JPH0313902B2 - - Google Patents

Description

[Detailed description of the invention]

This invention provides absorbent wound dressings which have reduced adhesion to the wound and which can act as a bacterial barrier and are suitable for use in burns and other wounds.
Regarding its manufacturing method and uses. Burn injuries and associated donor sites
Wounds, such as those found in the wound sites, pose a serious problem because they exude so much fluid that normal protective materials can become impregnated with this fluid, become fused to the wound, or become infected. One method of covering such wounds is to cover them with a material into which new epithelial cell or fibroblast growth can enter. This type of bandage is disclosed in US Pat. No. 3,526,224,
3648692 and 3949742. However, such guards are very painful to remove and often require surgical excision. Fundamentally different methods requiring fundamentally different types of protection may employ materials designed to have reduced adhesiveness to the wound. This type of protective material is covered by British Patent No. 439085 and French Patent No.
No. 947609, US Pat.
Nephew Limited (Welwyn Garden City,
Herts., UK). In addition, one recent attempt at a non-adhesive protective material has included a microporous, water-repellent fibrous outer layer, a microporous fibrous inner layer, and an absorbent middle layer (also typically applied as a fibrous material). U.S. Patent No. 1, which discloses a protective material having
There is No. 3709221. In order to reduce the adhesion of this material to the wound, the inner layer must be treated with an agent that prevents wetting by body fluids.
Here, it can be seen that it is desirable to provide a protective material that does not require special treatment for the layer facing the wound (wound facing layer). Thus, as will be apparent from the description below, it has been discovered that by avoiding fibrous materials it is possible to produce protective materials that do not require special treatment and have reduced adhesion to wounds. In an attempt to create an absorbent protector, US Pat. No. 3,888,748 discloses a protector made from at least four sheets of material. The scratch-resistant surface layer of this protective material is made of polyethylene obtained by surrounding the filaments of the grid with polyethylene or by assembling either particles or rough threads that may be present as a core material. It is evident from the reticulation or scrim of the coating. It can be seen here that it is desirable to avoid the use of a wound facing layer that allows the intermediate layer to penetrate into the wound surface. Additionally, it would be appreciated that it would be desirable to provide a material that is highly compatible with the wound so that the amount of exudate between the wound surface and the protector can be minimized. U.S. Pat. Nos. 3,709,221 and 3,888,248 disclose materials that are bonded along their edges in response to the need for improved conformance to the contours of the human body. The protective material of the present invention is designed to combine the entire working part while maintaining its flexibility. According to the present invention, there is provided a wound protection material comprising a wound-facing layer, an absorbent intermediate layer, and an outer layer, wherein the wound-facing layer is made of a perforated elastomer film that conforms to the external shape of the human body, and the absorbent intermediate layer is Provided is a low-adhesion wound protection material characterized in that the outer layer is made of a hydrophilic foam that conforms to the external shape of the human body, and the outer layer is made of a moisture permeable continuous film that conforms to the external shape of the human body. The three layers of the protective material of this invention are usually applied adjacently and coextensively. That is, this protective material is usually provided in a laminated state. The perforated elastomeric film of the protective material of this invention, which conforms to the contours of the human body, acts as a low-adhesion wound-facing layer. According to this layer,
Exudate from the wound can pass through the absorbent layer and direct contact of the absorbent layer with the wound surface can be prevented. This elastomeric perforated film is sufficiently biocompatible to ensure that the wound dressing conforms to the contours of the human body and remains in contact with the entire wound surface, ensuring that exudates from the wound are absorbed. It is preferable to have one. Desirably, the elastomeric apertured film should also be sufficiently elastically extensible to accommodate any possible dimensional changes in the absorbent layer, such as expansion due to liquid absorption. . Typically, the elastomeric apertured film is made from a pharmaceutically acceptable water-insoluble polymer.
The preferred polymers used are elastomers. Suitable elastomers include polyurethanes and polybutadienes. Preferred materials for the apertured film are thermoplastic polyurethanes and polybutadienes. Preferred thermoplastic polyurethanes are linear polyurethanes containing polyether or polyester groups. Suitable polyester-based linear polyurethanes are those disclosed in US Pat. No. 2,871,218. Suitable polyether-based linear polyurethanes are those disclosed in US Pat. No. 2,899,411. Suitable thermoplastic polyurethanes include Estanes from BFGoodrich Corp. Preferred casting solution brands are Estan 5714F1, 5702 and 5703.
A preferred extrudate brand is Estan 580201. Suitable polybutadienes are 1,2-polybutadienes. Suitable 1,2-polybutadiene is mainly composed of syndiotactic 1,2-polybutadiene, and has a crystallinity of 25 to 30% and an average molecular weight of 100,000.
It exceeds. Preferred 1,2-polybutadienes are RB810 manufactured by Japan Synthetic Rubber Co., Ltd.
These were known as the RB820 and RB830. The number and size of the holes in the apertured film may be sufficient to allow exudate from the wound to pass through the film and reach the absorbent layer. most suitably such as to prevent contact of the absorbent layer with the wound surface.
The hole size in combination with the film thickness applies to the apertured film. A suitable perforated film has holes with a size of 0.05 to 4 mm, more suitably
0.05-2.5mm or 0.05-2mm hole, preferably 0.1
With ~2.5mm pores. A suitable perforated film is
Has a thickness of 0.01-2.5mm, typically 0.01-0.25
mm, preferably 0.05 to 0.5 mm. The preferred aperture film of this invention is 0.05~
It has 4 to 40 2.5 mm pores per cm. The scratch-resistant surface of perforated film should be between 15 and 80%.
area, more appropriately 25-75% area, most appropriately
It has a pore area of 35-65% area. This perforated film that conforms to the contours of the human body may be in the form of a perforated film or a convenient form such as a net. The perforated elastomeric film used in the preferred embodiment of this invention is an integral net. The term "integral net" refers to a net in which the strands and joints are integrally formed. As the integral net of the wound protection material of the present invention, a simple form can be used depending on the selected arrangement of the strands, joints and holes, and the external shapes and relative sizes of these. . One preferred form of the net is comprised of longitudinal and transverse strands that intersect at right angles, providing a square grid hole pattern. Suitable nets of this type have strands of 2 to 40 cm, preferably 4 to 40 cm, preferably 2 to 24 cm, both in the longitudinal and transverse directions. Other desirable forms of integral nets can be obtained by varying the square grid pattern. If the densities of the longitudinal and transverse strands are not equal, rectangular hole sections are obtained. A staggered arrangement of continuous strands running parallel in one direction and connected strands in the other direction results in a "bricklay" pattern. Other suitable integral polymer nets include angled longitudinal or transverse strands, ie, diagonal strands. According to another preferred embodiment of the integral polymer net, the arrangement of circular or substantially circular (for example hexagonal) strands and the hole portions are staggered. The integral polymer net can be in the form of a mixed pattern of two or more arrangements, if desired. The perforated film used in this invention is preferably 10
It has a weight of ~80 g/m ² , preferably 15-50 g/m ² . The use of elastomeric materials, such as polyurethane or other elastomeric integral nets, provides the desired conformability of the wound dressing of this invention to the contours of the human body. Integral nets of suitable polyurethane or other elastomers can be prepared in 2.5 cm wide strips at 20°C.
Elongation at break of 100-800%, desirably 200-750%, preferably when measured at a stretching rate of 30 cm/min.
It has an elongation at break of 300-700%. Other suitable body-conforming perforated films are thin, flexible elastomeric films with perforations. The moisture-permeable contour-conforming continuous film outer layer of the wound dressing of the present invention serves to control the loss of moisture from the wound area beneath the dressing, and also to reduce the amount of bacteria on the outer surface of the dressing. It also acts as a barrier to prevent bacteria from entering the wound. The appropriate moisture permeability of a continuous film that conforms to the external shape of the human body is 300-5000g, and the preferred moisture permeability is 500-2000g.
g/ ^m2 , 24 hours, 37.5℃, 100-10% relative humidity difference. Such moisture permeability of a continuous film allows the wound under the protectant to heal under humid conditions without macerating the skin surrounding the wound. This outer layer is made from a polymer. Suitable polymers for the outer layer include urethanes and British Patent No.
Copolymers of alkoxyalkyl acrylates or methacrylates as disclosed in No. 1280631 may be mentioned. A preferred outer layer is a biocompatible polyurethane film. Preferred polyurethane films are those made from the linear polyurethanes mentioned above in connection with the scratch-resistant surface layer. The preferred continuous film thickness is 12.5-37.5 μm. A preferred polyurethane having such thickness is Estan 5714F.
Estan 5714F film with a thickness of 25 μm has a moisture permeability of approximately 1800 g/m ² for 24 hours, 37.5° C., and a relative humidity difference of 100 to 10%, and therefore acts to produce a desirable degree of moisture permeability. The outer layer may be a conformable polymer blend film of porous polyurethane and an incompatible polymer. Polyurethane blend films that conform to the appropriate human body contours are disclosed in British Patent Application No. 8122250, Australian Patent Application No. 74000/81, and Canadian Patent Application No. 74000/81.
383751, Danish Patent Application No. 3587/81, Irish Patent Application No. 1793/81, Japanese Patent Application No. 127914/81, New Zealand Patent Application No.
197988, Republic of South Africa Patent Application No. 81/5523
Disclosed in the No. A suitable thickness of the outer layer of polyurethane blend film that conforms to the contours of the human body is 0.0125 to 0.125 mm. Such ilm weighs at least 500g, preferably at least
It has a moisture permeability of 1000g/m ² / 24 hours / 37.5℃ / 100-10% relative humidity difference. A preferred polyurethane blend film consists of a blend of linear polyurethane (60 parts of Estan 580201 available from BF Goodrich) and high impact polystyrene (40 parts of Reflex 6mw available from RHCole Limited). The preferred thickness of this mixture film is 0.084 mm.
It has a moisture permeability of 1660 g/m ² for 24 hours at 37.5°C and a relative humidity difference of 100 to 10%. The outer layer of a moisture-permeable body-contouring continuous film may include a moisture-permeable adhesive layer. In such an adhesive-containing outer layer, the adhesive layer is coated with a moisture-permeable layer that is stretchable so that the non-adhesive surface is on the outer layer of the protective material. At least either the adhesive or the extensible layer is continuous. Preferably, the adhesive layer is continuous. Suitable moisture permeable adhesives for the continuous layer include various acrylic ester copolymers, polyvinylethyl ether, and polyurethane pressure sensitive adhesives. An example of a suitable pressure sensitive adhesive is British Patent No.
It is shown in the specification of No. 1280631. A preferred pressure sensitive adhesive comprises a mixture of high viscosity and low viscosity polyvinylethyl ethers, in particular "Adhesive Composition A" as disclosed in GB 1280631. Other preferred pressure sensitive adhesives are, for example, those consisting of copolymers of acrylic esters and acrylic acid, as disclosed in British Patent Application No. 8106707, in particular 47 parts by weight of butyl acrylate, 47 parts by weight of 2 - a copolymer having an intrinsic viscosity of at least 1.9 dl/g obtained by polymerizing ethylhexyl acrylate and 6 parts by weight of acrylic acid in acetone according to the general procedure described in the above-mentioned British patent application; It will be done. The weight of the continuous adhesive layer is suitably between 15 and 70 g/ ^m2 , preferably between 20 and 40 g/ ^m2 . The extensible moisture permeable layer covering the adhesive layer may be a continuous film that conforms to the contours of the human body as described above. On the other hand, the extensible layer may also be a discontinuous layer. Suitable extensible discontinuous layers include apertured nonwovens that are extensible in at least one direction. A preferred extensible perforated nonwoven fabric is bonded viscose filament.
viscose filaments). A suitable fabric of this type is available as Bemliese (registered trademark) manufactured by Asahi Kasei Corporation. Ben Rees is 18-45
It is available in weights of g/m ² . The preferred fabric is Benleath G204 having a weight of 18.5 g/m ² . The absorbent layer of a hydrophilic foam conforming to the contours of the human body used in the protective material of the present invention is applied to absorb wound exudate, such as exudate from a burn. The hydrophilic foam layer desirably absorbs wound exudate quickly to enhance the low-adhesion properties of the protectant. It has been found that such rapid absorption prevents the accumulation of exudate between the protector and the wound, and that prevention of this accumulation is desirable. Hydrophilic foams that conform to the appropriate human body contours are usually flexible open cell foams. The ability of open cell foams to absorb and retain liquids depends in part on the porosity of the foam and the size of the cells. The appropriate cell size of the hydrophilic open-cell foam of the protective material of this invention is 30 to 700 μm, and 50 to 700 μm.
500 μm is preferred. In the hydrophilic open cell foam of the protective material of the present invention, it is appropriate that the open cell membrane accounts for 20 to 70% of the total cell membrane area, preferably 30 to 60%. Such open cell foam transports and retains liquid and cell debris within the foam. Suitable foams are those of polyurethane, carboxylated butadiene-styrene rubber, polyacrylate, and the like. Such foams may be made from hydrophilic raw materials themselves or may be treated with, for example, surfactants to render them hydrophilic. Due to the fact that coagulation of the exudate is less likely to occur quickly, it is most preferred to use a foam made from a polymer that is itself hydrophilic. By using such a hydrophilic polymer foam in the protective material of the present invention, the wound can be maintained under moist conditions even when exudate is absorbed and detached from the wound surface. Preferred hydrophilic polymer foams are hydrophilic polyurethanes, with those derived from hydrophilic crosslinked polyurethanes being particularly preferred. A preferred foam can be produced by reacting a polyether hydrophilic prepolymer having terminal isocyanate groups with water. Suitable hydrophilic polyurethane foams of this type include those known as Hypol foams. Hypol foam can be made from a hydrophilic prepolymer (Hypol) sold by WRGrance & Co. The thickness of the absorbent layer made of hydrophilic foam is suitably 0.5 to 20 mm, more suitably 0.8 to 15 mm, preferably 1 to 12 mm. The wound protection material of the present invention preferably includes a perforated film that conforms to the contour of the human body, an intermediate layer comprising a hydrophilic polymer foam that conforms to the contour of the human body, and a moisture permeability that conforms to the contour of the human body. and an outer layer made of a continuous film, each of which is bonded to one another and coextensive. The wound protection material of the present invention may be in any convenient form. One preferred form is that of a large shaped pad. The appropriate size for such pads is 10-20cm x 30cm. Another preferred form is that of an elongated strip, which may be in roll form.
Such strips can be used as bandages and can be used to make small protectors. The wound protection material of this invention is preferably sterilized. The protective material of this invention is conveniently supplied in a germ-proof pouch.
Such packaging forms can be manufactured under aseptic conditions or by sterilization after packaging by conventional techniques. One suitable sterilization method is heat sterilization, for example with steam. Other suitable techniques are ethylene oxide sterilization and gamma sterilization. According to another aspect of the invention, an absorbent intermediate layer comprising a stretchable perforated film layer conforming to the contours of the human body, a hydrophilic polymeric foam conforming to the contours of the human body; Provided is a method for manufacturing a low-adhesive wound protection material, which comprises combining a moisture-permeable continuous film with an outer layer made of a moisture-permeable continuous film. Usually, the process of combining the above layers is a lamination process. The prefabricated layers can be bonded together by one or more lamination steps to form a laminate. A suitable method of joining is
Examples include heat sealing and adhesive bonding with a moisture-permeable adhesive layer. In one preferred process, a foam layer is formed in contact with one or both of the other layers. This process is advantageous because it reduces or eliminates many special bonding operations. In another preferred process, an outer layer conforming to the contours of the human body is formed on the foam layer, for example by spraying a polymer solution. In one continuous process, the wound dressing can be manufactured in the form of a continuous strip and then cut into appropriately sized dressings. A hydrophilic polyurethane foam that conforms to the external shape of the human body can be produced by mixing a polyether with terminal isocyanate groups and a functionality of 3 or more with a surfactant and water, and casting the mixture onto a surface. It can be manufactured by Advantageously, the outer layer of the protective material or the anti-scratch layer is applied as this casting surface.
Preferred polyethers having an isocyanate group at the end include Hypol FHP2000, 2001, 3000, sold by WRGrance & Co.
Examples include 3001, 2002 and 2000HD. Hypol is described in a booklet published by WRGrance & Co.
procedures and foam formulation)]. Their manufacture and use is covered by British Patents No. 1429711 and
It is disclosed in the specification of No. 1507232. Suitable surfactants for forming hydrophilic polymeric foams that conform to the contours of the human body include nonionic surfactants. Suitable nonionic surfactants are oxypropylene-oxyethylene block copolymers known as pluronics sold by BASF Wyandotte. Preferred Pluronics include L64, F87,
Mention may be made of P38, P75 and L62. Another suitable nonionic surfactant is polyoxyethylene stearyl ether, known as Brij 72, sold by Honeywell Atlas. A suitable foam is 100 parts by weight Hypol
FHP2000, 2001, 3000, 3001, 2002 or 2000HD
It can be produced by mixing 0.3 to 7 parts by weight of a surfactant (a mixture of two or more types may be used) and 30 to 200 parts by weight of water, and casting this foamed mixture onto a surface. A typical foaming mixture has a cream time of about 20 seconds and a rise time of about 250 seconds.
and has a cure time of approximately 400 seconds. In one continuous step of foam formation, each component is fed to a continuous mixing and dispensing device. Hydrophilic polymeric foam layers that conform to the contours of the appropriate human body can be produced by casting the foam mixture after setting it onto a suitable surface by a casting head device. One suitable mixing and dispensing device is the Prodef
It is known as a biomix (Vario-mix) supplied by Engineering Limited. The foam mixture is made of fishtail dye.
It can be easily supplied to the casting head using a tail die device. In one preferred process of protective material manufacture, where the foam layer is created in contact with the inner layer, it is important that the expanded foam retains its tackiness such that a good bond is obtained; An inner layer should be laminated to this foam. Other inner layers are typically brought into contact with the foam after the foam is molded (cured).
Appropriately it is carried out for 2.5 to 5 minutes, for example 3 to 3.5 minutes. FIG. 1 shows the manufacturing process of the integral polymer net that conforms to the external shape of the human body in the wound protection material of the present invention. FIG. 2 is a plan view showing the casting surface of an embossed pattern sheet for producing an integral polymer net. Figure 3 shows A- in Figure 2.
It is an A-line sectional view. In FIG. 1, a thermoplastic film 1 having an embossed pattern on its surface is fed from a roll 2 to a casting head 3, where a solution 4 is injected into the depressions of this embossed sheet. The wet cast net 5 on the embossed sheet is transferred to an oven 6 where it is dried.
The dried cast net 7 is then separated from the embossed sheet and wound up by rollers 8 while sandwiching a release paper 9 supplied from a roll 10 between the rollers 8. In another preferred step, the dried cast net is separated from the embossed sheet. The coating head (not shown) is equipped with an adjustable doctor blade supported on a flatbed for controlling the amount of casting solution.
A flat bed and side guides are provided to control the width of the casting net. Preferably, the doctor blade has a bottom portion thick enough to span between the divided protrusions of the embossed film to prevent it from getting caught in the recessed portions of the embossed film. The doctor blade and guide plate can be made or coated with a fluorocarbon-based polymer, such as polytetrafluoroethylene, thereby reducing friction against the film. On the other hand, it is also possible to use a fixed or rotating coating head. One suitable application head consists of an adjustable doctor blade supported by a flexible base plate, for example, where the base plate consists of a movable rubber belt over two rotatable rollers, for controlling the amount of casting solution. be. In Fig. 2, a square divided protrusion 1
It is shown that a square grid pattern of recessed areas is provided on the cast sheet embossed by No. 1. FIG. 3, which is a cross-sectional view taken along the line A-A in FIG.
shows. Polyurethane integral nets are produced by casting polyurethane in a flowable state onto a surface that has a pattern of segmented protrusions and interconnecting depressions, and then processing the cast net to form solid integral nets. It can be manufactured by forming a lunet. The flowable polyurethane may be in the form of a solution, suspension, hot melt, powder, etc. which can be dried, coated, melted or otherwise formed into a solid net. The casting surface may be in the form of a roller, an endless flexible belt or a suitable length of sheet material. Preferably, the casting surface is releasable to allow separation of the formed net from this surface. The pattern of segmented protrusions and connecting depressions on the casting surface is selected depending on the desired net structure. One preferred method of manufacturing thermoplastic polyurethane integral nets is to melt embossed a thermoplastic polyurethane solution.
This is a method of casting on a polyolefin sheet and drying it in a heating oven. Suitable casting solutions contain 15-35% by weight thermoplastic polyurethane, preferably 20-30%. A preferred casting solution contains 20-25% by weight of estane 5702 or 5703 in acetone. Other suitable casting solutions contain 25-30% by weight of Estane 5714F in tetrahydrofuran or a mixture of tetrahydrofuran and acetone. Similar techniques can be used to make nets from other elastomers. Melt-embossed polyolefin sheets can be made by the method provided in GB 10559963. A suitable embossed polyolefin sheet has one square pyramid-shaped protrusion with a width of 1 mm and a height of 0.5 mm and a conical side slope of 60 degrees.
There are 8 holes per cm, and the width of the recessed part of the square grid in the vertical and horizontal directions is 0.25 mm at the bottom.
It has a 0.75mm pattern on the top. The preferred embossed polyolefin sheet has a truncated regular pyramidal protrusion of 1.35 mm width at the bottom, 0.7 mm width at the top, and 0.45 mm height with a conical side slope of 70 degrees (45 degrees). It has a pattern with 6 pieces per cm. A preferred embossed polyolefin sheet is
It has a pattern of 2 mm wide at the bottom, 1.425 mm wide at the top, 0.5 mm high, and 4 protrusions per 1 cm in a square arrangement (45 degrees) of regular truncated pyramidal protrusions with a conical angle of 60 degrees on the sides. The thermoplastic polyurethane solution is applied to the shaped polyolefin surface by an application head consisting of a knife over a flat bed, a knife over a roller, or a knife over a soft bed. Can be cast on top. Conforming polyurethane films suitable as the outer layer of the protective material can be formed by solution casting or spraying, hot melt application, or film extrusion by conventional techniques. The preformed polyurethane film can be formed on a release surface, such as a silicone release agent coated paper. Suitable casting solutions are those mentioned above for the production of the abrasion layer of polyurethane integral nets. In another process, a contoured polyurethane film can be formed on a contoured hydrophilic foam layer. In one suitable process, a polyurethane solution is sprayed onto the foam layer. Spraying the polyurethane solution can be carried out in a conventional manner, for example using an air spray gun.
A suitable spray gun is Binks Bullow Limited
The model 630 is available from the company. A suitable method for making an outer layer consisting of an incompatible blend apertured film of polyurethane is disclosed in British Patent Application No. 8124250. The outer adhesive layer can be formed by a simple method such as solution or emulsion coating, hot melt coating, or extrusion. The adhesive layer can also be applied directly onto the protective material substrate, such as a stretchable apertured nonwoven layer. However, it is preferred to transfer the adhesive layer coated onto the release surface and then dried onto the desired substrate by lamination. According to still another aspect of the present invention, there is provided a wound protection material comprising a wound-resistance layer and an absorbent layer, wherein the wound-resistance layer is comprised of a perforated elastomer film that conforms to the external shape of the human body, A low-adhesive wound protection material is provided, wherein the adhesive layer is made of a hydrophilic foam that conforms to the external shape of the human body. Suitable nets and foam layers are those described above. This type of wound protection material lacks the desirable bacterial barrier properties of the three-layered protection material of the present invention, and is somewhat inferior in terms of low adhesion. However, they are still very useful protectants because they are easy to manufacture and can be used where the wound remains sufficiently dry that three layers of protectant are not required. Such wound dressings preferably include an absorbent layer of hydrophilic polymer foam. Therefore, according to another aspect of the present invention, there is provided a wound protection material comprising a wound facing layer and an absorbent layer, wherein the wound facing layer is made of a perforated film that conforms to the external shape of the human body, A low-adhesive wound protection material is provided, the adhesive layer of which is made of a hydrophilic polyurethane foam that conforms to the external shape of the human body. The protective material of the present invention preferably has a scratch-resistant surface layer made of an elastomer integral net that conforms to the contours of the human body. Therefore, according to yet another aspect, there is provided a wound protection material comprising a wound-resistance layer and an absorbent layer, wherein the wound-resistance layer comprises an integral net of an elastomer that conforms to the external shape of the human body, and has an absorbent layer. A low-adhesive wound dressing is provided, the layer of which is comprised of a hydrophilic polymer foam that conforms to the contours of the human body. Typically, two layers of such protective material are applied adjacent and coextensive. That is, this protective material is usually provided in a laminated form. This laminate is
It can be easily formed by the same process as the three-layer protective material of this invention. On the other hand, the wound protectant of the present invention may contain locally effective agents. Antibacterial agents are the most appropriate agents. Antimicrobial agents include silver salts such as silver sulfadiazine, pharmaceutically acceptable iodine sources such as bovidone iodine (also known as polyvinylpyrrolidone iodide salt or PVP/I), chlorhexidine salts of gluconic acid, acetic acid or hydrochloric acid. Agents with a broad antibacterial spectrum are preferred, such as quaternary antibacterial agents such as chlorhexidine salts or benzalkonium chloride. One preferred agent for inclusion in the protective material of this invention is silver sulfadiazine. Yet another preferred agent is chlorhexidine, usually provided as a salt as described above. The drug is present in an amount of 0.2 to 20% by weight, more usually 0.3 to 10%, preferably 0.5 to 5% by weight of the protective material.
Contained (e.g. 1% by weight, 1.2% by weight, 3% by weight)
weight%, etc.). In this invention the drug is present in the foam layer. A surprising feature of this invention is that antimicrobial agents can be incorporated into the hydrophilic polyurethane foams so that these serve to help keep the wound facing the protector free of infection. Agents such as silver sulfadiazine, chlorhexidine hydrochloride, etc. are added to the protofoam prior to polymerization.
foam), which is particularly surprising. This is because, although one would expect significant changes in the properties of the foam to occur in the presence of compounds containing basic nitrogen atoms, it has now been found that these do not occur. The agent may be introduced prior to foaming or may be introduced into the prefabricated foam itself. If the agent is introduced prior to foaming, the agent must not have any reactive moieties that would react with the components of the mixture being foamed (e.g., it must not contain free amino groups that could react with the isocyanate groups present). or else the drug must be of low solubility to limit its potential reactivity.
Thus, for example, agents such as silver sulfadiazine or chlorhexidine hydrochloride can be foamed by dispersing them in the desired amount in a prepolymer mixture, such as by dispersing the agent in an aqueous solution of a surfactant and then mixing in the isocyanate-containing raw material. It can be easily introduced into the body. The most suitable insoluble drug is one that is finely ground, most preferably one that is ultrafinely ground. It has been found that more soluble salts such as chlorhexidine gluconate cannot be introduced in this way. This is because a reaction with the prepolymer component occurs and the resulting foam is harder and antibacterially ineffective. It has been fortunately discovered that soluble drugs can be incorporated by impregnating the foam with a solution of the drug after the foam has been manufactured. It has therefore been found that, for example, a 2 x 2 cm protective material of the invention, immersed in 50 ml of a 5 W/V % solution of chlorhexidine gluconate for 48 hours and then dried, has antibacterial properties. In different embodiments of the invention, the wound dressing can be in the form of a compression bandage. The most suitable compression bandages of this invention have two or more elastic layers. In another embodiment of the invention, a low adhesion layer comprising a wound-facing layer of an elastomeric perforated film, an intermediate layer of hydrophilic foam that conforms to the contours of the human body, and an outer layer of a stretchable, moisture-permeable continuous film. A pressure bandage is provided. The most suitable elastomeric perforated film is the net described above. In the preferred compression bandage of this invention, the integral net wound facing layer, the foam middle layer and the film outer layer are made from the polyurethane described above. The low adhesive compression bandage of this invention can be used to cover skin grafts. In this application, the bandage acts to absorb exudate from around the skin graft and to compress the area to prevent scarring due to enlargement of the skin graft. The low-adhesive compression bandage of this invention can also be used to treat ulcers, such as leg ulcers. The bandages of this invention are typically 1 to 4 m long and 5 to 4 m wide.
Supplied as a 20cm roll. After the wound protection material of this invention is manufactured, it can be washed with water to remove excess surfactant and dried. It has surprisingly been found that the appearance of the protective material is significantly influenced by the method of drying. Some air-dried protectants were observed to be curly. In some cases, the outer layer is wrinkled, giving the film a grained surface or skin texture. It has been found that protectants autoclaved using a vacuum drying system tend to remain flat.
The outer film has a wrinkled surface. It has been found that protectants that are incompletely dried, ie, have a low amount of residual water absorbed into the polymer of the foam rather than in the void air of the foam, are planar. This unexpected effect is also useful. This is because the protector will retain its planar shape if it is protected from water loss, such as when the protector is packaged in a watertight bag. In such incompletely dried protective materials,
No wrinkles occur in the film or net. It has been found that a protective material containing residual water in such a state has a pleasantly cool feel. As indicated above, the protectant of the present invention may be adapted to release an antimicrobially effective amount of an antimicrobial agent into a wound covered with the protectant. Therefore,
According to another aspect, the present invention provides a method for preventing infection of a wound or aiding in maintaining a preventive state of the wound, comprising contacting the wound with a protective material of the present invention adapted to release an antimicrobial agent. A method of treatment is provided. From this point of view, it is most appropriate to use it for preventing burn infection or maintaining a preventive state.
Suitable antimicrobial agents present are silver salts such as silver sulfadiazine, chlorhexidine salts such as chlorhexidine hydrochloride, or mixtures thereof. The absence of fibrous materials in the dressing increases the non-adhesive properties of the wound dressing of the present invention. This invention will be explained in more detail below using reference examples and examples. Reference example Manufacture of integral polyurethane net A tetrahydrofuran solution containing 30% by weight of Estan 5714F1 was applied using a blade over flat bed spreading technique.
It was cast into a 15 cm wide depression in a melt-embossed high-density polyethylene sheet. The bottom of this sheet is 1mm
The sides have a conical angle of 60° in width and height.
It had a melt-embossed pattern with 8 0.5 mm square pyramid-shaped protrusions per 1 cm. The wet cast net on the embossed film was dried in a hot air circulating oven for 2 minutes at a temperature of 90-100°C. The dried cast net was separated from the embossed film and rolled around a roller with double-sided silicone release paper in between. The resulting cast body of the elastomer polyurethane net had the following physical properties. Weight 40g/ ^m2Thickness 100~125μm Hole size 0.3~0.4mm Tensile strength (g/2.5cm width) Longitudinal 800±51 Lateral 664±57 Elongation at break (%) Longitudinal 389± 24 Lateral direction 374±24 Polyurethane diamond-shaped net body (6 holes/
Production of a cast sheet with a base width of 1.35 mm, a conical angle of 70° on the side surfaces, and a conical trapezoidal projection with a height of 0.45 mm in a diagonal arrangement (45°) with 6 per 1 cm.
The net was cast in the same manner as the shaped net described above, except for the unique melt-embossed pattern. Example 1 Production of low-adhesion wound protection material Brij 72 (2% aqueous emulsion) was placed in a beaker.
22.5g) and Pluronik F87 (0.5ml of 10% aqueous solution)
Mix this mixture Hypol
FHP3001 (15 g) was added and thoroughly mixed with a metal spatula until the Hypol was evenly dispersed (20 seconds). The foaming mixture was cast into a 25 μm thick estane.
5714Fl film was poured into a 15 cm wide brass manual application box with a 1.8 mm gap. The foam layer was then manually poured from the application box onto the film surface to form a foam layer on the film. Next, the integral polyurethane net cast product obtained in the reference example was applied until the smoothest surface of the net was 3 to 3 minutes after the start of coating.
Position and laminate on top of cured foam for 3.25 minutes. The foam layer was well bonded to the net without large craters. Alternatively, a wound dressing can be made in a similar manner by coating the foam on an integral polyurethane net (preferably on an embossed film carrier) and laminating the film to the cured foam. Example 2 A wound protection material consisting of a hydrophilic polyurethane film absorbent layer bonded with a polyurethane integral net was prepared by forming a foam layer on the polyurethane integral net in the same manner as the wound protection material of Example 1. Manufactured by. Samples of the wound protection materials of Examples 1 and 2 and hydrophilic polyurethane foam for comparison were washed with distilled water and
It was dried at ℃ for 12 hours and tested for wound adhesion. Example 3 Brij 72 (30 g as a 2.5% aqueous solution) was added to Hypol FHP3001 (20 g) in a beaker, stirred and mixed with a metal spatula, and then stirred with a stirrer until Hypol was uniformly dispersed (about 20 seconds). . The foamed mixture was cast by a flat blade coating head with a 0.1 mm gap onto a 6 hole/cm diamond pattern net as described above on an embossed film carrier. A 25μ thick film (Estan 5714Fl) on silicone release paper was laminated to the foam surface using light finger pressure while the foam layer was not yet cured (approximately 3 minutes after application). After 15 minutes, the embossed film and silicone-coated release paper were removed from the net and the film surface of the strip, and the strip was then cut into 30 cm x 15 cm wound dressings. This protective material was washed twice with 1 portion of distilled water and air-dried. Example 4 A wound protection material was produced in the same manner as in Example 3 except that the gap was changed from 0.1 mm to 0.5 mm. Example 5 A wound protection material was manufactured in the same manner as in Example 3 except that the gap of 0.1 mm was changed to 1.0 mm. Example 6 The wound dressing of Example 4 was autoclaved at 116°C for 30 minutes followed by a vacuum drying cycle. Example 7 The wound protection material of Example 5 was autoclaved in the same manner as Example 6. Example 8 The protective material of Example 5 was washed and dried by partially applying an absorbent towel. The following Examples 9 to 13 relate to the production of medical wound protection materials according to the present invention. Example 9 A wound dressing was prepared in the same manner as in Example 4, except that silver sulfadiazine powder (0.2 g) was mixed into the Brij 72 emulsion in a high-speed shear mixer prior to the addition of Hypol FHP3001. Example 10 A wound protection material was produced in the same manner as in Example 9, except that 1 g of chlorhexidine hydrochloride powder was used instead of sulfadiazine silver powder (0.2 g). Example 11 The wound protection material produced in Example 4 was treated with a chlorhexidine gluconate aqueous solution (5w/v% solution).
Soaked in a tray for 10 minutes and air-dried. Example 12 A wound protection material was produced in the same manner as in Example 11, using an aqueous solution of chlorhexidine acetate (5% by weight/volume) instead of an aqueous solution of chlorhexidine gluconate. Example 13 Using povidone iodine aqueous solution (10w/v%) instead of chlorhexidine gluconate aqueous solution,
A wound protection material was produced in the same manner as in Example 11. Example 14 A wound dressing consisting of a hydrophilic polyurethane absorbent layer bonded with a polyurethane integral net was prepared in the same manner as the wound dressing of Example 8 in which a foam layer was formed on the polyurethane integral net. Manufactured. Example 15 Example using 20g of Bridge 72 instead of 30g
A wound protection material was manufactured in the same manner as in Example 14. Example 16 A wound protection material was produced in the same manner as in Example 14 except that 40 g of Brij 72 was used instead of 30 g. Example 17 Pluronic L64 in surfactant emulsion
(0.5 ml of 10% aqueous solution) was added to produce a wound protection material in the same manner as in Example 14. Example 18 A wound protection material was produced in the same manner as in Example 17 using Pluronic F68 instead of Pluronic L64. Example 19 A wound protection material was produced in the same manner as in Example 17 using Pluronic F108 instead of Pluronic L64. Example 20 Wound treatment in the same manner as in Example 1 using Brij 72 (30 g of 2.5% aqueous emulsion) instead of Brij 72 (22.5 g of 2% aqueous emulsion) and Pluronic F87 (10% aqueous solution) mixture. Protective materials were manufactured. Example 21 Bridge 72 and Pluronik P75 (10% aqueous solution at 0.5
A wound protection material was produced in the same manner as in Example 20 using a mixture of ml). Example 22 Cast polybutadiene (reference RB830) net (8 holes in 1 cm) instead of polyurethane net
A wound protection material was manufactured using the same method as in Example 1. Example 23 Manufacture of a compression bandage A bandage strip was prepared in the same manner as the wound dressing strip of Example 3 using a blade set with a 0.5 mm gap. The strips were washed with distilled water and air dried. A 1 cm wide bandage had the following stress-strain relationship. Table 1 Stress (%) 25 50 100 Strain (g/cm) 360 610 800 As shown in the compressive properties of bandages in Table 2 below, by stretching a single layer bandage with different forces, one end of the radius (R) The pressure (P) exerted on the bandage was calculated from the stress-strain relationship using the equation P=F/R, where F is the force (in g/cm) that will distract the bandage due to the applied force.

[Table] Antibacterial properties of medical wound protection materials Diameter 15 of each medical wound protection material of Examples 9 to 13
A sample of mm was moistened and left on an agar medium inoculated with Staphylococcus aureus or Bacillus subtilis at the optimum growth temperature for 24 hours. The inhibition zone created by leakage of the drug from the protective material was measured and shown in Table 3 below.

[Table] Successive tests of the same samples were carried out to determine the results.
Example 24 Integral diamond pattern net (4
Production of holes/cm) A solution containing Estane 5714F (20% by weight) in a mixture of tetrahydrofuran/acetone (60/40 weight ratio) was cast into a 15cm-wide depression in a melt-embossed high-density polyethylene sheet using a flexible platform casting blade. It spread to the department. This sheet is 2mm wide at the bottom and 1.42mm wide at the tip.
Conical pyramidal trapezoidal protrusions with a width and height of 0.5mm and a conical angle of 60° on the sides are arranged in a 1cm diagonal pattern.
Each sample had four melt-embossed patterns. Wet cast (cast) net in embossed film,
It was dried by passing it through a hot air oven at 80°C for 2 minutes. This net weighed 33 grams ^per square meter and had 4 holes per cm of approximately 1.4 mm size. Manufacture of absorbent layers Two-component mixing and dispensing equipment (Prodef
Hypol FHP2002 and Bridge 72 (2% aqueous solution) were mixed in a ratio of 1:2.25 to form a foamed mixture using Variomics (supplied by Engineering Limited). The foamed mixture was fed to the casting head using a 15 cm fish tail die type outlet tube and cast onto a polyurethane net (a net on an embossed film) using a roller casting knife with a 1 mm gap. It was applied to. The applied foam was dried through a circulating air oven at 50° C. for 5 minutes. Production of outer layer of biocompatible film Tetrahydrofuran/acetone mixture (60/40
Weight ratio) to polyurethane (Estan 5714F)
% by weight solution was hand sprayed onto the foam surface of the foam/net composite layer using an air spray gun (Model 630 available from Brinks Bullow Limited). This was dried through a circulating air oven heated to a temperature of 70°C. The polyurethane coating is continuous and weighs approximately 30g ^per square meter.
The weight was . The embossed film was then removed from the three-layer composite strip and the strip was cut into appropriate lengths of protection for use in adhesion testing. Example 25 In the same manner as in Example 24, a strip consisting of a foam-net composite layer was prepared on an embossed film. Stretchable perforated nonwoven fabric (Benleith GS204)
moisture-permeable acrylate copolymer adhesive (30
g/m ² ) and laminated to the foam layer of the composite strip to form a contoured outer layer of the human body. The above adhesive was prepared according to the method described in British Application No. 8106707, containing 47 parts by weight of n-butyl acrylate,
A copolymer having an intrinsic viscosity of 1.9 was obtained by polymerizing 47 parts by weight of 2-ethylhexyl acrylate and 6 parts by weight of acrylic acid in acetone. The embossed film was then removed from the composite strip and the strip was cut into protectors of a size suitable for this invention. Example 26 Preparation of a two-layer protective material In the same manner as in Example 23, a foam-net composite strip was prepared on an embossed film. The embossed film was removed from the foam-net composite strip and cut into appropriate protector sizes for adhesion testing. This protective material is 2.3mm thick and weighs 340g per ^1m2 .
The weight was . Examples 27-34 Two-layer wound protection consisting of a hydrophilic polyurethane absorbent layer bonded with integral polyurethane nets according to the methods of Examples 3-5 and 9-13, except without the step of laminating the film. manufactured the material. Example 35 A two-layer net-foam protective material was produced in the same manner as in Example 2, using cast polybutadiene (RB830) net (8 holes/cm) instead of the polyurethane net. Example 36 A wound protection material was produced in the same manner as in Example 24, using cast polybutadiene (RB830) net (6 holes/cm) instead of the polyurethane net. Example 37 A wound protection material was produced in the same manner as in Example 26, using cast polybutadiene (RB830) net (6 holes/cm) instead of the polyurethane net. Adhesion Test Nine guinea pigs were grouped into one group, and hair was removed from the thorax to abdomen. Localized deep burns with a diameter of 2.5 cm were created in two places on the flanks by contacting them with hot water at 65°C for 15 seconds. The skin was dried and the burnt area was scraped with a surgical knife to remove the epidermis. Histological sections preliminarily showed that this technique separates the skin between the epidermis and dermis. The protective material was attached to the wound with a margin of about 1 cm around the wound. A claved bandage was wrapped around the animal and secured with an elastic adhesive bandage. The protective material was left in place for 24 hours. The animals were then sacrificed with an intracardial injection of bentobarbital, and a sufficiently thick strip of skin was removed with a rough margin around the animal's wound. Biopsies were then taken using an Instron tensile testing machine by peeling the protector off the skin at a speed of 5 inches per minute.
Average value, maximum value and total tensile force required for removal (g)
was recorded. As a result, when removing the protective materials of Examples 4, 24, and 26, Mellolin (non-adhesive protective material product)
In the case of Examples 1 and 2, only about 1/8 and about 1/3 energy were required compared to merolin, respectively. [Note] Mellolin is an absorbent wound protection material consisting of a polyester film (wound surface layer) that conforms to the external shape of the human body, to which is adhered an absorbent pad made of a mixture of cotton and rayon fibers (TJ
Manufactured by Smith and Nephew Limited).

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of the manufacturing process of an integral polymer net adapted to the external shape of the human body used in the wound protection material of the present invention. FIG. 2 is a plan view of essential parts showing an example of the casting surface of an embossed pattern sheet for producing an integral polymer net, and FIG. 3 is a sectional view taken along the line A--A in FIG. 2. 1... Thermoplastic film having an embossed pattern, 2
... Roll, 3 ... Casting head, 4 ... Casting solution,
5...Liquid casting net, 6...Oven, 7...
Casting net, 8...Roller, 9...Release paper, 1
0...Roll, 11...Protrusion, 12...Recessed portion.

Claims (1)

[Claims] 1. A wound protection material comprising a wound protection layer, an absorbent intermediate layer, and an outer layer, the protection material comprising a wound protection layer made of a perforated elastomer film that conforms to the external shape of the human body; A low-adhesion wound protection material comprising a laminate of an absorbent middle layer made of a hydrophilic foam that conforms to the external shape of the human body and an outer layer made of a moisture-permeable continuous film that conforms to the external shape of the human body. 2. The protective material according to claim 1, wherein the perforated elastomer film that conforms to the external shape of the human body is made of integral net. 3 The perforated elastomer film is
The protective material according to claim 1 or 2, having 4 to 40 holes of 0.05 to 2.5 mm per cm. 4. The protective material according to any one of claims 1 to 3, wherein the perforated elastomer film that conforms to the external shape of the human body is made of polyurethane. 5 The outer layer, a moisture permeable continuous film that conforms to the external shape of the human body, is 500 to 2000 g/ ^m2 , 24 hours, 37.5℃, 100
The protective material according to claim 1 or 2, which has a moisture permeability of ~10% relative humidity difference. 6. Claims 1 to 6, wherein the moisture permeable continuous film that conforms to the external shape of the human body is made of polyurethane.
The protective material according to any of Item 5. 7. The protective material according to any one of claims 1 to 6, wherein the moisture permeable continuous film of the outer layer that conforms to the external shape of the human body includes a moisture permeable adhesive layer. 8. The protective material according to any one of claims 1 to 7, wherein the moisture permeable continuous film that conforms to the external shape of the human body has the characteristics of an elastomer. 9. The protective material according to any one of claims 1 to 8, wherein the hydrophilic foam is a hydrophilic polymer foam. 10. The protective material according to claim 9, wherein the hydrophilic polymer is hydrophilic polyurethane. 11 The hydrophilic foam has a bubble size of 50~
The protective material according to any one of claims 1 to 10, which is made of a 500 μm open cell foam. 12 Hydrophilic foam accounts for 30-60% of the total cell membrane area
The protective material according to any one of claims 1 to 11, which is made of an open-cell foam that is an open-cell membrane. 13. The protective material according to any one of claims 1 to 12, which contains a locally effective drug. 14. The protective material according to any one of claims 1 to 13, which is placed in a bacteria-impermeable bag. 15 A wound protection material comprising a wound protection layer and an absorbent layer, the protection material comprising a wound protection layer made of a perforated elastomer film that conforms to the external shape of the human body;
A low-adhesion wound protection material comprising a laminate with an absorbent layer made of a hydrophilic foam that conforms to the external shape of the human body. 16. The protective material according to claim 15, wherein the perforated elastomer film that conforms to the external shape of the human body is made of integral net. 17 The size of the perforated elastomer film
The protective material according to claim 15 or 16, having 4 to 40 holes of 0.05 to 2.5 mm per cm. 18. The protective material according to any one of claims 15 to 17, wherein the perforated elastomer film that conforms to the external shape of the human body is made of polyurethane. 19. The protective material according to any one of claims 15 to 18, wherein the hydrophilic foam is a hydrophilic polymer foam. 20. The protective material according to claim 19, wherein the hydrophilic polymer is hydrophilic polyurethane. 21 Hydrophilic foam has a bubble size of 50~
The protective material according to any one of claims 15 to 20, which is made of a 500 μm open cell foam. 22 Hydrophilic foam accounts for 30-60% of the total cell membrane area
22. The protective material according to any one of claims 15 to 21, which is made of an open-cell foam that is an open-cell membrane. 23. The protective material according to any one of claims 15 to 22, which contains a locally effective drug. 24. The protective material according to any one of claims 15 to 23, which is placed in a bacteria-impermeable bag.