JPH05271517A - Polymer gel composition - Google Patents

Abstract

PURPOSE:To obtain a polymer gel composition having excellent chemical characteristics and stability with time, applicable in fields of medical material, quasi-drug, cosmetic, medicine, etc. CONSTITUTION:This polymer gel composition comprises a copolymer of N- vinylacetamide and acrylic acid and/or acrylate, an epoxy compound and a wetting agent as essential components. The copolymer is a copolymer of N- vinylacetamide and acrylic acid and/or acrylate monomer (monomer weight ratio=99:1 to 1:99). An alkali metal acrylate such as sodium, lithium or potassium acrylate is preferable as the acrylate. An epoxy compound is suitable as a crosslinking agent for the copolymer and the copolymer is insolubilized by crosslinking. Water or an alcohol can be used alone or mixed and used as the wetting agent. The preferable amount of the crosslinking agent blended is 0.01-5 pts.wt., more preferably 0.1-3 pts.wt. based on 10 pts.wt. copolymer.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a therapeutic pad, a pressure ulcer preventive agent, a heat insulating material, a cold insulating material, a wound protective agent, a pack agent, a patch agent,
The present invention relates to a polymer gel composition used as a drug sustained release agent.

[0002]

2. Description of the Related Art Conventionally, natural polymers or natural polymer derivatives such as gelatin, sodium alginate, carboxymethylcellulose and starch, and synthetic polymers such as polyvinyl alcohol, sodium polyacrylate, polyvinylpyrrolidone and carboxyvinyl polymer have been used. Polymer gels have been widely used in various applications as therapeutic pads, pressure ulcer preventives, heat insulating materials, cold insulating materials, wound protective agents, packs, patches, and drug sustained-release agents.

For example, JP-A-59-93012 discloses a hydrogel obtained by metal-crosslinking with sodium polyacrylate, and JP-A-61-106603 discloses a hydrogel obtained by metal polymerization of acrylic acid. No. 26663 discloses an aqueous gel obtained by crosslinking polyvinyl alcohol with glutaraldehyde, and JP-A No. 1-297484 discloses an aqueous gel obtained by a reaction between gelatin and a maleic anhydride copolymer.

[0004]

DISCLOSURE OF THE INVENTION The present invention has the problems that conventional polymer gels have, that is, weak gel strength,
There are problems such that water can be relatively easily removed and initial properties are not retained, pH is unstable with respect to electrolytes, and stability over time is lacking. Therefore, the present inventors have conducted various studies for the purpose of solving the above-mentioned problems, and as a result, have found a polymer gel composition having novel and excellent chemical stability properties and completed the present invention. Just

[0005]

DISCLOSURE OF THE INVENTION The present invention is a novel polymer gel comprising a copolymer of N-vinylacetamide and acrylic acid and / or acrylic acid salt, an epoxy compound and a wetting agent as essential components. It is a composition.

The copolymer used in the present invention is a copolymer of N-vinylacetamide and acrylic acid and / or acrylate monomer (monomer weight ratio = 99: 1 to 1: 1).
99). Further, as the acrylate salt, alkali metals such as sodium, lithium and potassium are preferable.

Epoxy compounds are suitable as a crosslinking agent for these copolymers and are insolubilized by crosslinking. For example, as the epoxy compound, polyethylene glycol diglycidyl ether, ethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, propylene glycol diglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, sorbitan polyglycidyl ether. , Trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether, resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether,
Examples include bisphenol type epoxy resin.

The preferred blending amount of these crosslinking agents is 0.01 to 5 parts by weight, more preferably 0.1 to 3 parts by weight, based on 10 parts by weight of the copolymer. If the compounding amount of the cross-linking agent deviates from this range, there arises a problem that the cohesiveness and shape retention are lowered, or the cross-linking density becomes high and gelation progresses during the production.

Further, the wetting agent used in the present invention is used as a plasticizer for dispersing / dissolving the above copolymer. As the wetting agent, water or alcohol can be used alone or as a mixture. Examples of the alcohol include monohydric alcohols such as methanol, ethanol, propanol, isopropanol, butanol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1.3-butylene glycol, and 1. Polyhydric alcohols such as 4-butylene glycol, isobutylene glycol, glycerin, diglycerin and sorbitol can be used.

A preferable blending ratio (weight ratio) of the wetting agent and the copolymer is 10: 0.1-10, more preferably,
10: 0.5 to 5 parts by weight. If the compounding ratio of the both exceeds this range, there is a problem that the shape retention property, the cohesive force, and the workability deteriorate.

The polymer gel composition of the present invention contains, in addition to the above-mentioned essential components consisting of a copolymer, an epoxy compound and a wetting agent, a conventionally known pH adjusting agent, antioxidant, tackifier and preservative. Compounding agents such as a solubilizer, a drug, a fragrance, a surfactant, an ultraviolet absorber, an absorption promoter, and an inorganic filler are appropriately mixed in appropriate amounts.

Next, as a method for producing the polymer gel composition of the present invention, the copolymer and the wetting agent are dispersed / dissolved in a stirrer, and then an epoxy compound is added / mixed to enhance the composition. Use molecular gel. Gelation proceeds within a few days, but can be shortened to a few hours by heat treatment.

[0013]

The polymer gel composition of the present invention has the following excellent features. a. Good shape retention and high gel strength. b. There is no separation of water and the initial characteristics are maintained. c. It is stable to pH and electrolytes. d. It is resistant to temperature changes and has excellent stability over time. e. It can be used as a base for holding drugs and fragrances. f. Since it is less irritating to the skin and has a suitable adhesiveness, it can be directly applied to the human body.

[0014]

EXAMPLES The present invention will be described in more detail below with reference to examples and test examples.

Example 1 10 parts by weight of N-vinylacetamide / sodium acrylate copolymer (monomer weight ratio: 70:30) and 86 parts by weight of purified water were mixed and dissolved, and then 4 parts by weight of ethylene glycol diglycidyl ether. Was added, and the mixture was mixed until it became uniform to obtain a transparent polymer gel composition.

Example 2 10 parts by weight of N-vinylacetamide / sodium acrylate copolymer (monomer weight ratio; 95: 5) were mixed and dissolved in 60 parts by weight of glycerin and 28 parts by weight of ethanol, and then neopentyl diglycidyl was added. 2 parts by weight of ether was added and further mixed until uniform to obtain a transparent polymer gel composition.

Example 3 15 parts by weight of an N-vinylacetamide / sodium acrylate copolymer (monomer weight ratio: 90:10) and 30 parts by weight of glycerin were mixed and dissolved in 54.8 parts by weight of purified water, and thereafter. 0.2 parts by weight of trimethylolpropane polyglycidyl ether were added and mixed until uniform. This composition was heat-treated at 50 ° C. for 5 hours to obtain a transparent polymer gel composition.

Example 4 5 parts by weight of N-vinylacetamide / sodium acrylate copolymer (monomer weight ratio: 80:20) and 64 parts by weight of glycerin were mixed and dissolved in 30 parts by weight of purified water, and then penta Erythritol polyglycidyl ether 1
Parts by weight were added and further mixed until uniform to obtain a transparent polymer gel composition.

Comparative Example 1 6 parts of polyacrylic acid having an average degree of polymerization of 20,000 and 30 parts of glycerin were mixed and dissolved in 52 parts of purified water. afterwards,
An aqueous solution of 2 parts of aluminum lactate and 10 parts of purified water was added and further mixed until uniform to obtain a transparent polymer gel composition.

Comparative Example 2 5 parts of gelatin was dissolved in 72 parts of purified water heated to 60 ° C., and then a mixture of 3 parts of polyvinyl alcohol having an average degree of polymerization of 2000 and 20 parts of glycerin was added, and the mixture was further homogenized. It was stirred. This mixture was cooled to 5 ° C. to obtain a transparent polymer gel composition.

Test Examples The polymer gels obtained in Examples 1 to 4 and Comparative Examples 1 to 2 were subjected to the following tests and shown in Table 1.

1) Shape retention of gel The sample was left at room temperature for 7 days and the fluidity of the gel was observed. ○: Good shape retention △: Slight flow ×: Flow (no shape retention)

2) Gel swelling test 1 g of the sample was put in 500 ml of purified water and the state of the gel was observed. ○: Swelling △: Swelling to dissolution ×: Dissolution

3) Stability of gel The sample was allowed to stand at 40 ° C. for 7 days and then returned to room temperature to observe its properties. ◯: Good shape retention Δ: Water is released and the shape retention is partially lost. ×: No shape retention

[0025]

[Table 1]

As shown in Table 1, the polymer gel compositions of Examples 1 to 4 have better shape retention than the hydrogels of Comparative Examples 1 and 2 and should dissolve in purified water. It was also excellent in stability.

[0027]

INDUSTRIAL APPLICABILITY As described above, the polymer gel composition of the present invention has excellent chemical properties and stability over time and is applicable to the human body. Therefore, it is used as a medical material, a quasi drug, a cosmetic, a drug. It can be applied in each field such as. Especially, among them, therapeutic pad, pressure ulcer preventive agent, heat insulation material, cold insulation material, wound protection agent,
It can be used as a pack, patch, sustained-release drug, etc., and is extremely useful industrially.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhisa Furuse 408, Tashiro Daikanmachi, Tosu City, Saga Prefecture Hisamitsu Pharmaceutical Co., Ltd.

Claims (1)

[Claims] 1. A polymer gel composition containing an epoxy compound and a wetting agent as essential components in a copolymer of N-vinylacetamide and acrylic acid and / or acrylic acid salt.