JP2002012539A - Water-based liquid agent for external use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-based liquid agent for external use presenting a keratolytic action and a moisture-retaining action owing to urea and good in sense of use. SOLUTION: This water-based liquid agent is prepared by blending urea, a polyhydric alcohol, a water-soluble calcium salt and a bamboo extract solution in water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous solution for external use used as cosmetics, quasi-drugs, pharmaceuticals, etc., and more particularly to an aqueous solution for external use comprising urea in water.

[0002]

2. Description of the Related Art In general, urea is known to have a keratolytic action to remove old keratin of the skin, a moisturizing action to increase the water holding power of keratin, and to have a slight antibacterial property. It is widely used as an active ingredient contained in an aqueous external preparation for skin diseases such as xeroderma and atopic skin.

In recent years, due to its keratolytic and moisturizing effects, it has been widely used as an active ingredient in aqueous external preparations such as lotions and quasi-drugs.

[0004] Polyhydric alcohols such as glycerin and propylene glycol have the property of promoting the moisturizing action of urea, and thus are blended together with urea as an active ingredient in the above-mentioned aqueous external solution.

[0005]

However, as described above, an aqueous topical solution in which urea and a polyhydric alcohol are blended in water, due to the moisturizing action of urea, becomes sticky for a long time after being applied to the skin. The feeling remained, and the feeling of use was unfavorable.

Moreover, urea is hydrolyzed when it coexists with water for a long period of time to generate ammonia, and the pH of aqueous solution for external use is reduced.
However, applying such an aqueous topical solution whose pH value has increased due to the hydrolysis of urea to the skin may impair the ability of the skin to neutralize alkali and promote bacterial contamination of the skin. Problems may occur. That is,
Aqueous external preparations containing urea cannot be used over a long period of time due to a rise in pH, and are not effective for long-term storage, ie, have poor so-called stability over time.

The present invention has been made in view of the above-mentioned conventional problems, and a first object of the present invention is to provide an aqueous topical solution which exhibits a keratolytic action and a moisturizing action by urea and has a good feeling in use. Further, it is a second object of the present invention to provide an aqueous external preparation having good stability over time.

[0008]

Means for Solving the Problems The present inventor has conducted intensive studies to solve the first problem, and as a result, the so-called calcium-containing active solution in which calcium has been ionized and dissolved in water has a hydrogen content of water molecules. Attention was paid to the fact that the bond was broken and the viscosity became much lower than that of ordinary water, and the bamboo extract was found to stabilize calcium ions dissolved in water in the ionic state, completing the present invention. I came to.

That is, the present invention relates to an aqueous external preparation characterized by comprising urea, a polyhydric alcohol, a water-soluble calcium salt, and a bamboo extract in water.

In the present invention, although its action is not clear, the water-soluble calcium salt dissolves in water to form calcium ions, which are stabilized in an ionic state by the bamboo extract and reduce water clusters. By doing so, it is considered that the stickiness of the liquid preparation is suppressed and the feeling of use is improved. The effect of the bamboo extract on stabilizing calcium ions is based on the characteristic that the bamboo extract exhibits an extremely low oxidation-reduction potential despite the fact that the bamboo extract usually exhibits an acidity (generally, a pH of about 3.0). It is considered that calcium ions are stabilized by the reducing property.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the blending amount of urea is preferably 1 g to 5 g per 100 ml of an aqueous topical solution. Glycerin,
Examples thereof include propylene glycol and polyethylene glycol. In particular, from the point of view designation component,
Glycerin is preferred. The amount of the polyhydric alcohol to be added is 0.1 ml to 100 ml of the aqueous topical solution.
0.9 ml is preferred.

As the water-soluble calcium salt, calcium chloride is preferable, and dihydrate calcium chloride is particularly preferable. As the compounding amount of calcium chloride, an equivalent amount of an anhydride is 10 to 50 m with respect to 100 ml of an aqueous topical solution.
g is preferred.

In the present invention, the bamboo extract is
An extract extracted from bamboo, for example, it can be obtained by squeezing bamboo, or by crushing bamboo and heating and extracting it with a solvent such as water or alcohol. The compounding amount of this bamboo extract is equivalent to a squeezed liquid obtained by squeezing bamboo, and is 0.1 ml with respect to 100 ml of the aqueous external preparation.
It is preferably from 0.01 to 0.09 ml, and in a solid content equivalent amount (an amount corresponding to a state in which a liquid content is completely evaporated),
0.2 to 4.5 mg per 100 ml of aqueous topical solution
Is preferred. The solid content equivalent is a value obtained by evaporating the bamboo extract almost completely on a water bath, drying it at 100 ° C. for 3 hours, and measuring its weight. In addition, as the bamboo, Moso bamboo, true bamboo, tan bamboo and the like can be used.

Further, in the present invention, a composition containing an organic acid and an organic acid ammonium is preferred. Since organic acids and ammonium ammonium salts act as buffer solutions and suppress the decomposition of urea by the common ionic effect, if organic acids and ammonium salts of organic acids are added, the rise in pH due to the generation of ammonia is suppressed. It has excellent stability over time, that is, solves the second problem. In addition, the bamboo extract may cause the generation of ori as the pH value increases (the reason is not clear), but the increase in the pH value is suppressed by the combination of the organic acid and the organic acid ammonium. Therefore, generation of the deposit can be suppressed, and a sharp decrease in the commercial value can be prevented.

Examples of the organic acid include lactic acid, citric acid, tartaric acid and the like.
It is preferably 0.01 to 0.09 ml with respect to 1.

Examples of the organic acid ammonium include ammonium tartrate and diammonium hydrogen citrate.
Among them, diammonium hydrogen citrate is preferred. When diammonium hydrogen citrate is used, the mixing amount is 0.1 to 0.9 with respect to 100 ml of the aqueous external preparation.
g is preferred.

In particular, a combination of lactic acid as the organic acid and ammonium dihydrogen citrate as the organic acid ammonium is preferable.
With respect to 00 ml, lactic acid 0.03-0.07 ml and ammonium dihydrogen citrate 0.4-0.6 g, that is, lactic acid 0.03-0.07% (V / V), ammonium dihydrogen citrate 0 0.4 to 0.6% (W / V) is preferred. If the amount is within the above range, the pH value is set to 4.5 or more and 7.
It can be kept at 0 or less, and can be used for a longer period. Also, by increasing the pH to 8.0 or more,
Due to some change in the components of the bamboo extract, odor is generated in the aqueous external preparation, but by using the above amount, the pH value is maintained at 7.0 or less for a long time (228 days or more). This can suppress the generation of ori in the aqueous external use liquid agent, and can suppress a decrease in commercial value due to the generation of ori.

In the present invention, it is preferable that at least any one of psyllium extract and hinokitiol is further blended. Oat extract and hinokitiol are components originally having antibacterial properties, and since they exhibit an antiseptic effect, by being blended with these components,
The aqueous topical solution becomes hard to rot for a long time. The amount of these components is as follows.
0.1 to 0.8 ml is preferable for 00 ml, and in the case of hinokitiol, 1 to 100 ml of an aqueous topical solution is used.
Preferred is 1 to 19 mg.

In the present invention, a composition further containing trehalose is preferable. Since trehalose is excellent in moisturizing properties, by adding such trehalose, without increasing the amount of urea,
The moisturizing property of the aqueous topical solution can be further enhanced. The blending amount of trehalose is preferably 0.5 to 1.5 g per 100 ml of the aqueous solution for external use.

Further, in the present invention, the pH is 4.5 to 4.5.
Those having a range of 7.0 are preferred. Within such a range, the calcium ions are sufficiently maintained in an ionic state, and there is little possibility that the aqueous external preparation is turbid due to the generation of the deposit, and the possibility that the commercial value is reduced due to the turbidity is also reduced.

[0021]

Example 1 3 g of urea, 0.5 ml of glycerin, 0.4 ml of oak extract (trade name "Ooba liquid E", manufactured by Ichimaru Falcos Co., Ltd.), hinokitiol (trade name "hinokitiol", manufactured by Takasago International Corporation) 15 mg, trehalose 1 g, diammonium hydrogen citrate 0.5 g, lactic acid 0.1 g.
05 ml, NIC solution (manufactured by Le Mic Research Inc.)
Purified water was added to 1 ml to prepare a 100 ml solution, which was used as the aqueous external preparation of Example 1. Here, the NIC solution is a solution prepared by adding ion-exchanged water to 5 g of calcium dichloride and 5 ml of bamboo extract to make 100 ml. The bamboo extract is made of 500 g of bamboo powder from Yasaka, Kyoto, and 4000 m of water.
After heating to 380 ° C (pressure about 2 MPa),
After cooling, 2000 ml of the supernatant was extracted.
In addition, when the amount of solid content was measured by evaporating water, 5 ml of bamboo extract contained 175 mg of solid content.

[0022] except that the Example 2 Citric acid ammonium dihydrogen was 1g, thus preparing a water-based liquid for external use of Example 2 in the same manner as in Example 1.

Example 3 Except that the amount of ammonium dihydrogen citrate was changed to 0.2 g,
An aqueous topical solution of Example 3 was prepared in the same manner as in Example 1.

Example 4 Except that the amount of ammonium dihydrogen citrate was 0.1 g,
An aqueous external preparation of Example 4 was prepared in the same manner as in Example 1.

[0025] except for using Example 5 Citric acid ammonium dihydrogen-free formulations were prepared aqueous liquids for external use of the Example 5 in the same manner as in Example 1.

Test Examples Each of the aqueous solutions for external use prepared in each Example was maintained at 40 ° C., and the pH was measured immediately after preparation, 6, 10, 14, 14, 17, 24, 31, and 38 days after preparation. Table 1 shows the measurement results.

[0027]

[Table 1]

As is evident from Table 1, the pH value immediately after the preparation can be shifted from the strong acidic range to the neutral range by the addition of the diammonium hydrogen citrate salt. It can be seen that the rise can be suppressed. In particular, when lactic acid 0.05% (V / V) and diammonium hydrogen citrate 0.5% (W / V) are blended, it is suitable for human skin even after 38 days from immediately after preparation. PH range that can be used (generally, 4.5 to 7.0 (especially, 4.0 to 7.0).
5 to 6.5) is preferred. ), And according to the results of the Ministry of Health and Welfare accelerated testing,
It can be seen that it can be used in a pH range suitable for human skin for 228 days immediately after preparation.

[0029]

As described above, the aqueous topical solution of the present invention exhibits a keratolytic action and a moisturizing action by the compounded urea and polyhydric alcohol, and has a water-soluble calcium salt,
The bamboo extract has the effect of reducing stickiness and improving the usability.

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Claims (5)

[Claims] 1. An aqueous external liquid preparation comprising urea, a polyhydric alcohol, a water-soluble calcium salt, and a bamboo extract in water. 2. The aqueous topical solution according to claim 1, further comprising an organic acid and an organic ammonium salt. 3. The aqueous liquid preparation for external use according to claim 1, wherein at least one of psyllium extract and hinokitiol is blended. 4. The method according to claim 1, wherein trehalose is blended.
4. The aqueous topical solution according to any one of items 1 to 3, wherein 5. The aqueous solution for external use according to claim 1, wherein the pH is 4.5 to 7.0.