JPH06100451A - Skin external agent - Google Patents

Abstract

PURPOSE:To provide a non-irritative skin external agent containing urea and glycyrrhetic acid as active ingredients, good in stability, excellent in using touch, and useful for the therapy of skin hyperkeratosis and drying skin pruritus. CONSTITUTION:The skin external agent contains glycyrrhetic acid and urea in amounts of 0.1-0.5wt.% and 8-25wt.%, respectively, as active ingredients in the whole composition. 40-80wt.% of water and an oily base material component, an antiseptic agent, a neutralizing agent, a chelating agent, etc., are further added in suitable amounts, respectively, and prepared into the skin external agent by a conventional method. The skin external agent is preferably prepared into an emulsion, and 0.1-4wt.% of an emulsifier (e.g. sorbitan monostearate) is therein added for the emulsification of the raw materials. Finely ground glycyrrhetic acid having an average particle diameter of <=40mum is preferably used as the glycyrrhetic acid. The skin external agent has excellent moisture- retaining action, corneum-softening action, antipruritic action, and inflammatory action, and is useful for the therapy of infant xeroderma, senile xeroderma, shagreen skin, etc.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a skin external preparation, more specifically, urea and glycyrrhetinic acid as active ingredients,
The present invention relates to a skin external preparation useful for treating keratodermatitis and pruritus dermatitis dermatosum.

[0002]

BACKGROUND OF THE INVENTION Dry skin diseases are not only dry and keratinized skin, but also pruritus, as typified by atopic skin and senile dry dermatosis. Is a disease associated with. Particularly in the case of senile dry dermatosis, the amount of hormones in the skin of the elderly decreases with age, and the secretion of sebum decreases, which makes it easier to dry and keratinize, which causes eczema, itching, etc. , It may cause dermatitis all over the body, especially for bedridden old people, itching is said to cause secondary disorders such as insomnia, irritability, and loss of appetite. It can no longer be said to belong to some people.

Conventionally, the external preparations for skin used for dry skin diseases have an effect on either dry skin or pruritus, and no single preparation can treat both. Therefore, when a commercially available product is used for the treatment of dry skin disease, two drugs must be used in combination, which is extremely inconvenient for the patient.

For example, as an agent for treating dry skin disease, an external preparation containing urea as an active ingredient is used. However, although urea has an excellent moisturizing effect, it has almost no antipruritic effect, and therefore, even if these external preparations are used, a sufficient effect cannot be obtained for severe itching diseases. Therefore, an alcohol preparation in which urea, an antihistamine, and a local anesthetic are combined and these drugs are dissolved has been tried (Japanese Patent Laid-Open No. 3-29221), but alcohol is applied to dry and sensitive skin. There was a problem that it was not preferable.

On the other hand, as drugs having antipruritic effects, external preparations containing anti-inflammatory agents such as glycyrrhetinic acid, diphenhydramine, chlorpheniramine maleate, dexamethasone and antihistamines are used. Of these, plaster is known as a preparation containing glycyrrhetinic acid (Japanese Patent Publication No. 4-25927). However, glycyrrhetinic acid is hardly soluble in oils and fats, hydrocarbons, and water, and therefore it is difficult to formulate it.In the case of the plaster, a solvent for dissolving the glycyrrhetinic acid is indispensable, and it is safe for the skin and used. There was a problem in terms of feeling.

Therefore, there has been a demand for an external preparation for skin which is effective for treating both dry skin and pruritus by one agent.

[0007]

Under the circumstances, as a result of intensive studies by the present inventors, the emulsion external preparation containing urea and glycyrrhetinic acid as active ingredients has good stability,
The present invention has been completed by discovering that it has an excellent feeling in use, is non-irritating, and has an extremely excellent effect on the treatment of keratodermatitis and pruritus dermatitis.

That is, the present invention provides a skin external preparation containing urea and glycyrrhetinic acid as active ingredients.

Glycyrrhetinic acid used in the present invention is
It is a hydrolysis product of glycyrrhizin (glycyrrhizic acid), which is a licorice extract, has anti-inflammatory and antipruritic effects, and is widely used as a therapeutic agent for eczema, neurodermatitis, and pruritus dermatitis. It has a structural formula.

[0010]

[Chemical 1]

This glycyrrhetinic acid is insoluble in water, and although it is usually used, it has an average particle size of 120 to 2
It is 00 μm. In the present invention, it is preferable to finely pulverize glycyrrhetinic acid and use the one having an average particle diameter of 40 μm or less. Here, in order to micronize glycyrrhetinic acid, it may be carried out according to a usual method, and for example, it can be micronized using an atomizer or the like. By pulverizing in this way, the surface area of glycyrrhetinic acid can be increased, the dissolution rate can be increased, and the dispersion stability can be improved.

In the present invention, glycyrrhetinic acid is preferably added in an amount of 0.1 to 0.5% by weight (hereinafter referred to simply as%), particularly 0.3 to 0.5% in the total composition.

The external preparation for skin of the present invention contains urea as an active ingredient together with the glycyrrhetinic acid, and it is preferable to add 8 to 25%, particularly 10 to 20% of urea in the total composition.

The external preparation for skin of the present invention is preferably an emulsion, and examples of emulsifiers used in this case include polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitan monostearate, and polyoxyethylene sorbitan monooleate. , Sorbitan monostearate and the like. These emulsifiers are present in the total composition at 0.1 to
It is preferable to add 4.0%, particularly 0.2 to 3.0%.

Water is preferably added in an amount of 40 to 80%, particularly 45 to 75%, in the total composition.

Further, in addition to the above-mentioned components, the external preparation for skin of the present invention includes components used in usual external preparations such as petrolatum, liquid paraffin, squalane, polyethylene glycol, stearyl alcohol, cetanol, stearic acid, olive oil, myristin. An oily base component such as octyldodecyl acid, an antiseptic, a neutralizing agent, a chelating agent and the like can be appropriately added within a range that does not impair the effects of the present invention.

The external preparation for skin of the present invention can be produced by a conventional method. For example, in the case of an emulsion, an aqueous phase component,
It is produced by mixing an oil phase component and an emulsifier and emulsifying them.

[0018]

The external preparation for skin of the present invention has good stability,
It has a good feeling of use, has no irritation to the skin, and has excellent moisturizing action, keratin softening action, antipruritic action and anti-inflammatory action, and is extremely useful for the treatment of cutaneous keratosis and dry pruritus dermatitis. .

[0019]

EXAMPLES Next, the present invention will be further described with reference to examples, but the present invention is not limited to these examples.

[0020]

Table 1 Example 1 (Component) Urea 10 (%) Glycyrrhetinic acid (average particle size 20 μm) 0.3 White petrolatum 1.0 Squalane 9 Carboxyvinyl polymer (Hibis Wako, Wako Pure Chemical Industries, Ltd.) 0.2 Stearin Acid 1.5 Glycerin monostearate 1.0 Polyoxyethylene sorbitan monostearate 1.5 Polyoxyethylene (60) hydrogenated castor oil 0.5 Potassium dihydrogen phosphate 0.5 Sodium hydroxide Proper amount of water Remaining amount

(Production Method) (1) The aqueous phase component, urea, sodium dihydrogen phosphate, sodium hydroxide and carboxyvinyl polymer are dissolved in water and heated to 75 ° C. (2) The oil phase components (all remaining components) are dissolved by heating and kept at 75 ° C. (3) (1) and (2) were mixed and stirred with a homomixer under reduced pressure to produce an emulsion lotion.

[0022]

Table 2 Example 2 (Component) Urea 20 (%) Glycyrrhetinic acid (average particle size 30 μm) 0.3 White petrolatum 15 Squalane 6 Glycerin monostearate 1.2 Polyoxyethylene sorbitan monostearate 1.4 Polyoxy Ethylene (50) hydrogenated castor oil 0.5 potassium dihydrogen phosphate 0.5 sodium hydroxide appropriate amount of water remaining amount

(Production method) A cream was produced in the same manner as in Example 1.

[0024]

Comparative Example (Component) Urea 10 (%) White petrolatum 20 Squalane 6 Cetanol 3 Stearyl alcohol 3 Polyoxyethylene (50) hydrogenated castor oil 0.5 Sorbitan monostearate 0.9 Polyoxyethylene sorbitan monostearate 1.5 Potassium dihydrogen phosphate Water in appropriate amount

(Production Method) A cream was produced in the same manner as in Example 1.

Test Example The external preparations obtained in Example 1 and Comparative Example were examined for improvement in various diseases. The results are shown in Figures 1 and 2. (Test method) A total of 66 outpatients at 3 centers were externally applied to the affected area simply by applying the external preparation 2 to 3 times a day, and the skin findings at the end of administration were compared with those before treatment, and the degree of improvement was tabulated. The rate was more than moderate improvement. The degree of improvement was based on the following criteria. Healing, marked improvement, moderate improvement, mild improvement, unchanged, worse

As is clear from the results of FIGS. 1 and 2, it was confirmed that the external preparation for skin of the present invention has an extremely excellent therapeutic effect on keratoderma keratosis and pruritus dermatitis dermatosum. In particular, it is useful for treating dry skin of children, xeroderma of the aged, rash skin, etc. The stability was good, the feeling of use was good, and no irritation to the skin was observed.

[Brief description of drawings]

FIG. 1 is a diagram showing an improvement rate of clinical effects by disease in a test example.

FIG. 2 is a diagram showing the improvement rate of clinical effects by symptoms in test examples.

Claims (3)

[Claims] 1. A skin external preparation containing urea and glycyrrhetinic acid as active ingredients. 2. Skin according to claim 1, containing 8 to 25% by weight of urea, 0.1 to 0.5% by weight of glycyrrhetinic acid, 0.1 to 4.0% by weight of emulsifier and 40 to 80% by weight of water. Topical agent. 3. The average particle size of glycyrrhetinic acid is 40 μm.
The external preparation for skin according to claim 1 or 2, which is m or less.