KR200185721Y1 - Foam type dressing with microporous skin layer - Google Patents

Abstract

The present invention relates to a foam dressing material having a microporous skin structure used as a wound coating material. It is an object of the present invention to provide a foam dressing material having high moisture permeability and non-window adhesion properties with a simple processing process by improving the problems of low moisture permeability, wound surface adhesion, and complicated processing processes, which are disadvantages of existing foam dressing materials.

The foam dressing material of the present invention is an inner foam layer having a double-sided skin layer having pores of 3 to 60 µm in diameter and an open cell having a diameter of 50 to 500 µm between the two skin layers. It has a water absorption of 500-1,500 wt% and a water vapor transmission rate of 1,500-9,000 g / m 2/24 hrs. The foam dressing material of the present invention is a general-purpose closed dressing material having excellent effluent absorption and water releasing power, preventing window adhesion, and having excellent wound healing effect in a wet environment.

Description

Foam Type Dressing with Microporous Skin Layer

The present invention relates to a closed foam dressing material used as a wound dressing. Specifically, the structure is a double-sided skin layer (1) having pores (2) having micropores with a diameter of 3 to 60 µm and an inner foam layer (3) having an open cell (4) having a diameter of 50 to 500 µm between the two skin layers. It has a water absorption of 500-1,500 wt% and a water vapor transmission rate of 1,500-9,000 g / m 2 / 24hrs.

In general, skin is one of the organs that protects the human body from external attack, controls vital body moisture, controls body temperature, prevents bacterial invasion, and protects and regulates skin when defects occur due to burns or other trauma. Loss of function leads to dysfunction, various side effects due to water loss and bacterial infections from outside, making it difficult to treat the affected area or additional side effects such as secondary dysfunction or damage. Will be given. Therefore, in order to quickly heal wounds and minimize secondary side effects, it is necessary to treat wounds with appropriate dressings.

Major factors involved in wound healing include wet environment, infection, foreign body and necrotic tissue, temperature, oxygen concentration and pH. The ideal dressing material requirement is to maintain adequate moisture at the contact surface with the wound, high absorption of exudates, non-stick adhesion and easy removal of the dressing material, good gas and vapor transfer to the outside, insulation from the outside, and invasion of bacteria. Defense against, non-toxic to human body, excellent mechanical properties, economics and the like.

Ordinary gauze dressings are easy to absorb wound secretions, but they do not have the ability to protect against infections such as bacteria from the outside and keep the wound dry so that treatment is delayed. But there are problems involving neoplastic damage and pain. In addition, there is a disadvantage that the dressing should be changed several times a day because a large amount of exudate occurs in the early stage of healing. Currently, various closed dressing materials have been developed and used to improve the problems of the gauze-type dressing materials. However, due to the high price and lack of controllability of hygroscopicity and moisture permeability, they are not widely applied to various wounds and are mainly applied to specific wounds. Types of dressing materials currently used mainly include film, hydrocolloid, hydrogel, nonwoven, and foam. In particular, the foam form is expected as a dressing material that can be easily applied to a wide range of versatility and various wounds because of its hygroscopicity and easy control.

Foam dressings currently available include Allevyn from Smith & Nephew (USA) and PolyMem from Ferris Mfg. (USA). Allevyn has a structure in which a film is laminated on both sides of a plate-shaped polyurethane foam, and the film contacting the wound surface is mechanically drilled with fine holes to allow the exudates to be well absorbed. However, when applied to wounds in which a large amount of exudate is generated, there is a problem that the permeability of the outer film that is not perforated is insufficient, so that it is not suitable for long-term adhesion, and the growth tissue penetrates into the holes present in the wound side film. There is a problem such as attached.

PolyMem has a structure in which a film is laminated on one side of a plate-shaped polyurethane foam, and is applied so that the foam directly contacts the wound surface. Therefore, as in the case of Allevyn, the difficulty of long-term adhesion due to insufficient moisture permeability, window attachment as the regenerated tissue grows into the open cell of the foam, and thus cause tissue damage and pain during exchange There is a problem.

In addition, all of the above products have a disadvantage in that the manufacturing process such as film production, foam production, film adhesion, hole formation, and the like is complicated.

An object of the present invention is to improve the disadvantages of the conventional foam dressing material and to provide a foam dressing material that can be applied to various wounds of the structure having a high absorption, high moisture permeability, non-adhesive wound surface, a simple manufacturing process.

1 is a schematic cross-sectional view of a foam dressing material

2 is a scanning electron microscope photograph of the surface of the foam dressing material. FIG. 3 is a scanning electron microscope photograph of the internal cross section of the foam dressing material.

<Description of the code | symbol about the principal part of drawing>

1. epidermal layer 2. pores, micropores of the epidermal layer

3. Foam layer of open cell structure 4. Open cell

Hereinafter, the present invention will be described in detail.

The foam dressing material of the microporous skin structure of the present invention has an inner foam layer having a double-sided skin layer 1 having a plurality of pores 2 having a diameter of 3 to 60 μm and an open cell 4 having a diameter of 50 to 500 μm between the two skin layers ( 3) consists of a plate-like foam consisting of. The thickness is in the range of 1 to 7 mm and the width and shape can be produced in various ways depending on the application. The skin layer 1 has a large number of pores 2 having a diameter of 3 to 60 µm, and the pore area occupies 5 to 50% of the skin layer area. From this structural characteristic, it has a function of preventing the invasion of foreign substances such as water and bacteria from the outside, exhibits high moisture permeability, and has non-adhesiveness to the wound surface. The inner layer 3 is a foam having an open cell 4 having a diameter of 50 to 500 µm, an open cell ratio of 80% or more, and a specific gravity of 0.15 to 0.4. In addition, mechanical properties and absorbency have properties similar to those of conventional foam dressing materials.

The foam dressing material of the microporous skin structure of the present invention can be produced using polyurethane, polyethylene, silicone resin, natural and synthetic rubber. Polyurethane is the most preferred material as a polyurethane prepolymer obtained by reacting at least one polyetherpolyol with diisocyanate in an amount of 40 to 80% by weight, 15 to 45% by weight of blowing agent, 5 to 40% by weight of crosslinking agent and 0.5 to 15% by weight of additive. The mixture is stirred by adding%, and then poured into a mold to prepare a foam.

As isocyanate to be used, isophorone diisocyanate, 2, 4- toluene diisocyanate and its isomer, diphenylmethane diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, trimethyl hexamethylene diisocyanate, 2, -2 bis- 4'-propane isocyanate, 6-isopropyl-1,3-phenyldiisocyanate, bis (2-isocyanate ethyl) -fumarate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 1, 6-hexanediisocyanate, 4,4'-biphenylene diisocyanate, 3,3'-dimethylphenylene diisocyanate, p-phenylene diisocyanate, m-phenylenedi isocyanate, 1,5-naphthalene diisocyanate, 1,4- Xylene diisocyanate, 1, 3- xylene diisocyanate, etc. are used. As polyether polyols, a single or mixed polypropylene glycol having two or more hydroxyl groups in a molecule having a molecular weight of 1,000 to 4,000 and an ethylene oxide / propylene oxide random copolymer having a molecular weight of 3,000 to 6,000 having three or more hydroxyl groups in a molecule Use it.

The blowing agent uses chlorofluorocarbon (CFC-141b), methylene chloride, distilled water.

The crosslinking agent is 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentylglycol, propylene glycol, ethylene glycol, having a molecular weight of at least two hydroxyl groups in the molecule 2000 polyethylene glycol, trimethylolpropane, etc. are used.

As an additive, a hydrophilicity imparting agent, a mold release agent, an antifoamer, an antibacterial agent, etc. can be used.

Hereinafter, the present invention will be described by synthesis examples, examples, and comparative examples, but these are merely provided to explain the present invention in detail, and the technical scope of the present invention is not limited thereto.

Synthesis Example 1

Preparation of polyurethane polymers having isocyanate end groups was carried out using a 3 liter round bottom flask equipped with a stirrer, and 335 g of diphenylmethane diisocyanate was added and heated to 60 ° C. 1665 g of TR-705 (Polyol Korea Co., Ltd.) having a copolymer and 75% ethylene oxide content was added in small amounts to react for 7 hours until the theoretical NCO% was reached. Samples were taken in the middle of the reaction to determine NCO% and NCO% was determined by titrimetry using n-butylamine standard solution.

Synthesis Example 2

454 g of diphenylmethane diisocyanate was added to a 3 liter round bottom flask equipped with a stirrer, and the temperature was raised to 60 ° C., followed by three hydroxyl groups, an ethylene oxide / propylene oxide random copolymer, and a ethylene oxide content of 75% TR- 1705 g of 705 g was added in small portions to react for 7 hours until the theoretical NCO% was reached. Samples were taken in the middle of the reaction to measure NCO%, and NCO% was determined by titrimetry using n-butylamine standard solution.

Synthesis Example 3

347 g of diphenylmethane diisocyanate was added to a 3 liter round bottom flask equipped with a stirrer, and the temperature was raised to 60 ° C., followed by three hydroxyl groups. It was prepared by adding 1315 g of TR-705 having a ethylene oxide content of 75% in small amounts and reacting for 7 hours until the theoretical NCO% was reached. Samples were taken during the reaction to measure NCO%, and NCO% was determined by titrimetry using n-butylamine standard solution.

Example 1

The foam dressing material was 24% by weight of distilled water, 13% by weight of glycerin, 2.5% by weight of F-127 (BASF) as an additive, and 0.5% by weight of STARTEX 201 Yellow (Songwon Color), based on 60% by weight of the polyurethane prepolymer prepared in Synthesis Example 1. After adding 5% by stirring at 3,000 to 5,000rpm and injected into a mold of a predetermined shape to prepare a foam. At this time, the temperature of the mold is set to 30 to 50 ° C., and the mold is opened and closed after 10 to 15 minutes after injection.

The foam dressing material was 5mm thick, and the physical properties were measured by the following method.

① Mechanical Properties (tensile strength, elongation, modulus)

It measured by the tensile tester (Universal Test Machine, USA, Instron) based on JIS-K-6401.

② Absorbance%

The foam dressing material was taken in a size of 3Cm × 3Cm, dried in an oven at 70 ° C for 24 hours, the initial weight (A) was measured, impregnated and stored in distilled water at 25 ° C for 48 hours, and then removed. After the weight (B) is measured and calculated using the following equation.

Absorbance% = (B-A) / A × 100

③ moisture permeability

It is measured according to the KS M 6886 test method using a thermo-hygrostat. At this time, the temperature is 40 ℃ and the relative humidity is 90% and the moisture permeability is calculated according to the following equation.

P = A / S

A = ((a ₁ -a ₀ ) + (a ₂ -a ₁ ) + (a ₃ -a ₂ )) / 3

Where P: breathability (g / m ² / 24hrs)

A: average increase over 1 hour (g)

S: moisture permeation area of the test piece (m ² )

a ₀ : Weight measured after 1 hour

a ₁ , a ₂ , a ₃ : Weight measured after 2 hours, 3 hours and 4 hours

④ Cell size

Scanning electron microscope is used to measure the cell size of the surface and cross section of the foam dressing material.

⑤ Toxicity test on cells

Toxicology evaluation of the foam dressing material cells was used the method of ISO-10993-5. Secondary cultures were performed using 3T3 cells, mouse fibroblasts provided by the National Institute of Hygiene. 3T3 cells were seeded at 2 × 10 ⁴ / cm with Roswell Park Memorial Institute-1640 (RPI-1640) containing 10% Fetal Calf Serum (FCS) in a 12-well plastic culture dish, and 37 ° C., 5% CO Incubated under _{2 for} 4 days. The hydrophilic polyurethane foam dressing material was brought into direct contact with each other and left for 1 to 3 days, and then harvested using trypsin / Ethylene Diamine Tetraacetic Acid (EDTA) solution and stained with 0.4% trypan blue solution. The number was measured with a hemasitometer.

⑥ Measurement of wound healing effect

In order to observe the wound healing effect of the foam dressing material, an average age of 5 weeks and a weight of 25-30 g were used. After the rat was anesthetized with ether, two skin defects with a diameter of 6 to 30 mm were made on the back, and one was dressing and the other was not dressing as a control. At 3, 6, and 9 days after dressing, changes in the size of skin defects and detachment of tissue cells were observed.

Example 2

The foam dressing material was added to 53% by weight of the polyurethane prepolymer prepared in Synthesis Example 1 by adding 24% by weight of distilled water, 19% by weight of glycerin, 2.5% by weight of F-127, 1.0% by weight of hyaluronic acid and 0.5% by weight of STARTEX 201 Yellow. After stirring for 5 seconds at ˜5,000 rpm, it is injected into a mold of a predetermined shape to prepare a foam. At this time, the temperature of the mold was 30 to 50 ° C., and the mold was opened and closed after 10 to 15 minutes after the injection. Physical properties were measured by the method illustrated in Example 1.

Example 3

Foam weighing material is 26% by weight of distilled water, 13.5% by weight of glycerin, 13.5% by weight of F-127, 0.1% by weight of Silver Sulfadiazine, STARTEX 201 in 57% by weight of the polyurethane prepolymer prepared in Synthesis Example 1 0.5% by weight of yellow is added and stirred at 3,000 to 5,000 rpm for 5 seconds, and then injected into a mold of a predetermined shape to prepare a foam. At this time, the temperature of the mold is set to 30 to 50 ° C., and the mold is opened and closed after 10 to 15 minutes after injection. Physical properties were measured by the method illustrated in Example 1.

Example 4

The foam dressing material was added to 60% by weight of the polyurethane prepolymer prepared in Synthesis Example 2 by adding 24% by weight of distilled water, 13% by weight of glycerin, 2.0% by weight of F-127, 0.5% by weight of hyaluronic acid, and 0.5% by weight of STARTEX 201 Yellow. After stirring for 5 seconds at ˜5,000 rpm and injected into a mold of a predetermined shape to prepare a foam. At this time, the temperature of the mold is set to 30 to 50 ° C., and the mold is opened and closed after 10 to 15 minutes after injection. Physical properties were measured by the method illustrated in Example 1.

Example 5

The foam dressing material was 3,000 by mixing 60 weight 5 of the polyurethane prepolymer prepared in Synthesis Example 3, 23 weight% of distilled water, 13 weight% of glycerin, 3.0 weight% of F-127, 0.5 weight% of hyaluronic acid, and 0.5 weight% of STARTEX 201 Yellow. After stirring for 5 seconds at ˜5,000 rpm, it is injected into a mold of a predetermined shape to prepare a foam. At this time, the temperature of the mold is set to 30 to 50 ° C., and the mold is opened and closed after 10 to 15 minutes after injection. Physical properties were measured by the method exemplified in Example 1 and the experimental results are shown in Table 1 below.

Comparative Example 1

Commercially available S company (Allevyn) was applied and the manufacturing method is as follows. Into a 3 liter round bottom flask with a stirrer, 347 g of 2,4-toluene diisocyanate was added and heated to 60 ° C., followed by three hydroxyl groups, WRG-7000 (WR.Grace & Co.) A small amount of 1315 g was added to polymerize until the theoretical NCO% was reached. Samples were taken in the middle of the reaction to measure NCO%, and NCO% was determined by titrimetry using n-butylamine standard solution.

The foam dressing material was added to 50% by weight of the polyurethane prepolymer synthesized as described above, 48% by weight of distilled water and 2% by weight of F-68 were stirred at high speed at 3,000 to 5,000 rpm, and then the mixture was cast and the film was laminated on both sides. Prepared.

Physical properties were measured by the method exemplified in Example 1, and the experimental results are shown in Table 1 below.

[Table 1] Measurement results of the physical foam dressing material produced

As shown in Examples 1, 2, and 3 of Table 1, when the NCO% of the polyurethane prepolymer and the amount of glycerin as a crosslinking agent were increased, the urethane bond (hard segment) increased, and the mechanical properties increased and the relatively hydrophilic part (soft segment). ), The absorbance decreases. It can be seen that the swelling degree can be adjusted according to the content ratio of the hydrophobic polypropylene glycol and the hydrophilic ethylene oxide / propylene oxide random copolymer used in preparing the polyurethane prepolymer in Example 4. That is, as the content of the ethylene oxide / propylene oxide random copolymer increases, the absorbency increases. The foam dressing material of the present invention, as can be seen in Figure 2, the epidermal layer is in the form of a thin film having a pore (pore) of 3 to 60㎛ diameter, the inner layer is an open cell structure of 50 to 500㎛ diameter It consists of a foam, and from these structural features it can be seen that the absorbency and moisture permeability is higher than the existing product (Comparative Example 1). Therefore, it is possible to further absorb the exudates following the permeable release of the absorbent exudates and to apply to wounds in which a large amount of exudates are generated for a long time.

In animal experiments, the foam dressing material (Example 1) of the present invention showed that the number of living cells decreased by 7% and 30% for the control cell number after 1 day and 3 days, respectively, and showed superior survival rate compared to Comparative Example 1. And showed excellent biocompatibility compared to the comparative example. In addition, as a result of animal experiments, the control and the existing products were wound healing proceeded by shrinkage and crust was formed, but the foam dressing material of the present invention progressed the wound healing by re-epithelialization without the formation of the peel and wound. The restoration period has been dramatically shortened.

As described above, the foam dressing material of the microporous epidermal structure of the present invention has an inner cell having an open cell having a diameter of 50 to 500 μm between the two skin layers and a double skin layer having a large number of pores of 3 to 60 μm in diameter. It is composed of a foam layer, and its structural characteristics prevent the invasion of foreign substances and bacteria, and it is possible to apply as a general-purpose foam dressing material having high moisture permeability, high water absorption, non-adhesion of wound surface and having excellent wound healing effect in a wet environment.

Claims (4)

In a closed foam dressing material for use as a wound coating material, an interior having a double-sided skin layer (1) having a micropore (2) having a diameter of 3 to 60 µm and an open cell (4) having a diameter of 50 to 500 µm between the two skin layers. Microporous foam dressing material, characterized in that the foam layer (3). The microporous foam dressing material according to claim 1, wherein the foam dressing material has a thickness of 1 to 7 mm. 2. The microporous material according to claim 1, wherein the area of the microporous layer 2 of the skin layer 1 is 5 to 50% of the total skin layer area and the open cell 4 ratio of the inner foam layer 3 is 80% or more. Foam dressings. The microporous foam dressing material according to claim 1, wherein the water absorption is 500 to 1,500% by weight and the water vapor transmission rate is 1,500 to 9,000 g / m 2/24 hrs.