in the hydrogel particles of
the present invention is as described above, from the viewpoint of
preventing the hydrogel particles from collapsing upon
incorporation into a dentifrice composition.
[0052] The hydrogel particles of the present invention may contain
water-soluble organic compounds such as sugars and polyhydric
alcohols and components such as a colorant, a preservative and a
water-soluble perfume as described above, in addition to catechins,
polymer A, the gel former and water.
[0053] The process for producing the hydrogel particles of the
present invention is as described above.
[Dentifrice Composition]
[0054] The dentifrice composition of the present invention contains
the hydrogel particles described above, a binder and water.
[0055] The binder used in the present invention includes, for
example, sodium alginate, carboxymethylcellulose sodium,
carrageenan, xanthan gum, sodium polyacrylate, hydroxyethyl
cellulose, hydroxypropyl cellulose, pectin, tragacanth gum, gum
arabic, guar gum, karaya gum, locust bean gum, gellan gum, tamarind
gum, psyllium seed gum, polyvinyl alcohol, sodium chondroitin
sulfate, and a methoxy ethylene-maleic anhydride copolymer, among
which sodium alginate, carboxymethylcellulose sodium, carrageenan,
and xanthan gum are preferable.
[0056] Among these binders, sodium alginate is preferably one
having an intramolecular mannuronic acid/guluronic acid ratio (M/G
ratio) of 0.5 to 2.5, which is easily available commercially from
Kimica corporation and Dainippon Pharmaceutical Co., Ltd.
Carboxymethylcellulose sodium is preferably one having an
etherification degree of 0.6 to 2.5, which is easily available
commercially from Daicel Chemical Industries, Ltd. and Dai-ichi
Kogyo Seiyaku Co., Ltd., more preferably one having an
etherification degree of 0.8 to 1.5. Carrageenan that can be used
may be any of 3 isomers (.kappa.-, .lamda.- and -carrageenans) and
is easily and commercially available from Kelco Co., Ltd., MRC
Polysaccharide co., Ltd., Taiyo Kagaku Co., Ltd., etc., more
preferably - or .lamda.-carrageenan. Xanthan gum that can be used
is commercially available from Taiyo Kagaku Co., Ltd., Kelco Co.,
Ltd., Dainippon Pharmaceutical Co., Ltd. etc., and when used in
combination with carboxymethyl cellulose, is preferably xanthan gum
with low cellulase activity from which a small amount of
contaminating cellulase was removed.
[0057] The binders may be used singly or as a mixture of two or
more thereof, and the content of the binder in the composition is
preferably 0.1 to 3% by mass, more preferably 0.1 to 2% by mass,
even more preferably 0.2 to 1.2% by mass, from the viewpoint of
attaining storage stability, the viscosity of the composition, and
higher pleasant cooling sensation.
[0058] The content of the hydrogel particles in the dentifrice
composition of the present invention is preferably 0.01 to 15% by
mass, more preferably 0.1 to 10% by mass, even more preferably 1 to
5% by mass, from the stability of the dentifrice composition.
[0059] The amount of water in the dentifrice composition of the
present invention is preferably 1 to 50% by mass, more preferably 5
to 40% by mass, even more preferably 10 to 30% by mass, from the
viewpoint of attaining storage stability and higher pleasant
cooling sensation.
[0060] The dentifrice composition of the present invention can
further be compounded with powdery or granular erythritol having a
particle size of less than 355 .mu.m, from the viewpoint of
pleasant cooling sensation and taste. In the structure of
erythritol, there occurs 3 types of isomers that are L-erythritol,
D-erythritol and meso-erythritol, and any of these structures can
be used in the present invention. Erythritol that can be used may
be an ordinarily available one and includes, for example,
crystalline erythritol obtained by fermenting glucose and
re-crystallizing the product. The crystalline erythritol is
available as commercial products from Nikken Chemicals Co., Ltd.,
Mitsubishi-Kagaku Foods Corporation, Celestare, etc. Erythritol
having a large particle size may be used after regulation of
particle size by pulverization. For pulverization of erythritol, a
roller mill, a hammer mill, a high-speed grinder or a pulverizer is
generally used, among which a high-speed grinder or a hammer mill
excellent in production efficiency with easy regulation of particle
size is preferably used in pulverization.
[0061] The particle size of erythritol is preferably 45 .mu.m or
more to less than 355 .mu.m, more preferably 53 .mu.m or more to
less than 300 .mu.m, even more preferably 75 .mu.m or more to less
than 250 .mu.m, from the viewpoint of long-lasting pleasant cooling
sensation in the mouth. Erythritol having a particle size of 45
.mu.m or more is preferable because the pleasant cooling sensation
is long-lasting without instantaneous dissolution in the mouth.
Erythritol having a particle size of less than 355 .mu.m is readily
dissolved in the mouth and can demonstrate a pleasant cooling
sensation.
[0062] The particle size of erythritol is measured in the following
manner. [0063] Sieve: JIS standard sieve .phi.75 mm [0064] Mesh
sizes: Under sieves having mesh sizes of 500 .mu.m, 355 .mu.m, 250
.mu.m, 180 .mu.m, 125 .mu.m, 90 .mu.m and 45 .mu.m in the direction
of from upper to lower stages, respectively, a receiver is placed.
[0065] Shaker: Micro-electromagnetic shaker M-2 (Tsutsui Science
Instrument Co., Ltd.) [0066] Method: 15 g of a sample is placed on
a 500-.mu.m sieve and then classified for 5minutes with the
electromagnetic shaker. The total amount of erythritol present on
sieves having mesh sizes of 250 .mu.m, 180 .mu.m, 125 .mu.m, 90
.mu.m and 45 .mu.m is determined as the amount of erythritol having
a particle size of 45 .mu.m or more to less than 355 .mu.m.
[0067] The amount of erythritol incorporated into the dentifrice
composition of the present invention is preferably 15 to 60% by
mass, more preferably 20 to 55% by mass, even more preferably 25 to
50% by mass, even more preferably 30 to 50% by mass, from the
viewpoint of a pleasant cooling sensation.
[0068] Erythritol is desirably dispersed in a powdery state in the
dentifrice composition. For this state, erythritol is introduced
preferably in the form of powder in the final stage of production.
By using such a method, erythritol is hardly dissolved in water and
can be present in a powdery state in the dentifrice
composition.
[0069] The dentifrice composition of the present invention may
further contain an abrasive. The abrasive includes not only silica
such as precipitated silica, silica gel, aluminosilicate,
silconosilicate, and gluconosilicate but also calcium carbonate,
calcium hydrogen phosphate, calcium pyrophosphate, aluminum
hydroxide, alumina, magnesium carbonate, and magnesium phosphate.
The content of the abrasive in the dentifrice composition of the
present invention is preferably 0 to 15% by mass, more preferably 0
to 12% by mass.
[0070] Other compounding ingredients usable in the oral
composition, for example antioxidants, wetting agents, medicinal
components, foaming agents, preservatives, flavorings, sweetening
agents, pH adjusters and the like may be incorporated into the
dentifrice composition of the present invention in such a range
that the purpose of the present invention is not hindered.
[0071] The antioxidants include components having antioxidative
potency or reducing power and usable in oral compositions, for
example, L-ascorbic acid and salts thereof, erythorbic acid and
salts thereof, .alpha.-tocopherol acetic acid,
dl-.alpha.-tocopherol, rosemary extract, stevia extract, sunflower
seed extract, propyl gallate, dibutyl hydroxy toluene, butyl
hydroxy anisole, L-cysteine hydrochloride, phytic acid,
hydroquinone and glycosides thereof, nordihydroguaiuretic acid,
ascorbic higher fatty acid esters (laurate, stearate, isostearate,
palmitate etc.) and guaiac gum. Salts of L-ascorbic acid,
erythorbic acid or .alpha.-tocopherol acetic acid include sodium
salts, calcium salts, ferrous salts and palmitate salt. These
antioxidants may be used singly or as a mixture of two or more
selected antioxidants. The content of the antioxidant in the
dentifrice composition of the present invention is preferably
0.0005 to 50% by mass, more preferably 0.001 to 20% by mass, even
more preferably 0.01 to 5% by mass, from the viewpoint of
suppressing a change in color of outside.
[0072] The wetting agents include, for example, glycerin, sorbitol,
polyethylene glycol, propylene glycol, ethylene glycol,
1,3-butylene glycol, polypropylene glycol, xylitol, erythritol,
maltitol and lactitol, and a combination of one or two or more
thereof may be incorporated into the composition. The content of
these wetting agents in the dentifrice composition of the present
invention is preferably 40 to 95% by mass, more preferably 60 to
80% by mass, from the viewpoint of securing transparency.
[0073] The dentifrice composition of the present invention can be
formed in a usual manner into a paste dentifrice composition, a
liquid dentifrice composition, a gel-like dentifrice composition,
etc. depending on its intended use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0074] FIG. 1 is a graph showing the relationship between
brightness difference obtained in Test Example 1 and the degree of
elution of catechins in Test Example 2. FIG. 2 is a graph showing
the effect of dentifrice composition A on the gum. FIG. 3 is a
graph showing the effect of dentifrice composition B on the
gum.
EXAMPLES
[0075] The following examples further describe and demonstrate
embodiments of the present invention. The examples are given solely
for the purpose of illustration and are not to be construed as
limitations of the present invention.
[0076] In the following examples, the average particle size of
hydrogel particles was measured by the sieve method described
above.
Example 1
[0077] An aqueous solution (85.degree. C.) prepared by dissolving
20 g of polyvinyl pyrrolidone (K-15, weight-average molecular
weight 8000, manufactured by ISP) in 330 g of deionized water was
mixed by a homomixer (8000 r/min, 1 minute) with an aqueous
solution (20.degree. C.) prepared by dissolving 10 g of catechin
powder (Sunphenon 100S manufactured by Taiyo Kagaku Co., Ltd.) in
140 g of deionized water, to yield an aqueous catechin/PVP complex
dispersion with the composition in Table 1.
TABLE-US-00001 TABLE 1 % by weight Polyvinyl pyrrolidone (K-15) 4.0
Catechin (Sunphenon 100S) 2.0 Deionized water 94.0
Example 2
[0078] An aqueous solution (85.degree. C.) prepared by dissolving
12.5 g of agar (UP-37 manufactured by Ina Food Industry Co., Ltd.),
4 g of PVP (K-30, weight-average molecular weight of 60000,
manufactured by ISP) and 12 g of PVP (K-90, weight-average
molecular weight of 1300000, manufactured by ISP) in 321.5 g of
deionized water was mixed by a homomixer (8000 r/min, 1 minute)
with an aqueous solution (20.degree. C.) prepared by dissolving 10
g of catechin powder (Sunphenon 100S) in 140 g of deionized water,
and then sprayed into a gaseous phase to yield catechin/PVP
complex-included hydrogel particles with the composition in Table
2. The average particle size of the hydrogel particles was 195
.mu.m.
TABLE-US-00002 TABLE 2 % by weight Agar(UP-37) 2.5 Polyvinyl
pyrrolidone (K-30) 0.8 Polyvinyl pyrrolidone (K-90) 2.4 Catechin
(Sunphenon 100S) 2.0 Deionized water 92.3
Comparative Example 1
[0079] 10 g of catechin powder (Sunphenon 100S) was dissolved in
490 g of deionized water to prepare a 2 wt % aqueous catechin
solution.
Test Example 1
[0080] The aqueous catechin/PVP complex dispersion obtained in
Example 1, the catechin/PVP complex-included hydrogel particles in
Example 2 and the aqueous catechin solution in Comparative Example
1 were used to prepare preparations with the compositions shown in
Table 3. The resulting preparations were stored at 50.degree. C.
for 1 month and measured for brightness difference before and after
storage, and by this brightness difference, the degree of
discoloration was evaluated. The results are shown in Table 3.
<Method of Measuring the Brightness Difference>
[0081] A transparent case with an internal size of 3 cm.times.3
cm.times.1 cm (PS CASE No. 1, manufactured by AS ONE) was filled up
with the preparation after storage. Together with the case, nine
points in KODAK GRAY SCALE, that is, A, 2, 4, 6, 8, 10, 12, 14 and
B (assumed to be color densities 1 to 9, respectively) as color
density standards, and CASMATCH (manufactured by Dai Nippon
Printing Co., Ltd.), were photographed on a white paper in the same
visual field. The photographing was conducted at a constant shutter
speed, stop and focal distance under uniform lighting with a ring
light. The photographed image was color-corrected with CASMATCH in
an ADOBE PHOTOSHOP, then the brightness (brightness in HSB color
model) in a site to be measured was quantified with WINROOF (Mitani
Corporation), and the difference between the brightness of the
sample stored at 50.degree. C. for 1 month and the initial
brightness was determined as the degree of discoloration by using
the following equation:
Degree of discoloration=(brightness after storage at 50.degree. C.
for 1 month)-(initial brightness)
TABLE-US-00003 TABLE 3 Test No. 1-1 1-2 1-3 Composition
Polyethylene glycol 600*.sup.1 4.0 4.0 4.0 (% by Sodium fluoride
0.2 0.2 0.2 weight) Sorbit Liquid(70% aqueous solution) 40.0 40.0
40.0 Silicic anhydride 15.0 15.0 15.0 Sodium lauryl sulfate 1.0 1.0
1.0 Carboxymethylcellulose sodium*.sup.2 0.5 0.5 0.5 DL-malic acid
0.1 0.1 0.1 Ascorbic acid 0.1 0.1 0.1 Anhydrous sodium
pyrophosphate 0.2 0.2 0.2 Saccharine sodium 0.1 0.1 0.1 Perfume 1.0
1.0 1.0 Colorant trace amount trace amount trace amount Aqueous
catechin/PVP complex dispersion in Example 1 3.0 Catechin/PVP
complex-including hydrogel particles 3.0 in Example 2 Aqueous
catechin solution in Comparative example 1 3.0 Deionized water
Balance Balance Balance Brightness difference 46.9 1.2 63.4
*.sup.1Polyethylene glycol with an average molecular weight of 600
*.sup.2CMC<1150> manufactured by Daicel Chemical Industries,
Ltd.
[0082] As is evident from Table 3, discoloration is more suppressed
when the aqueous catechin/PVP complex dispersion in Example 1 or
the catechin/PVP complex-included hydrogel particles in Example 2
was incorporated than when the aqueous catechin solution in
Comparative Example 1 was incorporated, and particularly coloration
is significantly suppressed when the hydrogel particles in Example
2 is incorporated. Accordingly, it can be seen that in the aqueous
catechin/PVP complex dispersion in Example 1 or in the catechin/PVP
complex-included hydrogel particles in Example 2, catechins are
suppressed from discoloring by oxidation and/or polymerization,
thereby stabilizing catechins.
Test Example 2
[0083] The aqueous catechin/PVP complex dispersion obtained in
Example 1, the catechin/PVP complex-included hydrogel particles in
Example 2, and the aqueous catechin solution in Comparative Example
1 were used to prepare aqueous sodium lauryl sulfate solutions with
the compositions shown in Table 4. The amount of catechin eluted
into the aqueous sodium lauryl sulfate solution after 1 month of
storage at room temperature was quantified by the following method
to determine the degree of elution. The results are shown in Table
4.
<Method of Quantifying the Concentration of Catechin in the
Aqueous Sodium Lauryl Sulfate Solution>
[0084] 1.0 g of the sample (aqueous sodium lauryl sulfate solution)
is taken and then mixed with 19.0 g phosphate buffer and 5.0 g iron
tartrate reagent. The absorbance of the prepared mixture at 540 nm
is measured. Separately, aqueous catechin solutions of known
concentration are prepared from catechin powder (Sunphenon 100S)
and used to prepare a calibration curve. The concentration of
catechin in the sample is determined from the calibration curve to
determine the degree of elution. The iron tartrate reagent is
prepared by dissolving 100 mg ferrous sulfate (7H.sub.2O) and 500
mg sodium potassium tartrate in water to prepare a 100 ml solution.
The phosphate buffer is prepared by mixing M/15 disodium
hydrogenphosphate and M/15 dipotassium hydrogenphosphate at a ratio
of 84:16.
TABLE-US-00004 TABLE 4 Test No. 2-1 2-2 2-3 Composition Deionized
water 49.0 49.0 49.0 of aqueous Ethanol 10.0 10.0 10.0 solution
Sodium laurate 1.0 1.0 1.0 (% by weight) Aqueous catechin/PVP
complex 40.0 dispersion in Example 1 Catechin/PVP complex-including
40.0 hydrogel particles in Example 2 Aqueous catechin solution in
40.0 Comparative example 1 Degree of elution (%) 33.0 8.5 100
[0085] The measurement results of brightness difference in Test
Example 1 are plotted against the degree of elution of catechin
obtained in Test Example 2, to show the relationship between the
degree of elution and the brightness difference in FIG. 1. From
FIG. 1, it was found that as the degree of elution into the aqueous
sodium lauryl sulfate solution decreases, the brightness difference
decreases. That is, it was found that the effect of suppressing
discoloration increases with a decreasing degree of catechin into
the aqueous sodium lauryl sulfate solution when the PVP/catechin
complex is mixed with the aqueous sodium lauryl sulfate solution,
and the oxidation and/or polymerization of catechin can be
suppressed and the stability of catechin is high.
Example 3
[0086] An aqueous solution (85.degree. C.) prepared by dissolving
12.5 g of agar (UP-37) and 10.0 g of PVP (K-30, weight-average
molecular weight of 60000) in 327.5 g of deionized water was mixed
by a homomixer (8000 r/min, 1 minute) with an aqueous solution
(20.degree. C.) prepared by dissolving 5 g of catechin powder
(Sunphenon 100S) in 145 g of deionized water, and then sprayed into
a gaseous phase to yield catechin/PVP complex-included hydrogel
particles having the composition and average particle size shown in
Table 5.
Example 4
[0087] Catechin/PVP complex-included hydrogel particles having the
composition and average particle size shown in Table 5 were
obtained in the same manner as in Example 3 except that 10.0 g of
PVP (K-60, weight-average molecular weight of 400000, manufactured
by ISP) was used.
Example 5
[0088] Catechin/PVP complex-included hydrogel particles having the
composition and average particle size shown in Table 5 were
obtained in the same manner as in Example 3 except that 10.0 g of
PVP (K-90, weight-average molecular weight of 1300000) was
used.
TABLE-US-00005 TABLE 5 Exam- Exam- Exam- ple 3 ple 4 ple 5 Hydrogel
Agar(UP-37) 2.5 2.5 2.5 particles Polyvinyl pyrrolidone(K-30) 2.0
(% by Polyvinyl pyrrolidone(K-60) 2.0 weight) Polyvinyl
pyrrolidone(K-90) 2.0 Catechin (Sunphenon100S) 1.0 1.0 1.0
Deionized water 94.5 94.5 94.5 Average particle diameter (.mu.m)
210 200 205
Test Example 3
[0089] The catechin/PVP complex-included hydrogel particles
prepared in Examples 3 to 5 were used to prepare aqueous sodium
lauryl sulfate solutions with the compositions shown in Table 6.
The amount of catechin eluted into the sodium lauryl sulfate
solution after 10 days of storage at room temperature was
quantified in the same manner as in Test Example 2 to determine the
degree of elution. The results are shown in Table 6.
TABLE-US-00006 TABLE 6 Test No. 3-1 3-2 3-3 Composition Deionized
water 49.0 49.0 49.0 of aqueous Ethanol 10.0 10.0 10.0 solution
Sodium laurate 1.0 1.0 1.0 (% by weight) Catechin/PVP
complex-including 40.0 hydrogel particles in Example 3 Catechin/PVP
complex-including 40.0 hydrogel particles in Example 4 Catechin/PVP
complex-including 40.0 hydrogel particles in Example 5 Degree of
elution (%) 46.0 37.0 28.5
[0090] From the results in Table 6, it can be seen that as the
molecular weight of PVP in the hydrogel particles increases, the
degree of elution into the aqueous sodium lauryl sulfate can be
reduced. When the relationship with the brightness difference in
Test Example 1 is utilized, it was found that the effect of
suppressing discoloration increases with an increasing molecular
weight of PVP, the oxidation and/or polymerization of catechin can
be suppressed, and the stability of catechin is high.
Example 6
[0091] An aqueous solution (85.degree. C.) prepared by dissolving
12.5 g of agar (UP-37), 3.0 g of PVP (K-30) and 9.0 g of PVP (K-90)
in 325.5 g of deionized water was mixed by a homomixer (8000 r/min,
1 minute) with an aqueous solution (20.degree. C.) prepared by
dissolving 10 g catechin powder (Sunphenon 100S) in 140 g of
deionized water, and then sprayed into a gaseous phase to yield
catechin/PVP complex-included hydrogel particles having the
composition and average particle size shown in Table 7.
Example 7
[0092] An aqueous solution (85.degree. C.) prepared by dissolving
12.5 g of agar (UP-37), 3.5 g of PVP (K-30) and 10.5 g of PVP
(K-90) in 323.5 g of deionized water was mixed by a homomixer (8000
r/min, 1 minute) with an aqueous solution (20.degree. C.) prepared
by dissolving 10 g of catechin powder (Sunphenon 100S) in 140 g of
deionized water, and then sprayed into a gaseous phase to yield
catechin/PVP complex-included hydrogel particles having the
composition and average particle size shown in Table 7.
Example 8
[0093] An aqueous solution (85.degree. C.) prepared by dissolving
12.5 g of agar (UP-37), 5.0 g of PVP (K-30) and 15.0 g of PVP
(K-90) in 323.5 g of deionized water was mixed by a homomixer (8000
r/min, 1 minute) with an aqueous solution (20.degree. C.) prepared
by dissolving 10 g of catechin powder (Sunphenon 100S) in 140 g of
deionized water, and then sprayed into a gaseous phase to yield
catechin/PVP complex-included hydrogel particles having the
composition and average particle size shown in Table 7.
Example 9
[0094] An aqueous solution (85.degree. C.) prepared by dissolving
12.5 g of agar (UP-37), 5.5 g of PVP (K-30) and 16.5 g of PVP
(K-90) in 323.5 g of deionized water was mixed by a homomixer (8000
r/min, 1 minute) with an aqueous solution (20.degree. C.) prepared
by dissolving 10 g of catechin powder (Sunphenon 100S) in 140 g of
deionized water, and then sprayed into a gaseous phase to yield
catechin/PVP complex-included hydrogel particles having the
composition and average particle size shown in Table 7.
TABLE-US-00007 TABLE 7 Example 6 Example 7 Example 8 Example 9
Hydrogel particles Agar(UP-37) 2.5 2.5 2.5 2.5 (% by weight)
Polyvinyl pyrrolidone (K-30) 0.6 0.7 1.0 1.1 Polyvinyl pyrrolidone
(K-90) 1.8 2.1 3.0 3.3 Catechin (Sunphenon 100S) 2.0 2.0 2.0 2.0
Deionized water 93.1 92.7 91.5 91.1 Weight ratio of catehin/PVP
1/1.2 1/1.4 1/2.0 1/2.2 Average particle diameter (.mu.m) 215 230
210 220
Test Example 4
[0095] The catechin/PVP complex-included hydrogel particles
prepared in Example 2 and Examples 6 to 9 were used to prepare
aqueous sodium lauryl sulfate solutions with the compositions shown
in Table 8. The amount of catechin eluted into the aqueous sodium
lauryl sulfate solution after 20 days of storage at room
temperature was quantified in the same manner as in Test Example 2
to determine the degree of elution. The results are shown in Table
8.
TABLE-US-00008 TABLE 8 Test No. 4-1 4-2 4-3 4-4 4-5 Composition of
Deionized water 49.0 49.0 49.0 49.0 49.0 aqueous solution Ethanol
10.0 10.0 10.0 10.0 10.0 (% by weight) Sodium laurate 1.0 1.0 1.0
1.0 1.0 Catechin/PVP complex-including hydrogel particles in
Example 2 40.0 Catechin/PVP complex-including hydrogel particles in
Example 6 40.0 Catechin/PVP complex-including hydrogel particles in
Example 7 40.0 Catechin/PVP complex-including hydrogel particles in
Example 8 40.0 Catechin/PVP complex-including hydrogel particles in
Example 9 40.0 Catechin/PVP weight ratio in hydrogel particles
1/1.6 1/1.2 1/1.4 1/2.0 1/2.2 Degree of elution (%) 8.5 14.0 10.0
22.0 30.0
[0096] As is evident from Table 8, it can be seen that when
hydrogel particles with a catechin/PVP weight ratio of 1.0/1.6 was
incorporated, the degree of elution is the minimum. That is, it was
found that when the catechin/PVP weight ratio in the hydrogel
particles is 1.0/1.6, the effect of suppressing discoloration is
the highest, the coloration of catechin can be suppressed and the
stability of catechin is high.
[0097] The dentifrice composition of the present invention will be
described by reference to the following examples.
[0098] In the Examples, "%" refers to "% by mass" unless otherwise
specified.
Production Example 1
[0099] An aqueous solution (85.degree. C.) prepared by dissolving
15 g of agar (UP-37 manufactured by Ina Food Industry Co., Ltd.)
and 16 g of PVP (K-90, weight-average molecular weight of 1300000,
manufactured by ISP) in 319 g of deionized water was mixed by a
homomixer (8000 r/min, 1 minute) with an aqueous solution
(20.degree. C.) prepared by dissolving 10 g of tea extract
(Sunphenon 100S, catechin content 60 to 70%, manufactured by Taiyo
Kagaku Co., Ltd.) in 140 g of deionized water, and then sprayed
into a gaseous phase to yield hydrogel particles with the
composition shown in Table 9. The average particle size of the
hydrogel particles was 200 .mu.m.
TABLE-US-00009 TABLE 9 Composition of hydrogel particles Compound
name Proportion (%) Tea extract 2 (catechin content 60 to 70%) Agar
3 PVP 3.2 Purified water Balance Total 100
Example 10
[0100] The hydrogel particles obtained in Production Example 1 or
the tea extract (Sunphenon 100S, catechin content 60 to 70%,
manufactured by Taiyo Kagaku Co., Ltd.) was used to prepare
dentifrice composition A (Comparative Product) and dentifrice
composition B (Invented Product) having the compositions shown in
Table 10. The resulting dentifrice compositions A and B were
evaluated for their discoloration and taste by the following
methods. The results are shown in Table 10. The effect on the gum
was also examined by the following method. The results are shown in
FIGS. 2 and 3.
<Method of Evaluating Discoloration>
[0101] The resulting dentifrice composition was filled in a
container, stored at 50.degree. C. for 1 month, and measured for
brightness difference after storage by the following method, and by
this brightness difference, the degree of discoloration was
evaluated. A transparent case with an internal size of 3 cm.times.3
cm.times.1 cm (PS CASE No. 1, manufactured by AS ONE) was filled up
with the dentifrice preparation after storage. Together with the
case, nine points in KODAK GRAY SCALE, that is, A, 2, 4, 6, 8, 10,
12, 14 and B (assumed to be color densities 1 to 9, respectively)
as color density standards, and CASMATCH (manufactured by Dai
Nippon Printing Co., Ltd.), were photographed on white paper in the
same visual field. The photographing was conducted at a constant
shutter speed, stop and focal distance under uniform lighting with
a ring light. The photographed image was color-corrected with
CASMATCH in an ADOBE PHOTOSHOP, then the brightness (brightness in
HSB color model) in a site to be measured was quantified with
WINROOF (Mitani Corporation), and the difference between the
brightness of the sample stored at 50.degree. C. for 1 month and
the (initial) brightness just after production was determined as
the degree of discoloration by using the following equation
(I):
Degree of discoloration=(brightness after storage at 50.degree. C.
for 1 month)-(initial brightness) (I)
<Method of Evaluating Taste>
[0102] Flavors of the dentifrice compositions A and B were
evaluated by a panel of 9 experts under the following 3 criteria,
and the results are shown in mean value.
Evaluation Criteria
[0103] 1: Not astringent.
[0104] 2: Not very astringent.
[0105] 3: Astringent.
<Effect on the Gum>
[0106] The dentifrice compositions A and B were used respectively
for 1 week by 9 male and female persons in their twenties to
fifties and examined for change in BOP (Bleeding On Probing) before
and after use. BOP (Bleeding On Probing) refers to a state of
bleeding occurring when a WHO probe is removed after insertion into
the bottom of the gum in a periodontal pocket (gap between tooth
and gum). Bleeding does not occur when the gum is healthy, while
bleeding easily occurs when there is inflammation in the pocket and
the bottom of the gum. That is, the gum is in a worse state as the
number of BOP sites increases.
TABLE-US-00010 TABLE 10 Dentifrice Dentifrice composition A
composition B Composition Polyethylene glycol 600 *.sup.1 4 4 (%)
Sodium fluorate 0.2 0.2 Sorbit liquid(70% aqueous solution) 40 40
Abrasive silica *.sup.2 10 10 Thickening silica *.sup.3 5 5 Sodium
lauryl sulfate 1 1 Carboxymethylcellulose sodium *.sup.4 0.5 0.5
DL-malic acid 0.1 0.1 Ascorbic acid 0.1 0.1 Anhydrous sodium
pyrophosphate 0.2 0.2 Saccharine sodium 0.1 0.1 Perfume 1 1
Colorant Trace amount Trace amount Tea extrat *.sup.5 0.06 --
Hydrogel particles in Production example 1 -- 3 Purified water
Balance Balance Total 100 100 Results of Degree of discoloration
63.4 1.2 evaluation Taste 2.5 1.67 *.sup.1 Polyethylene glycol with
an average molecular weight of 600 *.sup.2 Solbocyl AC43 (Ineos
Silicas Limited) *.sup.3 Solbocyl TC15 (Ineos Silicas Limited)
*.sup.4 CMC<1150> manufactured by Daicel Chemical Industries,
Ltd. *.sup.5 Sunphenon 100S, catechin content 60 to 70%,
manufactured by Taiyo Kagaku Co., Ltd.
[0107] As is evident from Table 10, the dentifrice composition B
containing the catechin-included hydrogel particles of the present
invention, as compared with the dentifrice composition A containing
catechins as they are without being included, was significantly
prevented from discoloring and was superior in taste.
[0108] As is evident from FIGS. 2 and 3, it can be seen that when
the dentifrice composition A is used, the value of BOP is
substantially not changed in 1 week, and the state of gum is not
improved, while when the dentifrice composition B is used, the
value of BOP is lowered in 1 week, and the state of gum is
improved. It is estimated that catechins formed into hydrogel
particles are useful in improving an effect of ameliorating
gingivitis.
Example 11
[0109] The hydrogel particles obtained in Production Example 1 or
the tea extract (Sunphenon 100S, catechin content 60 to 70%,
manufactured by Taiyo Kagaku Co., Ltd.) was used to prepare
dentifrice composition C (Comparative Product) and dentifrice
composition D (Invented Product) having the compositions shown in
Table 11. The resulting dentifrice compositions C and D were
evaluated for their discoloration and taste by the same methods as
in Example 10. The results are shown in Table 11.
TABLE-US-00011 TABLE 11 Dentifrice Dentifrice composition C
composition D Composition Polyethylene glycol 600 *.sup.1 4 4 (%)
Sodium fluoride 0.2 0.2 Sorbit liquid (70% aqueous solution) 21 21
Erythritol *.sup.6 23 23 Abrasive silica *.sup.2 10 10 Thickening
silica *.sup.3 5 5 Sodium lauryl sulfate 1 1 Carboxymethylcellulose
sodium *.sup.4 0.5 0.5 DL-malic acid 0.1 0.1 Ascorbic acid 0.1 0.1
Anhydrous sodium pyrophosphate 0.2 0.2 Saccharine sodium 0.1 0.1
Perfume 1 1 Colorant Trace amount Trace amount Tea extract *.sup.5
0.06 -- Hydrogel particles in Production example 1 -- 3 Purified
water Balance Balance Total 100 100 Results of Degree of
discoloration 92.7 10.7 evaluation Taste 1.78 1.11 *.sup.1 to
*.sup.5 are the same as in Table 10. *.sup.6 Erythritol having a
particle-size distribution in which particles of less than 45 .mu.m
in particle size are 13% by mass, those of 45 .mu.m or more to less
than 250 .mu.m are 82% by mass, and those of 250 .mu.m or more to
less than 355 .mu.m are 5% by mass.
[0110] As is evident from Table 11, the dentifrice composition D
containing the catechin-included hydrogel particles of the present
invention, as compared with the dentifrice composition C containing
catechins as they are without being included, was significantly
prevented from discoloring and was superior in taste.
* * * * *