Oral composition containing a polyglycerol fatty acid monoester and an N-acylamino acid or a salt thereof

An oral composition containing, as a surfactant, polyglycerol fatty acid monoester having a polymerization degree of glycerol of 6 or more and 10 to 20 carbon atoms in the fatty acid moiety. An N-acylamino acid or a salt thereof may be contained in this oral composition.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an oral composition containing 
polyglycerol fatty acid monoester. 
2. Description of the Related Art 
Conventional oral compositions generally contain surfactants to increase 
the cleanability thereof, and the characteristics additionally required 
for surfactants to be used in oral compositions are an excellent 
formability, a good overall sensation in mouth (e.g., surfactants must not 
have unpleasant taste such as bitter taste, astringency, or unpleasant 
odor), and a high safety factor. Furthermore, a very important 
characteristic required for surfactants to be used in oral compositions is 
that the surfactants are suitable for long term storage, in that 
denaturing (e.g., discoloration and liquid separation) does not occur. 
Anionic surfactants and nonionic surfactants are used as a surfactant in 
conventional oral compositions, and of these surfactants, anionic 
surfactants such as sodium lauryl sulfate are widely used in oral 
compositions because of their excellent formability. However, sodium laury 
sulfate has an inferior juice effect (i.e., the effect not for changing 
the taste of a juice after using oral compositions) and are 
disadvantageous in that the stable formulation of, for example, enzymes, 
therein is difficult. On the other hand, although nonionic surfactants are 
superior to anionic surfactants in, for example, safety, stabilization of 
effective components, and juice effect, most nonionic surfactants 
conventionally used in oral compositions are disadvantageous in that they 
have a poor foamability, taste, and odor. For example, sucrose laurate 
(ester) and sucrose myristate (ester) have a relatively good foamability, 
but have a strong bitter taste. Furthermore, when sucrose fatty acid 
esters are formulated into dentifrices, the dentifrices are discolored 
yellow and liquid separation occurs when they are stored for a long term 
or at an elevated temperature (e.g., at a store in the summer), and thus, 
are not practical. 
SUMMARY OF THE INVENTION 
Accordingly, the objects of the present invention are to eliminate the 
above-mentioned disadvantages of the prior art and to provide an oral 
composition containing a surfactant having a good overall sensation in 
mouth (e.g., foamability, taste, and odor), an excellent juice effect, a 
good stability, no substantial discoloration even when stored at an 
elevated temperature for a long time, and a high safety factor when used. 
Other objects and advantages of the present invention will be apparent from 
the following description. 
In accordance with the present invention, there is provided an aqueous oral 
composition containing a polyglycerol fatty acid monoester having a 
polymerization degree of glycerol of 6 or more and having 10 to 20 carbon 
atoms in the fatty acid moiety. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The present inventors have found that polyglycerol fatty acid monoesters 
having a polymerization degree of glycerol of 6 or more and having 10 to 
20 carbon atoms in the fatty acid moiety are useful surfactants, having a 
high cleanability, good foamability, high safety factor, cause little 
irritation of the mucos membrane, can very stably formulate, for example, 
an enzyme, have an excellent juice effect, and an excellent overall 
sensation in the mouth because of a remarkably reduction of the bitter 
taste and astringency thereof when compared to sucrose fatty acid esters, 
no substantial discoloration when stored at an elevated temperature for a 
long time, and a good storage stability. Therefore, when these 
polyglycerol fatty acid monesters are formulated into oral compositions, 
the overall sensation in the mouth and the stability thereof are 
excellent, and the effective components are stably retained in the 
compositions. Furthermore, when N-acylamino acids or the salts thereof are 
used, in combination with the polyglycerol fatty acid monesters, in the 
oral compositions, the formability of the polyglycerol fatty acid 
monoesters is further increased. 
According to the present invention, polyglycerol fatty acid monoesters are 
formulated into oral compositions such as tooth paste, powder dentifrice, 
liquid dentifrice, and wet dentrifrice, or a mouth wash. 
The polyglycerol fatty acid monoesters usable in the present invention may 
be produced from glycerol and fatty acids. The polyglycerol fatty acid 
monoesters preferably have a glycerol polymerization degree of 6 or more, 
more preferably 6 to 10. When the polymerization degree of glycerol is 
less than 6, the foamability is poor and the monoester is not suitable for 
use in an oral composition. 
The fatty acids for the polyglycerol fatty acid monoesters may have linear 
or branched acyl groups, and the carbon numbers of the acyl groups should 
be 10 to 20, preferably 12 to 18. When the carbon number of the acyl 
groups is less than 10 or more than 20, the characteristics required as 
surfactants for oral compositions, such as the foamability and taste, 
become poor and, therefore, the objects of the present invention cannot be 
attained. Typical examples of the acyl groups are saturated or unsaturated 
acyl groups such as lauroyl, myristoyl, stearoyl, and oleoyl, and these 
may be used alone or any mixture thereof. 
According to the present invention, the monoesters of polyglycerol fatty 
acids should be used. Note, diesters and the like have a poor foamability 
and taste and, therefore, cannot attain the objects of the present 
invention. The terms "monoesters" used in the present invention mean those 
having an average degree of esterification of 1.4 or less, especially 1.3 
or less. 
Typical examples of the polyglycerol fatty acid monoesters are hexaglycerol 
monomyristate, decaglycerol monomyristate, hexaglycerol monolaurate, and 
decaglycerol monolaurate, hexaglycerol monostearate, and decaglycerol 
monooleate. These polyglycerol fatty acid monoesters may be used alone or 
in any mixture thereof. 
The amount of the polyglycerol fatty acid monoesters to be formulated into 
the present oral composition is 0.5% to 5% by weight, preferably 0.5% to 
3% by weight. 
According to the present invention, the polyglycerol fatty acid monomers 
can be used alone as a surfactant in the oral composition, but other 
surfactants may be optionally used in addition to the polyglycerol fatty 
acid monoester. Examples of such other surfactants are anionic surfactants 
such as alkyl sulfates, olefin sulfonates, N-acylamino acids and their 
salts, monoglyceride sulfates, and soaps; nonionic surfactants such as 
fatty acid monoglycerides, fatty acid alkylolamides, polyoxyethylene 
sorbitan fatty acid esters, and sucrose fatty acid esters; and ampholytic 
surfactants. These surfactants may be used alone or in any mixture 
thereof. 
Of these other surfactants, it is especially preferably that N-acylamino 
acids or their salts be used in combination with the above-mentioned 
polyglycerol fatty acid monoesters. Thus, when the N-acylamino acids or 
their salts are used in combination with the polyglycerol fatty acid 
monoesters, the foamability of a polyglycerol fatty acids can be further 
increased and oral compositions having an excellent foamability and a 
better overall sensation in the mouth can be provided. 
The N-acylamino acids optionally usable in the present invention are those 
having a long-chain acyl group, especially saturated or unsaturated acyl 
groups having 8 to 20 carbon atoms. Typical examples of the acyl groups of 
such N-acylamino acids are the lauroyl group, myristoyl group, stearyl 
group, coconut fatty acid residues, hydrogenated tallow fatty acid 
residues, or residues of the mixed fatty acids mentioned above. 
On the other hand, although there are no limitations to the types of the 
amino acids used, the use of glutamic acid, sarcosine or 
N-methyl-.beta.-alanine or any mixture thereof is preferable. Typical 
examples of such N-acylamino acids are N-myristoyl glutamate, N-lauroyl 
glutamate, N-myristoyl sarcosinate, N-lauroyl sarcosinate, and 
N-lauroylmethyl-N-.beta.-aranate. Furthermore, the preferable salts are 
sodium salts and potassium salts. When the dicarboxylic acids and the like 
are used as the N-acylamino acid, any monometal salts or any dimetal salts 
may be used as the salt as long as the salt is water-soluble. 
Although there are no critical limitations to the amount of the N-acylamino 
acids or their salts in the present oral compositions, the preferable 
amount is 0.1% to 2% by weight based on the total amount of the oral 
composition. The amount ratio of the N-acylamino acids or their salts to 
the polyglycerol fatty acid monoesters is preferably 1 to 2 parts by 
weight of the N-acylamino acids or the salts thereof based upon 1 to 50 
parts of the polyglycerol fatty acid monoesters. 
The oral compositions according to the present invention may optionally 
contain any conventional ingredients, depending upon the types of the oral 
compositions. For example, dentifrices may optionally contain abrasives 
such as dicalcium phosphate, calcium carbonate, calcium pyrophosphate, 
insoluble sodium methaphosphate, and silicic anhydride; thickening agents 
such as glycerol, sorbitol, propylene glycol, and poyethylene glycol; 
binders such as carboxymethyl cellulose, carrageenan, sodium alginate, 
bees gum, hydroxyethyl cellulose, and polyvinyl alcohol; sweeteners such 
as sodium saccharin, glycyrrhizin salts, stebiocide, neohesperidyl 
dihydrochalcon, p-methoxycinnamic aldehyde, and perillartine; and flavors 
such as methanol, carvone, and anethole. Furthermore, bactericides such as 
fluorides (e.g., sodium monofluorophosphate, tin fluoride, and sodium 
fluoride) and chlorohexidine salts; phosphate compounds such as sodium 
phosphate; enzymes such as dextranase and amylase; anti-inflammatories 
such as E-aminocaproic acid, tranexamic acid, and allantoinate; and other 
effective components also may be optionally formulated. Also, in the case 
of oral clearers such as a mouth wash, various conventional ingredients 
may be appropriately formulated depending upon the properties of each 
product. According to the present invention, since the polyglycerol fatty 
acid monoesters substantially do not deactivate the effective components 
such as enzymes, these enzymes and other effective components may be 
formulated into the present oral composition without difficulty. 
As explained above, according to the present invention, the desired oral 
compositions having a high safety factor, little irritation of the mucos 
membrane, an excellent foamability, an excellent overall sensation in the 
mouth (e.g., taste and odor), and good juice effects can be provided by 
formulating the specified polyglycerol fatty acid monoesters. Furthermore, 
since the present oral compositions also have an excellent storage 
stability, are not easily discolored even when stored for a long time, and 
may stably contain bactericides, enzymes, and ionic effective components 
such as fluorine compounds, their functions can be properly effected 
during application use.

EXAMPLES 
The present invention will now be further illustrated by, but is by no 
means limited to, the following Experiments and Examples, wherein all 
percentages are expressed on a weight basis unless otherwise noted. 
Experiment 1 
The dentifrice compositions having the following formulation were prepared 
by using the foaming agents (i.e., surfactants) listed in Table 1. The 
overall sensation in the mouth and the stability of the dentifrice 
compositions were evaluated according to the below-mentioned standards. 
The results are shown in Table 1. 
______________________________________ 
% 
______________________________________ 
Dicalcium phosphate 45.0 
Silica 3.0 
Sodium carboxymethyl cellulose 
0.8 
Carrageenan 0.2 
Sorbitol liquid 26.0 
Propylene glycol 3.0 
Sodium saccharin 0.2 
Flavor 1.0 
Foaming agent 2.0 
Preservative 0.1 
Purified water Balance 
Total 100.0 
______________________________________ 
Evaluation Standards for Foaming 
o: Moderate foaming 
.DELTA.: Slight foaming 
x: Substantially no foaming 
Evaluation Standards for Taste 
o: Good 
.DELTA.: Slightly bitter taste 
x: Strong taste, cannot be used 
Evaluation Standards for Stability (50.degree. C., one month storage) 
o: No discoloration 
.DELTA.: Slight discoloration 
x: Strong discoloration 
TABLE 1 
__________________________________________________________________________ 
Overall Sensa- 
tion in Mouth 
Stability 
Foaming Agent 
Foaming 
Taste 
Discoloration 
__________________________________________________________________________ 
Present Invention 
No. 1 
Decaglycerol 
o o o 
monolaurate 
No. 2 
Hexaglycerol 
o or .DELTA. 
o o 
monomyristate 
Comparative 
No. 3 
Decaglycerol 
x x .DELTA. 
dioleate 
No. 4 
Tetraglycerol 
x o o 
monostearate 
No. 5 
Sucrose o .DELTA. or x 
.DELTA. or x 
monolaurate 
__________________________________________________________________________ 
Next, the dentifrice composition No. 1 (Foaming agent: decaglycerol 
monolaurate, present dentifrice) shown in Table 1 and the dentifrice 
composition No. 5 (Foaming agent: sucrose monolaurate, comparative 
dentifrice) shown in Table 1 were organoleptically evaluated with respect 
to the overall sensation in the mouth by a panel of 10 people. 
The results are shown in Table 2. 
TABLE 2 
______________________________________ 
Number of Panel Members 
Overall No. 1 is No.1 and No. 5 is 
Sensation better than No. 5 are better than 
in Mouth No. 5 the same No. 1 
______________________________________ 
Foamability 
3 5 2 
Taste 6 4 0 
______________________________________ 
As is clear from the results shown in Table 2, the dentifrice compositions 
according to the present invention containing polyglycerol fatty acid 
monoesters having a glycerol polymerization degree of 6 or more have an 
appropriate foamability and good taste, exhibit no substantial 
discoloration, give an excellent overall sensation in the mouth and are 
stabile. Furthermore, even when the denifrice composition according to the 
present invention is compared to that containing sucrose monolaurate, the 
taste of the present dentifrice is better than the dentifrice containing 
sucrose monolaurate, although there are no substantial differences in 
these dentifrice compositions. 
Experiment 2 
The dentifrice compositions having the same formulation as used in 
Experiment 1 were prepared, except that the foaming agents shown in Table 
3 were used. The taste and stability (discoloration) of the dentifrice 
compositions were evaluated under the same evaluation standards as used in 
Experiment 1, and the foaming and the juice effect were evaluated 
according to the following evaluation standards. 
The results are shown in Table 3. 
Evaluation Standards for Foaming 
.circleincircle. : Good foaming 
o: Appropriate foaming 
.DELTA.: Slight foaming 
x: No substantial foaming 
Evaluation Standards for Juice Effect 
o: Good (Juice taste is unchanged) 
x: Poor (Juice taste changed) 
TABLE 3 
__________________________________________________________________________ 
Foaming Agent Overall Sensation in Mouth 
Stability 
(Formulation amount) 
Foaming 
Taste 
Juice effect 
Discoloration 
__________________________________________________________________________ 
Present 
No.1 
Decaglycerol monolaurate (2.0%) 
o o o o 
Invention 
No. 6 
Decaglycerol monolaurate (1.5%) 
.circleincircle. 
o o o 
+ 
N--lauroyl sarcosinate (0.5%) 
No. 7 
Decaglycerol monolaurate (1.5%) 
.circleincircle. 
o o o 
+ 
N--hydrogenated tallow coconut 
oil mixed fatty acid glutamate 
(0.5%) 
No. 8 
Decaglycerol monolaurate (1.5%) 
.circleincircle. 
o o o 
+ 
N--lauroyl methyl-.beta.-alanate 
(0.5%) 
__________________________________________________________________________ 
Next, the dentifrice composition No. 1 (Foaming agent: Decaglycerol 
monolaurate) shown in Table 3 and the dentifrice composition No. 6 
(Foaming agent: Decaglycerol monolaurate +N-lauroyl sarcosinate) shown in 
Table 3 were organoleptically evaluated with respect to the overall 
sensation in the mouth by a panel of 10 people. 
The results are shown in Table 4. 
TABLE 4 
______________________________________ 
Number of Panel Members 
Overall No. 1 is Nos. 1 No. 6 is 
Sensation 
better than and 6 are 
better than 
in Mouth No. 6 the same No. 1 
______________________________________ 
Foaming 0 2 8 
Taste 2 6 2 
______________________________________ 
As is clear from the results shown in Tables 3 and 4, the dentifrice 
composition Nos. 6, 7, and 8 containing, as the foaming agent, both the 
polyglycerol fatty acid monoester and the N-acylamino acids, exhibited a 
remarkably excellent foamability, when compared to the dentifrice 
composition No. 1 containing, as the foaming agent, only the polyglycerol 
fatty acid monoester, although there are no substantial differences in the 
taste and the discoloration thereof. Furthermore, the polyglycerol fatty 
acid monoesters do not substantially change the juice taste and exhibit a 
good juice effect. Furthermore, it has also been found that, even when the 
N-acylamino acids are used in combination with the polyglycerol fatty acid 
monoesters, the juice effect is not inhibited. 
Experiment 3 
______________________________________ 
Formulation % 
______________________________________ 
Aluminum hydroxide 40.0 
Silica 2.0 
Propylene glycol 2.0 
Sorbitol liquid 15.0 
Glycerol 15.0 
Sodium alginate 1.0 
Sodium saccharin 0.2 
Dextranase 5000 u/g 
Geratin 0.2 
Sodium monofluorophosphate 
0.76 
Decaglycerol monomyristate 
2.5 
Flavor 1.0 
Preservative q.s. 
Purified water Balance 
Total 100.0 
______________________________________ 
The tooth paste prepared in the above-mentioned formulation was stored at a 
temperature of 40.degree. C. for one month and the remaining activity of 
dextranase was evaluated thereafter. 
It was found that the remaining activity of dextranase was 70% or more of 
the activity when prepared. Thus, it was confirmed that the formulation of 
the polyglycerol fatty and monoesters into the oral compositions does not 
inhibit but stably retains the activity of the enzyme dextranase. 
______________________________________ 
Example 1: Tooth paste 
Formulation % 
______________________________________ 
Aluminosilicate 20.0 
Glycerol 15.0 
Sorbitol liquid 40.0 
Polyethylene glycol #400 
4.0 
Sodium carboxymethylcellulose 
1.2 
Sodium saccharin 0.2 
Hexaglycerol monostearate 
2.0 
N--lauroyl glutamate 0.5 
Flavor 1.0 
Coloring agent q.s. 
Chlorohexidine gluconate 
0.01 
Purified water Balance 
Total 100.0 
______________________________________ 
Example 2: Tooth paste 
Formulation % 
______________________________________ 
Calcium carbonate (heavy) 
30.0 
Calcium carbonate (light) 
15.0 
Propylene glycol 3.0 
Sorbitol liquid 30.0 
Sodium carboxymethylcellulose 
1.0 
Sodium saccharin 0.1 
Tranexamic acid 0.1 
Decaglycerol monolaurate 
1.0 
N--lauroyl-N--methyl-.beta.-aranate 
1.0 
Flavor 1.0 
Preservative q.s. 
Purified water Balance 
Total 100.0 
______________________________________ 
Example 3: Tooth paste 
Formulation % 
______________________________________ 
Dicalcium phosphate 50.0 
Silica 3.0 
Propylene glycol 2.0 
Sorbitol liquid 25.0 
Sodium carboxymethylcellulose 
0.8 
Carrageenan 0.3 
Sodium saccharin 0.2 
Hexaglycerol monomyristate 
2.0 
Sucrose monomyristate 1.0 
Allantoin chlorohydroxy aluminum 
0.1 
Flavor 1.0 
Preservative q.s. 
Purified water Balance 
Total 100.0 
______________________________________ 
Example 4: Tooth paste 
Formulation % 
______________________________________ 
Zirconosilicate 15.0 
Silica 2.0 
Polyethylene glycol #400 
3.0 
Sorbitol liquid 60.0 
Sodium carboxymethylcellulose 
1.4 
Sodium saccharin 0.2 
Decaglycerol monolaurate 
1.5 
N--myristoyl glutamate 
1.0 
.beta.-Glycyrrhezinic acid 
0.01 
Tocopherol acetate 0.1 
Sodium fluoride 0.2 
Flavor 1.0 
Coloring agent q.s. 
Purified water Balance 
Total 100.0 
______________________________________ 
Example 5: Tooth paste 
Formulation % 
______________________________________ 
Aluminum hydroxide 35.0 
Aluminum oxide 2.0 
Propylene glycol 3.0 
Sorbitol liquid 15.0 
Glycerol 5.0 
Sodium carboxymethylcellulose 
1.2 
Sodium saccharin 0.1 
Sodium chloride 10.0 
Decaglycerol monooleate 
1.5 
N--myristoyl sarcosinate 
0.5 
Isopropylmethyl phenol 
0.05 
Flavor 1.0 
Purified water Balance 
Total 100.0 
______________________________________ 
Example 6: Wet dentifrice 
Formulation % 
______________________________________ 
Dicalcium phosphate 35.0 
Calcium carbonate 40.0 
Glycerol 10.0 
Sodium carboxymethylcellulose 
0.3 
Sodium saccharin 0.2 
Decaglycerol monolaurate 
1.5 
Flavor 1.5 
Purified water Balance 
Total 100.0 
______________________________________ 
Example 7: Mouth wash 
Formulation % 
______________________________________ 
Ethanol 10.0 
Glycerol 10.0 
Sorbitol liquid 5.0 
Citric acid 0.1 
Sodium citrate 0.4 
Sodium saccharin 0.05 
Hexaglycerol monolaurate 
1.5 
Flavor 1.0 
Purified water Balance 
Total 100.0 
______________________________________ 
The oral compositions prepared in Examples 1 to 7 all gave a good overall 
sensation in the mouth and were stable.