JPS6325783B2 - - Google Patents

Description

[Detailed Description of the Invention] JP-A No. 54-5023 particularly describes wound treatment,
In addition, post-treatment of skin tumors, desensitization of allergies,
A transparent liquid dressing material suitable for cosmetic purposes, moisture retention in exposed bones and tendons, psoriasis, and as a medium for cell culture is described, which is characterized by consisting of a hydrophilic organic transparent gel in the form of paper leaves or strips, which gel It is present in a swollen state with an aqueous solution which may contain buffering substances, active substances customary for wound treatment, nutrients or/and growth factors, and optionally contains reinforcing material arranged in a number of rows or networks. The special advantages of this dressing material are that it is particularly easy to apply, can be removed or replaced without any hindrance, allows visual observation of the underlying body part or cell culture, and allows wound healing without excessive granuloma formation. The goal is to improve this and make it possible to add active substances through the material. The storage of this transparent liquid dressing material may be disadvantageous due to its high liquid content. Moreover, the supply of active substances and the removal of secretions require relatively long periods of time. It is therefore an object of the present invention to retain all the advantages of a transparent liquid dressing material, while also obtaining it in an easy-to-storage form that allows rapid delivery of active substances and drainage of secretions. This object is solved by the present invention. That is, the present invention consists of a hydrophilic, transparent organic gel in the form of paper sheets or bands consisting of agarose or gelatin and a polymeric acrylamide or methacrylic acid amide. Transparent liquid dressing material produced by polymerization of acid amides, characterized in that the material is present as a dry, swellable transparent sheet. The dressing material of the present invention exists in the form of a very thin glass-like transparent sheet and has a very high reswelling capacity, absorbing more than 10 times its weight in liquid within a short period of time, i.e. about one hour; It is then re-dried almost completely while recovering all the mechanical and structural properties of the swollen starting material. Generally, the weight of the dry sheet is between 2 and 2 of the weight of the swollen water-containing starting material.
10%, especially 3-7%. The thickness is generally about 0.5~0.01mm measured without reinforcing material, especially 0.3~
It is 0.003mm. As in the case of said publication, the gel may consist of 10 to 90% by weight of the polymers acrylic amide or methacrylic amide and 90 to 10 % by weight of agarose or gelatin. However, particularly favorable drying and reconstitution properties may be obtained when the polymeric acrylic amide or methacrylic amide is present in at least an equal weight to the agarose or gelatin, especially between 60 and 90% by weight of the total gel dry matter. It became clear. The production of the dressing material of the present invention is carried out in the same manner as in the above-mentioned publication. That is, the monomer or monomer mixture and at least one gelatable hydrophilic polymeric substance are dissolved in an aqueous medium as starting materials for gel preparation, the solution is given the desired thickness as a sheet or strip material, and then the polymerizable The gel-forming reaction is initiated by addition of a monomer polymerization initiator or initiator mixture, optionally reinforcing material being inserted before, during or after addition of the initiator, and the swollen gel is then dried. Drying is advantageously carried out uniformly and simultaneously from both sides.
Drying must be carried out in such a way as to avoid distortions, such as the generation of waves, during the process. This is achieved by drying the gel between two porous supports according to the method of implementation of the invention. Suitable supports are, for example, porous plastic plates, perforated metal plates or sheets. If the porous support is used in the form of a relatively thin sheet, the sheet itself is again supported by a suitable support structure. According to another embodiment of the invention, the hydrogel is applied to a reinforcing material in the form of rows or networks and dried in this form. The drying itself is carried out at room temperature or at elevated temperatures under vacuum or normal pressure. When using the aforementioned sandwich method of drying between two porous supports, a vacuum of 1 to 10 mmHg can be used;
It was thereby confirmed that the properties of the dried sheet were not significantly impaired in terms of recovery of the mechanical and structural properties of the hydrous starting material. If drying is not carried out without a vacuum, for example with hot air, the support is preferably a metal plate or sheet in order to improve the heat transfer. It has been found that gels with an initial thickness of 0.5 to 3 mm are particularly suitable for drying. The best results when using porous supports are achieved with gels of 1-2 mm thickness, where in this range with increasing thickness the application of vacuum gives better properties than without vacuum. It will be done. When drying with hot air rather than vacuum, best results are achieved with a thickness of 1 mm or less. The present invention achieves a significant improvement over the above-mentioned publication. For example, dry bandage sheets eliminate packaging difficulties and are significantly easier to maintain sterile. On the other hand, gels that are already saturated with water absorb active substances, such as antibiotics, cytostatics, wound hormones, nutrients, etc., only relatively slowly. This is because an exchange of the external liquid and the liquid contained in the gel must take place. In the case of the drying method according to the invention, this exchange is significantly accelerated, since the aqueous solution containing the active substance is directly absorbed. Finally, the dressing material according to the invention in dry form is particularly suitable for highly secreting wounds without prior reswelling or with only partial reswelling. This is because secretions are sucked out significantly more than in a fully swollen material. In this way it is possible to draw out the same amount of secretion as can be achieved in the case of the dressing material of said publication only by means of drainage holes in the material. The invention will now be explained by way of example. Examples 1 to 6: The gel is made of polyacrylamide (3.5%) as described in Example 2 of JP-A-54-5023.
and agarose (2%). For this, add 3.5 g of acrylamide and 91 mg of methylenebisacrylamide to 50 ml of distilled water.
dissolve in Dissolve 2 g of agarose in 50 ml of distilled water at 100°C in a water bath, cool to 60°C,
After adding 60μ of N′,N′-tetramethylenediamine and 45mg of ammonium peroxodisulfate,
Mix well with the acrylamide solution and immediately spread onto a 12.5 x 26 cm prospective glass plate with a rim height of 2 mm and close with a glass lid. After holding at 56°C for 30 minutes and confirming the polymerization of acrylamide, the glass plate is then aged at 4°C for at least 24 hours. After removal, the gel is washed several times in phosphate buffered saline to diffuse out unpolymerized material. In addition to the above composition, five other gels with different contents of polyacrylamide (P) and agarose (A) were manufactured. The composition is shown in the table below. Individual gels were made to a thickness of 1-2 mm, placed between porous plastic sheets of polyethylene, and dried at 2-5 mm Hg vacuum and room temperature.
The table shows the ratio of the wet weight of the starting material to the weight of the sheet obtained in %. Re-swelling was carried out by immersion in water. The times and degree of reswelling achieved are also shown in the table. 【table】

Claims (1)

[Scope of Claims] 1. Consists of a hydrophilic and transparent organic gel in the form of paper sheets or strips consisting of agarose or gelatin and a polymeric acrylamide or methacrylic acid amide, which gel is made of acrylamide or methacrylic acid amide in the presence of agarose or gelatin. or a transparent liquid dressing material produced by the polymerization of methacrylic acid amide, characterized in that the material is present as a dry, swellable transparent sheet. 2. A dressing according to claim 1, wherein the sheet is dry to 2 to 10% by weight of the swollen starting material. 3. A dressing according to claim 2, wherein the weight of the dry sheet is from 3 to 7% by weight of the swollen starting material. 4. The dressing material according to any one of claims 1 to 3, wherein the gel comprises 50 to 90% by weight of polymerized acrylamide or methacrylic acid amide and 50 to 10% by weight of agarose or gelatin. 5. A dressing according to any one of claims 1 to 4, comprising reinforcing material arranged in rows or in a network. 6. Acrylamide or methacrylamide and agarose or gelatin are dissolved in an aqueous medium as starting materials for gel production, this solution is brought to the desired thickness in paper sheets or strips, and then the polymerization of the polymerizable monomers mentioned above is carried out. A process for producing a transparent liquid dressing material in which the gel-forming reaction is initiated by the addition of an initiator or an initiator mixture, characterized in that the swollen gel material is subsequently dried. 7. The manufacturing method according to claim 6, in which the swollen gel is dried uniformly from both sides. 8. Claim 7 for holding the swollen gel during drying to avoid distortion during the drying process.
Manufacturing method described in section. 9. The method according to claim 8, wherein the gel is dried between two porous supports. 10. The manufacturing method according to claim 8, wherein the gel containing the reinforcing material in the form of rows or networks is spread on the reinforcing material and dried. 11. The manufacturing method according to any one of claims 6 to 10, which comprises drying a swollen gel having a thickness of 0.5 to 3 mm. 12. The manufacturing method according to any one of claims 6 to 11, wherein drying is carried out in vacuum or at high temperature. 13. The method according to any one of claims 6 to 12, wherein a reinforcing material is inserted before, during or after addition of the polymerization initiator.