JPH06315525A - Water-absorptive polymer laminate for medical use and coating material for wound by using the same - Google Patents

Abstract

PURPOSE:To absorb exudates without pressing a wound part by forming the water absorptive polymer laminate to be used for the coating material for wounds, etc., of two kinds of water absorptive polymers varying in water absorbability and forming the low water absorptive polymer layer of these layers as a layer to be touched on the skin. CONSTITUTION:This water absorptive polymer laminate adequate for use with the coating material for wounds is formed by laminating two kinds of the water absorptive polymers varying in the water absorbability, i.e., the sheets or films of the high water absorptive polymer and the low water absorptive polymer. The low water absorptive polymer sheet of these layers is formed as the layer to be in direct contact with the water, such as exudates, i.e., the layer to be touched on the skin. The low water absorptive polymer layer of the coating material for wounds formed by using such water absorptive polymer laminate first swells slightly by absorbing the water, then the water migrates to the high water absorptive polymer layer and this layer swells. Namely, the polymer layers swell in the direction parting from the wound surface and, therefore, the wound part is not pressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-absorbent polymer laminate for medical use, and more particularly to a wound dressing made of a laminate of two kinds of water-absorbent polymers having different water absorbing capacities.

[0002]

2. Description of the Related Art A number of research results have been reported on the treatment of skin wounds such as burns, skin-wounds, traumatic skin defect wounds, and pressure sores, but the wounds can be moistened without being immersed in water. By maintaining and preventing microbial contamination, healing is promoted without forming crusts, so-called W
et Healing (RG Geronemus, et al., J. Derm
atol. Surg. Oncol. , 8 (10), 850 (1982)), the expectation is increasing year by year.

Among the wound dressings used for Wet Healing, those having water-absorption swelling properties such as hydrocolloid dressings and hydrogel dressings have been proposed.

[0004]

The hydrocolloid dressing, the hydrogel dressing, and the like having water-absorbing expansivity partially increase in volume due to absorption of the exudate. That is, the thickness of the liquid absorbing portion may increase or deform depending on the amount of liquid absorbed, and the wound may be compressed.

As described above, when the wound area is compressed, angiogenesis, migration and proliferation of fibroblasts and epidermal cells are suppressed or inhibited, and a sufficient healing effect may not be obtained in some cases. In this respect, the material having a porous form retains water in the voids, so that the swelling due to liquid absorption is small. However, since the porosity requires complicated manufacturing steps, industrial mass production is extremely difficult.

The present invention was completed in view of the above technical problems, and is a laminate of two kinds of water-absorbing polymers having different water-absorbing capacities, and the low water-absorbing polymer layer is a skin-adhesion layer. Thus, it is an object of the present invention to provide a medical-use water-absorbing polymer laminate capable of absorbing exudate without pressing the wound part and a wound dressing using the same.

[0007]

In order to achieve the above object, a medical water-absorbent polymer laminate of the present invention is a laminate of two water-absorbent polymers having different water-absorbing capacities, and a low water-absorbent polymer layer. Is a laminate of a water-absorbent polymer film or sheet which is a skin-adhesive layer.

Further, the wound dressing of the present invention comprises the medical water-absorbing polymer laminate of the present invention in order to achieve the above object.

The present invention will be described in detail below. The medical water-absorbent polymer laminate of the present invention is obtained by laminating sheets or films of two kinds of water-absorbent polymers having different water-absorbing capacities, that is, a super-water-absorbent polymer and a low-water-absorbent polymer. The polymer layer is a layer that comes into direct contact with water such as exudate, that is, a skin-adhesion layer.

When the wound surface in which serum or the like is leached is coated with the medical water-absorbing polymer laminate of the present invention, the low water-absorbing polymer layer first absorbs water and slightly swells, and then the water absorbs high water. The polymer layer swells and swells, but for the reason described below, the polymer layer swells in the direction away from the wound surface, and at least does not press the wound site. Therefore, the wound is not subjected to physical pressure, and the gelled water-absorbent polymer layer maintains a moist environment suitable for wound healing.

For the medical water-absorbent polymer laminate of the present invention, any water-absorbent polymer composition used for medical purposes can be used. That is, it is a water-absorbing polymer composition having excellent skin irritation, safety and stability, and can be formed into a sheet or a film.

In the present invention, the water-absorbent polymer composition means a water-soluble polymer substance insolubilized by crosslinking or an uncrosslinked water-absorbent polymer substance, and an additive such as a humectant or a plasticizer added thereto. It is a thing.

The water-soluble polymer substance is not particularly limited as long as it is a polymer that absorbs water,
Specifically, for example, gelatin, polyvinyl alcohol,
Methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, sodium alginate, polyvinylpyrrolidone, polyvinyl methyl ether, pectin, polyethylene oxide, hyaluronic acid, sodium hyaluronate, polyacrylamide, polyacrylic acid, sodium polyacrylate, or other than these A hydrophilic acrylic polymer can be used.

Further, as the uncrosslinked water-absorbing polymer substance,
Examples thereof include those having the same composition as the above-mentioned water-soluble polymer and having an ultra-high molecular weight or intricately entangled with each other, which absorbs water and swells in an uncrosslinked state but is insoluble in water.

On the other hand, examples of the additives include glycerin, sorbitol, maltitol, ethylene glycol, diethylene glycol, polyethylene glycol,
Propylene glycol, polypropylene glycol,
Examples include 1,3-butylene glycol, polyoxypropylene glycol, and polyoxypropylene sorbitol.

By the way, in the present invention, if desired, other drugs such as an antibacterial agent and a healing promoting substance may be appropriately contained.

The medical water-absorbent polymer laminate of the present invention is obtained by adhering two kinds of sheets or films selected from the above-mentioned water-absorbent polymer compositions and having different water-absorbing capacities to such an extent that delamination does not occur during water-swelling. To be As an adhesion method, any method may be used as long as it sufficiently transfers water between the two layers and does not hinder the expansion due to swelling, such as a fusion bonding method, a thermocompression bonding method, an adhesive method and a radiation method.
(Electron beam, γ-ray) and the like can be mentioned.

The superabsorbent polymer layer and the low absorbency polymer layer constituting the medical water-absorbent polymer laminate of the present invention may be the same or similar or different types as long as the two can be sufficiently adhered. Any combination of materials may be used, but materials having a high degree of similarity are preferred because they are more easily bonded.

Further, the larger the difference between the water absorption capacities of the two polymers, the more the tendency of deforming and swelling in a convex shape increases, and the possibility of pressing the wound area decreases, which is preferable. At this time, the low water-absorbent polymer layer that is in direct contact with water is required to immediately transfer absorbed water to the super-water-absorbent polymer layer, and to maintain a wet environment suitable for wound healing in a gel state. Water absorption capacity and water permeability above a certain level are required.

That is, regarding the water absorption capacity of the low water-absorbent polymer, it is desirable that the water absorption rate (the measuring method will be described later) is 50% or more, preferably 100% or more, more preferably 200% or more. At this time, the water absorption capacity of the super absorbent polymer is
Water absorption (measurement method described later) is higher than that of the low water-absorbing polymer, preferably 2 times or more that of the low water-absorbing polymer, more preferably 3 times or more of that of the low water-absorbing polymer, and water absorption rate at the time of water absorption When it is 5,000% or less, it is desirable that a gel state having substantially usable strength be obtained.

Further, in order to obtain sufficient water permeability, the thickness of the low water-absorbent polymer layer is limited, that is, it is preferably equal to or less than the thickness of the high water-absorbent polymer layer, and more preferably high. It is desirable that the amount is 1/2 or less of the water-absorbent polymer.

In the present invention, the total thickness of the super absorbent polymer layer and the low absorbent polymer layer is preferably 10 μm or more, particularly 100 μm or more and 5 mm or less, and more preferably 500 μm or more and 2 mm or less. If the thickness is less than 10 μm, the amount of the exudate absorbed is small and the exudate stays between the skin and the low water-absorbent polymer layer, resulting in unsanitary condition.
Strongly, there is a problem such as causing infection due to leakage of exudate, on the other hand, if it exceeds 5 mm, it is not possible to follow the expansion and contraction of the skin, the usability deteriorates, and bacteria etc. invade from the concave part caused by the bending of the skin, Not desirable for reasons such as causing infection.

The wound dressing of the present invention is formed by using the above-mentioned medical water-absorbent polymer laminate, and comprises two types of water-absorbing polymers having a low water-absorbing polymer layer as a skin-adhering layer and having different water-absorbing capacities. Since it is made of a laminate of water-soluble polymer, it swells and deforms outwardly when it absorbs water. As a result, it is an excellent wound coating that allows wound healing in a moderately moist environment without pressing the wound area. It becomes a material.

In the present invention, the water absorption rate is obtained by the following method. That is, each sample was 1.5 cm x 1.
After cutting into 5 cm and measuring the weight before absorbing water, each cut piece was immersed in 135 ml of phosphate buffered saline (pH 7.4, 32 ° C.) for 24 hours. After that, each cut piece was taken out, the surface water was wiped off, the weight after water absorption was measured, and the water absorption rate was calculated from the increased weight.

[0025]

The present invention has the above-mentioned constitution, and when the wound surface in which serum or the like is leached is coated with the composition, first, the low water-absorbing polymer layer absorbs water and slightly swells, and then the water content Migrates to the super absorbent polymer layer and participates in swelling.

Here, since the high water-absorbent polymer layer and the low water-absorbent polymer layer adhere to each other with sufficient strength even after absorbing water, and there is a difference in the degree of swelling, at any time when the water content is in an equilibrium state, A force acts in a direction in which the water-absorbent polymer layer side swells in a shape that is convex outwardly, that is, the polymer layer swells in a direction away from the wound surface, so that at least the wound portion is not pressed. Therefore, the wound has a function of maintaining a moist environment suitable for wound healing by the gelled water-absorbent polymer layer without being physically pressed.

[0027]

EXAMPLES The present invention will be described below based on examples, but the present invention is not limited thereto. Example 1 30 parts by weight of N-vinyl-2-pyrrolidone and 70 parts by weight of 2-methoxyethyl acrylate were polymerized in toluene in the presence of azobisisobutyronitrile to obtain an acrylic resin having an average molecular weight of 25,000. Copolymer thickness 400μm
Was formed into a film shape to obtain a super absorbent polymer layer.

On the other hand, 20 parts by weight of N-vinyl-2-pyrrolidone and 80 parts by weight of 2-methoxyethyl acrylate were polymerized in toluene in the presence of azobisisobutyronitrile to give an average molecular weight of 166,000. The acrylic copolymer was molded into a film having a thickness of 100 μm to form a low water-absorbent polymer layer.

These two types of polymer layers were pressure-bonded at room temperature and then crosslinked by irradiation with γ-rays (dose of 20.7 kGy to 21.8 kGy) to obtain a medical water-absorbing polymer laminate of the present invention.

The water absorption rate of the medical water-absorbing polymer after γ-ray irradiation was 1100% for the high water-absorbing polymer layer and 500% for the low water-absorbing polymer layer.

The resulting medical-use water-absorbing polymer laminate was mixed with 5
The wound dressing material of the present invention was obtained by cutting into cm × 5 cm square.

Comparative Example 1 30 parts by weight of N-vinyl-2-pyrrolidone and 70 parts by weight of 2-methoxyethyl acrylate were polymerized in toluene in the presence of azobisisobutyronitrile to obtain an average molecular weight of 25,000. Acrylic copolymer of 500μm thick
After being formed into a film, the gamma ray (dose 20.7 kGy ~
21.8 kGy) Crosslinked by irradiation, water absorption is 1100%
A water absorbent polymer sheet of was obtained. This was cut into 5 cm × 5 cm squares to obtain a wound dressing.

Water Absorption Test The wound dressings obtained in Example 1 and Comparative Example 1 were placed on the floor so that the low water-absorbent polymer layer (any surface in Comparative Example 1) faced upward, Distilled water (about 1
g) was added dropwise and the water absorption and swelling behavior was observed and compared.

As a result, in the dressing for wound of Example 1, the water absorption site swelled outwardly in a convex shape, and the peripheral edge portion floated up from the peelable film. On the other hand, in the wound dressing of Comparative Example 1, the water absorption site swelled in a concave shape, and the center part thereof floated up from the peelable film. Considering the case of being applied to an actual wound site from these behaviors, it is estimated that the wound dressing of Example 1 swells in the non-compression direction and the wound dressing of Comparative Example 1 swells in the compression direction. It

The water absorption is determined by the following method. That is, each sample was cut into 1.5 cm × 1.5 cm, the weight before water absorption was measured, and each cut piece was immersed in 135 ml of phosphate buffered saline (pH 7.4, 32 ° C.) for 24 hours. . After that, each cut piece was taken out, the surface water was wiped off, the weight after water absorption was measured, and the water absorption rate was calculated from the increased weight.

[0036]

Industrial Applicability The medical water-absorbent polymer laminate of the present invention has the above-mentioned constitution, and is a laminate of two kinds of water-absorbent polymers having different water-absorbing capacities in which the low water-absorbent polymer layer is the skin-adhering layer. Therefore, when water is absorbed, the super absorbent polymer layer side is deformed and swelled in the outward convex direction,
This allows wound healing in a moderately moist environment without pressing the wound.

Therefore, the wound dressing formed by using this medical water-absorbent polymer laminate is easy to manufacture and extremely inexpensive, and moreover, the wound exudate is effectively absorbed without compressing the wound. It has the effect of promoting the healing of.

Claims (2)

[Claims] 1. A medical water-absorbent polymer laminate, which is a laminate of two kinds of water-absorbent polymers having different water-absorbing capacities, wherein the low water-absorbent polymer layer is a skin adhering layer. 2. A dressing for wound comprising the medical absorbent polymer laminate according to claim 1.