JPS5920217A - Aqueous jellylike composition stably containing urea - Google Patents

Abstract

PURPOSE:The titled stable composition, prepared by adding an ammonium compound and a carboxyvinyl polymer together to an aqueous composition of urea, and adjusting the pH to a specific range, capable of inhibiting the decomposition of urea by the synergistic effect thereof, and useful for a medicinal or cosmetic base. CONSTITUTION:An aqueous jellylike composition prepared by adding 0.5-5wt% ammonium compound, e.g. ammonium chloride or ammonium sulfate, and 0.5- 5wt% carboxyvinyl polymer having preferably within 1,000,000-3,000,000 molecular weight range as an inhibitor for the decomposition of the urea to an aqueous composition containing 1-48wt% urea, and adjusting the pH to 5.5-7.5 with a basic compound, e.g. an alkali metallic hydroxide or alkanolamine, and containing stably incorporated urea. In case the amount of the uea is 1-10wt%, the composition is used as a base for cosmetics having humectant action. If the amount of the urea exceeds 10wt%, the composition is used as a base in medicines having action on the integument utilizing the softening action on keratin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aqueous jelly-like composition stably containing urea, which is useful as a medicinal or cosmetic base.

Urea exists in living organisms, and as a result of changing protein polypeptides, it increases its solubility, and has antibacterial effects, proteolytic denaturation effects, and advanced water-retaining effects.
It also has unique properties such as advanced skin absorption and other important pharmacological effects in dermatology. Furthermore, it is also known that a highly concentrated urea aqueous solution exhibits a mild keratin softening effect. Urea preparations that take advantage of these characteristic effects have recently been used as skin moisturizers and therapeutic agents for highly keratinized skin. In these urea-containing preparations, when the urea concentration is approximately 10 wt% or more, it is generally used as a skin moisturizer.
If it is still more than about 10 wt%, the skin is highly keratinized,
For example, it is usually used as a therapeutic agent for keratosis such as ichthyosoma vulgaris1, and in this case it is formulated as a qZW type emulsion. In addition, skin 1+'i fungal treatment 4f, which applied the keratin softening effect of urea, was also published in JP-A-52-1.
It is disclosed in Publication No. 0424.

However, urea decomposes very easily and generates ammonia, which increases the pH of the base material. for the decomposition of urea)
The increase in Pfl caused by 1Q impairs the skin's alkali neutralizing ability, promotes bacterial infection of the skin, and furthermore significantly reduces the commercial value due to the generation of ammonia odor. Therefore, urea has had the problem of being difficult to formulate into formulations.

In particular, this tendency increases as the concentration of urea increases.

Conventionally, as a method of suppressing the decomposition of urea, a method of adding neutral amino acids (Aus) IJ African Patent No. 23762
No. 5), method of adding lactic acid (West German openness [No. 19
11144), a method of adding ammonium compounds such as ammonium chloride (Japanese Patent Publication No. 46-1i010),
Method of adding aliphatic dicarboxylic acid (JP-A-52-10
No. 5225), method of adding allantoin (Japanese Patent Application Laid-open No. 5
A number of methods have been disclosed, including a method in which hydroxylamine mineral salt is completely added (Japanese Patent Application Laid-open No. 122753/1983). However, none of these methods can be said to be sufficiently effective, and it has been difficult to apply urea to cosmetics or external medicines and ultimately commercialize them.

The present inventors conducted research focusing on formulating urea in the form of an aqueous jelly in order to stably incorporate urea into cosmetics and external drugs. When formulating urea, heating it to high temperatures accelerates the decomposition of urea, and a large amount of surfactant must be used as an emulsifier to avoid adverse effects on the skin caused by surfactants. It's because there isn't.

The present inventors conducted intensive studies with the aim of stably formulating urea into an aqueous jelly-like formulation, and found that the combination of a specific urea decomposition inhibitor and a water-soluble polymer synergistically inhibits the decomposition of urea. They have found that this can be suppressed and have completed the present invention.

That is, the present invention relates to an aqueous jelly-like composition stably containing urea, which is characterized in that it contains an ammonium compound and a carboxyvinyl polyester, and has a pH of 1-5.5 to 7.5.

The amount of urea in the aqueous jelly composition of the present invention is 1
~48wt%. If the amount of urea is less than 1wt%, the moisturizing effect on the skin will be poor, and if it exceeds 48tvt%, urea crystals will precipitate at low temperatures as the urea saturation concentration approaches, which is not preferable. When the amount of urea is about 1 to 10 wt%, the keratin softening effect is weak, so it can be applied as an aqueous jelly base for cosmetics with a moisturizing effect. When the blending amount of urea exceeds 10 wt%, it can be used as a base for a skin-acting agent by utilizing its softening effect on keratinized skin.

The ammonium compounds used in the present invention are ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium phosphate, ammonium acetate, ammonium lactate and ammonium oxalate. The amount of ammonium compound added is 0.5 to 5 parts. If the amount of ammonium compound added is less than 0.5 wt%, the effect as a urea decomposition inhibitor will be extremely weak, and if it is added in more than 5 parts, the cold resistance of the aqueous jelly composition will decrease, which is not preferable. .

The carboxyvinyl polymer used in the composition of the present invention preferably has a molecular weight of about 1,000,000 to 3,000,000, and its blending amount is 0.5 to 5 wt.
% is appropriate. If the amount of carboxyvinyl polymer blended is 0.5 wt To, it is difficult to maintain a jelly-like state, and especially when stored at a high temperature, the product becomes a liquid with high fluidity, which is not preferable. On the other hand, if the blending amount exceeds Swt, the jelly state becomes too hard, which is not preferable.

In the composition of the present invention, examples of the pH adjusting agent for adjusting the pH to 5.5 to 7.5 include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, monoethanolamine, diethanolamine, and triethanolamine. Examples include alkanolamines such as amines, basic amino acids such as lysine, arginine, ornithine, and basic compounds such as ammonia. If the pH is less than 5.5, the carboxyvinyl polymer will not have a thickening effect and will not become jelly-like. When the pH exceeds 7.5, the decomposition of urea is promoted and freezing is not good.

The composition of the present invention is characterized by suppressing the decomposition of urea by using the above-mentioned ammonium compound and carboxyvinyl polymer in combination and adjusting the pH to 5.5 to 7.5. is achieved through the synergistic effect of the combination of each component. Therefore, by blending only carboxyvinyl polymer, P l (5.5 to 7.5
or by using other water-soluble polymers and ammonium compounds in place of carboxyvinyl polymers.
If the cypress composition of the present invention lacks any of the essential points, such as when adjusted to I('fr: 5.5 to 75), the stability of urea is inferior to the composition of the present invention.The composition of the present invention Although each component of the product is known, the stabilization of urea due to their synergistic effect could not be predicted from the prior art.

Although the reason why urea stably exists in the composition of the present invention is not clear, it is thought that the raw electricity is stabilized by the interaction between the carboxyl group in the carboxyvinyl polymer and the ammonium compound.

An example of the method for producing the composition of the present invention is to heat and dissolve the carboxyvinyl polymer, PH adjuster, and water at about 80°C, mix thoroughly, and then cool to 50 to 60°C.
When urea and ammonium compound are added and mixed, an aqueous jelly-like composition is obtained.

The aqueous jelly composition of the present invention has a urea concentration of 10 wt%.
Those exceeding 20% can be used as therapeutic agents for keratosis such as ichthyosis vulgaris and atopic skin, but they are most suitable as bases for cosmetics or external medicines. Specifically, the aqueous jelly-like composition of the present invention is used as a base, and commonly used cosmetic additives and drugs such as humectants, ultraviolet absorbers, fragrances, colorants, and preservatives are added to moisten the urea. It can be made into jelly-like cosmetics or external medicines that take advantage of its keratin softening and keratin softening effects. In particular, in order to apply the composition of the present invention to all external medicines, antifungal agents such as benzalkonium chloride, clotrimazole, virolnidoline, tolnaftate, and untesylenic acid, antihistamines such as Schiff-nhydramine hydrochloride,
By adding drugs such as anti-inflammatory agents, it is possible to obtain therapeutic agents for skin diseases such as skin albinism (athlete's foot) treatment, hyperkeratosis treatment, and itching treatment.

When blending water-insoluble cosmetic additives and drugs, they may be dissolved or dispersed in an appropriate solvent using a surfactant as necessary. .

Furthermore, other ingredients may be added to the composition of the present invention, such as a viscosity modifier to adjust the jelly hardness and a PH buffer to further stabilize the PH.

Further, the present invention will be explained in detail with reference to Examples.

Example 1.2, Comparative Examples 1 to 4 The formulations of group A shown in Table 1 were heated and mixed at about 80°C, then cooled to 50 to 60°C, and the formulations of group B were added to form an aqueous jelly. A composition was obtained. However, the composition of Comparative Example 1 without the addition of a neutralizing agent had a low viscosity and did not form a jelly-like composition.The aqueous jelly-like composition thus obtained was stored at 40°C and...
PH was measured after i days, 10 days, 15 days, and 30 days to examine the stability of urea. The results are shown in Table 1.

As is clear from the results in Table 1, the urea in the composition of the present invention in which carboxyvinyl polymer and ammonium chloride are used in combination and the pH is adjusted is stable, whereas the comparative example lacking any of the constituent elements of the present invention is stable. Decomposition of urea progressed in all cases, and an ammonia odor was generated.

1 margin, 1st table note l) Carpoball 941 (trade name, manufactured by Gutdrich, molecular weight 1.000. (100-1,500,000)
) Examples 3 to 7 Using the compositions shown in Table 2, the formulations shown in Table 2 were treated according to Example 1 to obtain aqueous jelly compositions. Heat this to 40℃ for 3
After storage for 0 days, the pH was measured to examine the stability of urea. The results are shown in Table 2.

Table 2 From the results shown in Table 2, it is clear that the composition of the present invention is stable in the range of urea concentration from low to high.

Examples 7 to 10 Aqueous jelly compositions were prepared in the same manner as in Example 1, except that ammonium chloride in the aqueous jelly composition of Example 1 was replaced with other ammonium compounds shown in Table 2. After storing this product at 40°C for 30 days, Pll and dllll were determined and the stability of urea was examined. The results are shown in Table 3.

Table 3 It is clear from the results in Table 3 that the aqueous jelly composition of the present invention does not lose urea even when stored at 40°C for 30 days, and the viscosity of the jelly does not change. I didn't.

Reference Example 1 Hand jelly manufactured by Ill Group A having the composition shown in Table 4 was heated and mixed at about 80° C., and the carboxyvinyl polymer was uniformly dissolved and prepared, and then cooled. The thus obtained No.Ndo jelly was easy to use and had a high emollient effect.

Table 4 Reference Example 2 Preparation of a therapeutic agent for keratosis Group A having the composition shown in Table 5 was heated and mixed at about 80°C to uniformly dissolve the carboxyvinyl polymer, and then heated to about 60°C.
The temperature was lowered and urea was added, and finally PI was adjusted with lysine and cooled. The aqueous jelly-like composition thus obtained was effective as a therapeutic agent for keratosis such as ichthyosis vulgaris.

Table 5 Note 2) Carboball 940 (trade name, Dudli, manufactured by Chi Co., Ltd., molecular weight 2.000,00 Q - 3,000,000
) was used.

Reference Example 3 Preparation of therapeutic agent for skin mycosis Group A having the composition shown in Table 6 was heated and mixed at about 80°C to uniformly dissolve the carboxyvinyl polymer, and then the temperature was lowered to about 60°C and the mixture of Group B was prepared. was added, and Group 0, which had been heated and dissolved in advance, was added little by little. Finally, neutralizing agent D was added to adjust the pH and the mixture was cooled. The resulting aqueous jelly composition was found to be effective in treating skin mycosis.

In order to investigate the stability of urea contained in the aqueous jelly compositions of Reference Examples 1 to 3 in Table 6, the I'H of each aqueous jelly composition was measured immediately after preparation and after storage at 40°C for 30 days ( The measurement temperature was 25°C). The results are shown in Table 7.

The aqueous jelly compositions of Reference Examples 1 to 3 in Table 7 all have no ammonia odor and have low pH increases, so it is clear that the decomposition of urea is suppressed. .

Claims (1)

[Scope of Claims] 1. An aqueous composition containing 1 to 48 wt% of urea, which contains an ammonium compound and a carboxyvinyl polymer and has a pH of 5.5 to 7.5. Aqueous jelly composition. 2. Ammonium compound is 0.5-5 wt%,
and carboxyvinyl polymer from 0.5 to 5 wt.
The composition according to claim 1, which contains To. 3. The composition according to claim 1, wherein the ammonium compound is selected from ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium phosphate, ammonium acetate, ammonium lactate, and ammonium oxalate. 4 The molecular weight of carboxyvinyl polymer is 1.00
(1. (100-3.0 old), 000) The composition according to claim 1. 5. A base whose pH is selected from alkali metal hydroxides, alkanolamines, basic amino acids, and ammonia. A composition according to claim 1 prepared by: