JPH02311414A - Skin drug for external use - Google Patents

Abstract

PURPOSE:To obtain a skin drug for external use, excellent in softening action on the skin and good in adhesion thereto and washing and removal thereof by emulsifying a solvent, an oily agent containing nitrocellulose, and an aqueous solution containing a water-soluble polymer into a water-in-oil type emulsion. CONSTITUTION:The objective substance obtained by blending an oily agent containing nitrocellulose and a solvent with an aqueous solution of a water-soluble polymer in the form of a water-in-oil(W/O) type emulsion, using the resultant emulsion as an essential ingredient and further suitably adding a resin, plasticizer, humectant, disinfectant, germicide, analgesic agent, anti-inflammatory agent, antihistaminic agent, vitamic agent, etc., thereto and preparing a pharmaceutical. The nitrocellulose having 30% wettability with isopropyl alcohol is normally blended in an amount of 5 to 25wt.% and the solvent is blended in an amount of 30 to 85wt.%. The water-soluble polymer is blended as an aqueous solution in an amount of 0.5 to 30wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a skin preparation for external use that has an improved softening effect on the skin.

[Prior Art and its Problems] Skin protective agents for protecting the skin from drugs and other irritating substances have been generally known.

This skin protectant protects the skin by applying a solution containing a film-forming agent that is compatible with the skin to the skin to form a protective film. dermatitis on the fingers, prickles,
BACKGROUND OF THE INVENTION External preparations for covering and protecting the affected area are widely used to treat nail wounds, cuts, abrasions, chaps, cracks, and the like.

As such external preparations, for example, a solution of nitrocellulose called collodion dissolved in a mixture of ether and ethanol has been known for a long time.

However, the adhesion of the collodion film to the skin is insufficient, and there is a drawback that it is easily peeled off due to bending during use, wetting with water, etc. As an improved product, elastic collodion has been developed by adding mustard oil to collodion.
The addition of castor oil increases the hydrophobicity of the composition, making it easy to peel off even if there is a small amount of moisture on the skin surface. In addition, nitrocellulose is insoluble in water and oil, so
Once adhered strongly to the skin, there are problems such as that it cannot be removed without using a special removal solution such as lacquer thinner or enamel remover.

On the other hand, for the purpose of improving skin keratin, it is used to treat rough heels, corns, and corns.
Salicylic acid ointment has been known for a long time as a drug for dissolving and removing calluses, etc., but it lacks quick drying properties and has problems in terms of usability, such as being sticky. In addition, solvent-based salicylic acid preparations lack hydration to the affected area and cause irritation such as ``tingling'' and ``stinging''.

[Means for Solving the Problems] As a result of intensive research in order to solve the conventional problems as described above, the present inventors have developed an aqueous solution of a water-soluble polymer in an oil-based agent containing nitrocellulose and a solvent. We have discovered that if a specific amount of W10 is blended in the form of an emulsion, a skin preparation for external use can be obtained that has excellent softening effects on the skin, has excellent adhesion to the skin, and is easy to clean and remove.
Based on this knowledge, we have completed the present invention.

That is, the present invention uses an oil-based agent containing nitrocellulose and a solvent, and an aqueous solution or water-in-oil (W) containing a water-soluble polymer.
/O type) is an emulsified product for external use on the skin.

Hereinafter, the configuration of the present invention will be explained in detail.

As the water-soluble polymer, cellulose-based, acrylic-based, vinyl-based, polyamide-based, protein-based, etc. can be used. For example, hydroxyethylcellulose (Natrozol 0250LR1 American Vercules, etc.), hydroxypropyl methylcellulose (Metrose" TC-5
, Shin-Etsu Chemical, etc.), methacrylic acid ester amphoteric polymers (Yukaformer AM-75W, WH1 Mitsubishi Yuka, etc.), polyacrylic acid Na (Aron" A-20p, Toagosei Chemical, etc.), polyvinyl alcohol Honsei Kagaku Kogyo, etc. ), methyl vinyl ether/maleic anhydride copolymer (Gantrez AN-119, General Aniline, etc.), polyethylene oxide (PEO
-1, Steel Chemical Industry, etc.), α-(N-dimethylamino)-ε-prolactam ε-caprolactam copolymerized modified nylon (AQ-nylon 0, Toshi, etc.), casein N
a, gelatin, hyaluronic acid or its salts (molecular weight 1
10,000 to 2,200,000).

The amount of water-soluble polymer blended is W in the form of a water-soluble polymer aqueous solution.
It is sufficient that the internal phase of the skin external preparation is emulsified in /O type, and is preferably 0.5 to 30% by weight (hereinafter simply %) in the form of a water-soluble polymer aqueous solution, although it is not particularly limited. ), particularly preferably from 1 to 25%. If the amount of the water-soluble polymer aqueous solution blended is too small, a sufficient softening effect on the skin cannot be expected, while if it is too large, the adhesion to the skin will decrease and "sagging" will be observed, which is not preferable. Roughly speaking, water-soluble polymers are 0.0% relative to water.
It is preferably selected in the range of 3 to 20%, more preferably 0.5 to 15%. If the amount of water-soluble polymer blended is too small, the separation stability of the W10 emulsion system tends to deteriorate.
On the other hand, if the amount is too high, usability such as "stickiness" tends to be poor.

As the nitrocellulose used in the present invention, any conventionally known nitrocellulose can be used. for example,
Examples include nitrocellulose 1/4 second, nitrocellulose 1/2 second, nitrocellulose 2 seconds, nitrocellulose 7 seconds, and nitrocellulose 20 seconds. One or more types are arbitrarily selected from these.

The blending amount is generally 5 to 25% with an IPA (isopropyl alcohol) wetness of 30%.

As the solvent used in the present invention, conventionally known ester-based, alcohol-based, and hydrocarbon-based solvents can be used. For example, ethyl acetate, butyl acetate,
Examples include amyl acetate, ethyl alcohol, isopropyl alcohol, butyl alcohol, and toluene. One or more types are arbitrarily selected from these.

The blending amount is generally 30 to 85%.

In addition to the above-mentioned essential ingredients, the skin external preparation of the present invention may contain resins, plasticizers, humectants, etc., as necessary.

In addition, disinfectants, bactericidal agents, analgesics, anti-inflammatory agents,
Antihistamines, vitamins, and other additives may also be included. For example, a bactericidal agent such as isopropylmethylphenol is effective in preventing bactericidal contamination or extinguishing inflammation caused by contamination when the topical preparation is applied to a wound. Cracks in hands caused by water work, etc.
Applying the external preparation of the present invention containing a bactericide to chapped wounds will prevent deterioration and at the same time promote healing of the wound surface. At this time, if a drug having peripheral vasodilatory action and antihistamine action, such as tocopherol acetate or ascorbic acid, is added to this external preparation, it can be expected to be effective in preventing and treating frostbite.

Similarly, this topical preparation contains substances with keratolytic action, such as salicylic acid, urea, lactic acid, amino acids, pyrrolidone carboxylic acid, and one or more surfactants alone or in combination. Since the substance contained in the film acts continuously on keratinized skin over a long period of time, it has a remarkable effect on the treatment of calluses and corns.

(The following is a blank space) [Example] Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. Note that the present invention is not limited to this. The blending amount is in weight%.

Examples 1 and 2, Comparative Example 1.2 External skin preparations were manufactured using the ingredients and amounts listed in Table 1. Each manufacturing method is as follows.

(Production method of Examples 1 and 2) To a mixture of (1), (2), and (2), (1), (2), and (2) are added and dissolved with stirring. Next, (1) and (2) were added and uniformly stirred (emulsified) to obtain the desired formulation.

(Production method of Comparative Example 1) ■ and ■ were added to a mixture of ■, ■, and ■, and the mixture was stirred and dissolved to obtain the desired formulation.

(Production method of Comparative Example 2) (2) was added to (2), and the mixture was stirred and dissolved to obtain the desired formulation.

Table 1 "HPMC: Hydroxypropyl Methyl Cellulose") IPA wettability 30% Evaluation of emollient effect In order to evaluate the emollient effect, the stratum corneum was collected from guinea pigs. That is, the hair of the guinea pig is removed using clippers, a depilatory agent, etc., and after the erythema has subsided, the skin layer is peeled off using scissors. After peeling, the subcutaneous fat is excised with scissors, then immersed in warm water at 60°C for 1 minute, cooled in water, and the epidermis is peeled cleanly with tweezers. The epidermis was soaked in a 0.1% trypsin solution (buffer pH 7,8 > 37°
C- Treat for 30 minutes to digest living cells and obtain stratum corneum.

The stratum corneum was washed with water, dried, and used for testing. The stratum corneum was cut into a 2° x 3 mm section, each sample of Example 1.2 and Comparative Examples 1 and 2 was coated on it, and the stratum corneum was measured using a continuous dynamic viscoelasticity meter at 25°C and 50% RH. The flexibility of the material was measured.

Figure 1 shows the softening effect of the stratum corneum, the dynamic viscoelastic modulus (
E-) and the time-dependent dynamic viscoelastic modulus after treatment 1 = 0 (E-1).The dynamic viscoelastic modulus is the ratio of the force required to collect and stretch the stratum corneum. The softer the stratum corneum, the lower the dynamic viscoelastic modulus.

As is clear from the figure, the formulations of Examples containing water had significantly better softening effects than Comparative Examples.

Examples 3 to 8, Comparative Example 3 External skin preparations were manufactured using the ingredients and amounts listed in Table 2. Each manufacturing method is as follows.

(Manufacturing method of Comparative Example 3) ■ and ■ were added to the mixture of ■ and ◎, and the mixture was stirred and dissolved. Next, (1) and (2) were added and uniformly stirred (emulsified) to obtain the desired formulation.

(Production method of Examples 3 to 8) To a mixture of (1) and (0), (1) and (2) were added and dissolved with stirring. Next, any one of ■ to ■ and ■ were added and uniformly stirred (emulsified) to obtain the desired formulation.

(Hereinafter, blank space) Each of the above compositions was tested for separation (emulsification) stability, ease of application (relaxation), and irritation during application. Tests and evaluations were conducted as follows.

Separation (emulsification) stability Each sample was packed into two 50 d Laspin tubes,
These were left at room temperature and 50° C. for one week, and the state of each separation was evaluated. The evaluation is as follows.

◎ (Good)...Both were not separated at all ○(Slightly good)...One or both were slightly separated △(Slightly poor)...One or both were separated × ( Poor)...either one or both of the coatings are very separated. Drop 2 ml of each sample onto the center of the slide glass, and after 1 minute, tilt the slide glass at 45° to check the extent of each drip. was evaluated.

◎ (Good)... No dripping was observed at all ○ (Good)... Dragging was observed, but it remained on the slide glass ∆ (Slightly poor)... It slowly ran down (Poor)...Irritation when applied (stinging sensation) as it quickly ran down. Fill a glass bottle with a 107 brush with the sample, apply an appropriate amount to the back of the hand using a panel of 20 people, and evaluate the stinging sensation. did. Evaluation was performed as follows according to the number of panels that felt stimulation.

Number of panels that felt irritation ◎ (good) 0 to 5 people O (slightly good) 6 to 10 people △ (slightly bad) 11 to 15 people X (poor) 16 to 20 people It is shown in Table 3.

Table 3 Example 9 ■Purified water 15. O
■Concentrated glycerin 3.0 ■Urea 2.
0 ■ Polyvinyl alcohol 2.0 ■ Nitrocellulose HIG-20s.

(, IPA wetness 30%) ■ Isopropyl alcohol 3.0 ■ Tocopherol acetate 1.0 ■ Isopropyl methylphenol 0.1 ■ Triethyl citrate
2.0 [stock] ethyl acetate
Stir and mix the remaining ■, ■, ■, [stock], and add ■ to this.
, ■ and stir to dissolve. Next, to this one, ■
Add ■ and ■ to the solution of ■,
The desired formulation was obtained by uniformly stirring (emulsifying). The obtained formulation had good separation stability, ease of application, and irritation during application.

Example 10 ■ Purified water 20. O
■1,3-butylene glycol 4.0■Dodecyldimethylamine oxide 0.2■Sodium dodecyl sulfate 0.06■Hydroxyethylcellulose 2.0■n-butyl alcohol 3°40■Nitrocellulose RIG-71o.

(IPA humidity 30%) ■Castor oil 3
．． 0 ■Butyl acetic acid Remainder■,■
, ■ are stirred and mixed, and ■ is added thereto, and stirred and dissolved.

Then, to this one, ■ to ■, ■.

A stirred and dissolved solution of (1) and (2) was added and uniformly stirred (emulsified) to obtain the desired formulation. The obtained formulation is.

Separation stability, ease of application, and irritation during application were all good.

[Effects of the Invention] As explained above, the skin external preparation of the present invention has an excellent softening effect on the skin by incorporating water, and also has excellent adhesion to the skin and ease of removal after use. It is something. Therefore, it can be widely used as a variety of skin protectants and exfoliants.

[Brief explanation of drawings]

FIG. 1 is a characteristic diagram showing temporal changes in the dynamic viscoelastic gravity ratio of the stratum corneum using an example of the present invention, together with a comparative example. Applicant: Shiseido E't Co., Ltd.
E"t= . group -1%CI-1

Claims (1)

[Claims] (1) An external preparation for skin, characterized in that an oil-based agent containing nitrocellulose and a solvent and an aqueous solution containing a water-soluble polymer are emulsified into a water-in-oil type (W/O type).