FI95207C - Wound Protective Side - Google Patents

Description

1 - 95207

This invention relates to a wound dressing containing microcrystalline chitosan.

5

Chitosan is a partially or completely deacetylated chitin, also known by its chemical name poly (N-acetylglucosamine). Chitin forms the hard shell of crustaceans and insects as well as the cell-10 walls of fungi. Chitosan is known by its chemical name poly (2-deoxy-2-aminoglucose). The preparation of chitin and chitosan and their properties are described in "Chitin", Pergamon Press, New York, 1977.

15 Microcrystalline chitosan is a specific physico-chemical form of standard chitosan and is produced by a special aggregation system. In the Journal of Applied Polymer Science, Vol. 33, p. 177, 1987 and the product according to the above-mentioned method described in Polish Patent 125995 and Finnish Patent 83426 exist as a gel-like dispersion or powder.

The microcrystalline chitosan11a obtained by the above-mentioned methods had a water retention value of WRV in powder form between 200 and 500% and in dispersion form between 500 and 5000%, an average molecular weight suitably in the range of 104 to 106 and a degree of deacetylation of at least 30%.

Japanese Patent Application 63182304 discloses a microcrystalline chitosan which is only a powder and has only a low water retention value of up to 100% and which is obtained by acid hydrolysis of standard chitosan in organic solvents.

Finnish patent 77681 describes a process for making films from a dispersion of microcrystalline chitosan 35, 95207, in particular in an aqueous or organic medium, by pouring onto a substrate, preferably a fibrous, plastic, glass or metal mold, and then drying and removing from the substrate. The film of the invention 5 is also formed by filtering microcrystalline chitosan on a filter medium using a reduced pressure.

Chitin, chitosan and their derivatives have been found to be very active in the field of wound healing. In human clinical trials with several forms of these polymers, such as powder, chitosan saline, fibers, non-woven fabrics, sponges, coated sutures, and excipients, acceleration of healing was observed with faster healing as well as slow healing and poor healing. The results of medical tests that confirmed the efficacy of polyaminosaccharides in accelerating wound healing were presented in "Chitin", Pergamon Press, New York, 1977, INFOFISH International, Vol. 5, pp. 317, 1987, "Chitin, Chitosan and Related Enzymes", Academic Press Inc., Orlando, 1984, "Chitin in Nature and Technology", Plenum Press, New York, 1986, Proceedings of 1-4 Interna-25 tional Conference on Chitin / Chitosan, 1978, 1982, 1986, 1988, Medycyna Lotnieza, vol. 1 (90), p. 40 (1986), as well as U.S. Patents 3,624,201, 3,632,754, 3,911,116, 4,574,450 and 4,572,906, European Patents 0138,385, 0200574, 0291587, Japanese Patents 79100059, 79161525, 30 60142927, 61141373, 62048073 and 63090507.

Chitin and chitosan are physiologically acceptable bioabsorbable and effective at a wound healing rate of 35. Polyamine saccharides, especially chitosan, which have physiological compatibility with living tissues combined with their non-thrombogenic property, appear to make it the most promising material for a prosthetic structure of any shape and size. Chitosan has also been used effectively to treat certain types of infections.

5 European Patent Application 0277322 from Wella AG discloses a cosmetic preparation for the treatment of hair or skin based on N-hydroxypropyl ether derivatives of standard chitosan. This composition can be mixed with a propellant, liquefied under pressure, filled into a pressure vessel, and used as an aerosol spray or foam or as a hair shampoo.

European Patent Application 0272472 also discloses a suitable cosmetic composition based on a salt of standard dicycitosan and a copolymer of acrylic acid and methacryloxyethyltrimethylammonium chloride, prepared as water / alcohol-based solutions, ointments, dispersions, gels, dispersions.

20

Japanese Patent 61073655 discloses a wound protection film using a solution containing anionic or cationic macromolecular compounds selected from xanthan gum, alginic acid, galacturonic acid or standard chitosan salts, polylysine, and. among a copolymer of dihydroxyethylaminopropyl and glutamic acid.

The compositions in the form of solutions are injected into the wound and the surrounding area. The developed membrane had good adhesion to the skin, resulting in wound protection and: the gauze did not need to be applied to the wound.

Japanese Patent 83247995 also discloses pharmaceutical patches containing water-soluble standard dicitosan salts that can be used to treat damaged parts of the mouth, nasal cavity or vagina.

4 95207

The effect of chitosan in wound healing and the treatment of burns is described in Neurosurgery, Vol. 15. Page 9 (1984) and Polymers in Medicine, Plenum Press,

London, 1984. Chitosan in contact with the erythrocyte membrane 5 forms a hemostatic clot that withstands arterial pressure in the capillaries and results in the growth of soft muscle in the vessel wall in the endothelial intima. The chitosan used to treat various tissues results in the inhibition of fibroplasma and the regeneration of normal tissue elements. Assuming that the availability of abundant lysozyme at the wound would gradually degrade chitin or chitosan to the active N-acetyl-D-glucosamine dimer and be responsible for its sustained release, it was decided to investigate the use of polyaminosaccharides in wound healing.

Known wound dressings contain standard chitosan in the form of organic or inorganic salts soluble in water or dilute organic acids, or derivatives of chitin and chitosan which are soluble in water or organic solvents. The preparation of chitin or chitosan derivatives requires special complex techniques and involves problems in handling and purification. The salt of standard chitosan 25, which is soluble in water and dilute organic acids and also has an acidic reaction, usually at a pH of 3-5, causes an irritation or an allergic reaction at the wound healing or burn site. The film of the standard chitosan salt formed on the skin is not water resistant and is readily soluble in wash water or moisture. This type of dressing • requires multiple repetitions to achieve proper healing.

It is an object of the present invention to provide a wound dressing which can be produced from a composition containing microcrystalline chitosan as a gel dispersion, in particular in a volatile organic medium such as ethyl alcohol or diethyl ether, optionally mixed with a propellant such as propane-butane or fluorinated hydrocarbons. , filled into a pressure vessel and used as an aerosol spray or foam on wounds and the surrounding area.

According to the present invention, there is provided a wound dressing formed on a wound as a polymeric dressing, characterized in that the dressing is a microcrystalline chitosan which produces a suitable porous adhesive film.

According to a preferred embodiment of the invention, the product contains before use 0.1 to 10% by weight of chitosan in microcrystalline form and 90 to 99.9% by weight of neutral substances, such as propellant, e.g. propane-butane, fluorocarbons, volatile organic medium and / or water, possibly at a suitable pressure.

20

According to a preferred embodiment of the invention, after application to the wound and the surrounding area, the product generates, by evaporation of a volatile organic medium and / or water, a porous, adhesive film containing 60 to 95% by weight of chitosan in microcrystalline form. being mainly water.

According to a preferred embodiment of the invention, the evaporation of the volatile organic medium and / or water from the product formed on the wound 30 and the surrounding area takes place in at least 20 seconds at normal temperatures of the human body.

According to a preferred embodiment of the invention, the microcrystalline chitosan used as a base material for the wound dressing as a neutral gel dispersion has a water retention WRV in the range of 500 to 5000%, an average molecular weight in the range of ΙΟ3 to 106, a Dease degree of at least 30%, preferably in the range of 0.01 to 100 μιη. Furthermore, it preferably has a medical purity with a heavy metal content of less than 10 ppm, an ash content of less than 0.5% by weight and a bacterial content according to NF standards XII and XIV.

The wound dressing of the invention forms a polymer film upon drying of the microcrystalline chitosan dispersion.

This film contains 60-95% by weight of chitosan in the form of a microcrystalline polymer, the remainder being mainly water.

According to a preferred embodiment of the invention, the microcrystalline chitosan used as a base material for the wound dressing as a gel dispersion is solvent-exchanged with a volatile organic medium such as ethyl alcohol or diethyl ether from an aqueous dispersion of this microcrystalline chitosan.

It is also an object of the invention to provide a wound dressing which can be obtained from a composition comprising microcrystalline chitosan in gel dispersion and other film-forming natural polymeric material such as sodium and / or calcium alginate, cellulose derivatives such as sodium carboxymethylcellulose, in particular in the form of a solution or dispersion. in a volatile organic medium such as ethyl alcohol and / or diethyl ether, optionally mixed with a propellant such as propane-butane, fluorinated hydrocarbons or alcohol, filled into a pressure vessel and applied as an aerosol spray or foam to wounds and the surrounding area.

• «

According to the invention, there is provided a wound dressing which is formed on a wound as a polymeric dressing, characterized in that the dressing is a mixture of microcrystalline chitosan and other film-forming natural polymeric materials which produces a suitable porous adhesive film.

According to a preferred embodiment of the invention, the composition 5 contains before use 0.05 to 10% by weight of chitosan in the form of microcrystalline chitosan, 0.01 to 10% by weight of other natural polymeric materials and 80.0 to 99.4% by weight of neutral substance, such as propellant, ethyl alcohol, diethyl ether and / or water, optionally at a suitable pressure.

According to a preferred embodiment of the invention, the composition contains microcrystalline chitosan in the form of a neutral gel dispersion characterized by a water retention capacity of WRV 500-5000%, an average molecular weight in the range 103-106, at least 30%, preferably 50-90% deacetylation, particle size preferably in the range 0, 01 - 100 .mu.m. The composition preferably has the aforementioned degree of medical purity.

20

According to a preferred embodiment of the invention, the product containing microcrystalline chitosan in the form of a gel dispersion is solvent-exchanged with a volatile organic medium such as ethyl alcohol and / or diethyl ether from an aqueous solution of this microcrystalline chitosan.

Natural polymeric materials can be added to the microcrystalline chitosan composition before, during and / or after the solvent exchange process.

30

According to a preferred embodiment of the invention, the product • after application to the wound and the surrounding area generates by evaporation of a volatile organic medium and / or water a porous, adhesive film containing 35 50-95% by weight of chitosan in microcrystalline form in admixture with other natural polymeric materials.

8 95207

According to a preferred embodiment of the invention, the evaporation of the volatile organic medium and / or water from the product forming the wound area of the film takes place in at least 20 seconds at normal temperature of the human body.

5

The wound dressing of the invention in a pharmaceutical aerosol spray or foam composition is a mixture of microcrystalline chitosan in the form of a gel dispersion, usually in a volatile organic medium such as ethyl alcohol or diethyl ether, optionally also containing a propellant such as propane-butane or a fluorine mixture or fluorine. This composition containing 0.1 to 10% by weight of microcrystalline chitosan is in neutral form containing 15 free amino groups.

A dispersion of microcrystalline chitosan of medical purity makes it possible to obtain a wound dressing in the form of an aerosol spray or foam.

The ability of microcrystalline chitosan agglomerates to form a stable dispersion in an aqueous or organic medium. Their biostability in this form makes it possible to prepare a new type of previously unknown aerosol dressing containing chitosan-25. The unique behavior of the microcrystalline chitosan dispersion forms an adhesive polymer film suitable for the skin, which acts as a wound dressing without further treatment, with the exception of simple drying.

30 Other natural film-forming polymers, such as sodium and / or calcium alginates or cellulose derivatives. the addition of women such as carboxymethylcellulose ♦ * to a mixture with a gel-like dispersion of microcrystalline chitosan improves the behavior and properties of the obtained film, such as oxygen permeability, flexibility, strength and elongation. At the same time, the liquid mixture of microcrystalline chitosan with other natural polymeric materials is characterized by better viscosity and behavior in film formation.

The wound covering film is also characterized by other useful properties, such as a greater ability to break the hemostomy in the event that the product contains calcium alginate.

The wound dressing of the invention does not cause irritation or an allergic reaction on the skin, wound and surrounding area. The composition of the invention contains only natural biodegradable polymer as microcrystalline chitosan and an organic medium such as ethyl alcohol or diethyl ether which is acceptable to the human body at a neutral pH.

After use, the wound dressing of the invention forms a porous, oxygen-permeable film on the skin, wound and surrounding area that protects 20 wounds from infection and other external threats.

The wound to be healed with a bandage may result from injury, surgery, fire, etc.

The wound dressing covers all wound sites and the surrounding area with an adhesive film, which is an elastic, biodegradable polymeric film that is subject to biodegradation by human body enzymes. The microcrystalline chitosan-based wound dressing is known to degrade by chitinase enzymes, especially lysozyme, which is transported to wound sites by inflammatory cells - polymorphonuclear. .. via leukocytes. Lysozyme gradually breaks down chitosan at the wound site into the active N-acetyl-D-glucosamine dimer and ensures its continuous release.

The wound dressing is waterproof and washable.

The great flexibility of this wound dressing and its good • ·.

The mechanical properties of 95207 allow this dressing to be applied to all types of wounds in the human body, especially to specific areas such as hands, feet, etc. The wound dressing of the invention forms a polymer film characterized by an energy of hydrogen bonds between 10 and 20 kJ / mol.

The wound dressing according to the invention, which is formed by drying a mixture containing a dispersion of microcrystalline chitosan, requires at least 20 seconds, in particular 20-60 seconds, for the formation of a suitable film.

The wound dressing of the invention in the form of a dispersion of microcrystalline chitosan is stable for at least one year.

15

The aim is to further develop a microcrystalline chitosan-based wound dressing that can be used in medicine, medicine or cosmetics.

20

The following methods have been used to determine the properties of microcrystalline chitosan, other natural polymeric materials and wound dressings: 25 - crystallinity index IKX: in Textile Research

Journal, vol. 29, p. 786, 1959, - degree of deacetylation of chitosan: in the International Journal of Biological Macromolecules, vol. 2, p.

115, 1980, - hydrogen bonding energy EH: in Cellulose Chemistry and Technology, vol. 7, p. 173, 1973, "95207 - water retention WRV: according to the method described in Cellulose Chemistry and Technology, vol. 11, p. 633, 1977, * 5 - average molecular weight of chitosan: in" Chitin ", According to the method described by Pergamon Press, New York, 1977, - medical purity of microcrystalline chitosan: 10 according to International Standards NF XII and NF XIV of the National Formulation.

The additives used were: 1. A gel-like dispersion of microcrystalline chitosan obtained according to Polish patent 125995. A dispersion of microcrystalline chitosan in an organic medium such as ethyl alcohol or diethyl ether was also prepared by a solvent exchange method.

2. Film-forming natural polymeric materials such as sodium alginate, calcium alginate or sodium carboxymethylcellulose as a powder to form suitable solutions or also dispersions in a mixture with a gel-like dispersion of microcrystalline chitosan.

3. Ethyl alcohol or diethyl ether as an organic medium for the dispersion of microcrystalline chitosan.

30 4. For the preparation of an aerosol spray or foam, a propellant in the form of propane-butane, fluorinated hydrocarbons or alcohol.

The invention is further illustrated by the following examples, which do not limit the scope of the claims.

12 95207

Example 1.

100 parts of a gel dispersion of microcrystalline chitosan in ethyl alcohol containing 2.5% by weight of a polymer characterized by a WRV of 800%, an average molecular weight of 4.2 x 10 5, a degree of deacetylation of 75%, a medical purity, a particle size in the range of 0.1 to 20 μm and pH 7.1 of the dispersion, was added to a pressure vessel and filled with 5.5 parts by weight of a propane-butane mixture.

The aerosol composition of microcrystalline chitosan was sprayed onto the wound and formed a porous, adhesive and elastic chitosan film in 207 seconds, characterized by a bond EH of 20.8 kJ / mol and a crystallinity index IKj of 0.38. Clinical tests showed that this wound dressing is not allergic and does not cause irritation.

20

Example 2.

50 parts by weight of a gel-like dispersion of microcrystalline chitosan in ethyl alcohol having the same properties as in Example 1 was added to the pressure vessel 4.0: part by weight of a propane-butane mixture.

The aerosol composition of microcrystalline chitosan was sprayed onto the wound and formed a porous, adhesive and elastic chitosan film with a thickness of 0.05 mm, a hydrogen bond energy EH of 9.3 kJ / mol and a crystallinity index IKj of 0.05 in 62 seconds. Clinical tests have shown that this wound protection is not allergic and does not cause irritation.

25 13 95207

Example 3.

25 parts by weight of a gel-like dispersion of microcrystalline chitosan in ethyl alcohol containing 1.9% by weight of a polymer characterized by WRV 1010%, average molecular weight 2.3 x 10 5, degree of deacetylation 85%, medical purity, particle size in the range 0.1 to 25 / un and the pH reaction of the dispersion 7.0 was added to the pressure vessel 10 with 3.5 parts by weight of a propane-butane mixture.

The aerosol composition of microcrystalline chitosan was sprayed onto the wound and formed a chitosan film of porous, adhesive and elastic wound dressing in 33 seconds, and was characterized by 0.08 mm thickness, hydrogen bond energy EH 19.4 kJ / mol and crystallinity index ΙΚ2 0.7.

Clinical tests showed that this wound dressing is not allergic and does not cause irritation.

20

Example 4.

10 parts by weight of a gel-like dispersion of microcrystalline chitosan in ethyl alcohol having the same properties as in Example 1 was added to the pressure vessel with 4.0 parts by weight of a propane-butane mixture.

The aerosol composition of microcrystalline chitosan was sprayed onto the wound and formed a chitosan film of porous, adhesive and elastic wound dressing in 22 seconds and was characterized by a thickness of 0.04 mm, water. ^ bond energy EH 23.7 kJ / mol and crystallinity index ΙΚΧ 0.4. Clinical tests have shown that this wound dressing is not allergic and does not cause irritation.

35 14 95207

Example 5.

28 parts by weight of a gel-like dispersion of microcrystalline chitosan in ethyl alcohol with the same properties as in Example 1 were added to the pressure vessel with 6.0 parts by weight of fluorinated hydrocarbons.

The aerosol composition of microcrystalline chitosan was sprayed onto 10 wounds and formed a chitosan film of porous, adhesive and elastic wound dressing in 110 seconds, characterized by a thickness of 1.2 mm, a hydrogen bond energy EH of 20.1 kJ / mol and a crystallinity index IKj of 0.33. Clinical tests showed that this wound-15 dressing is not allergic and does not cause irritation.

Example 6.

30 parts by weight of a gel 20 dispersion of microcrystalline chitosan in diethyl ether containing 24% by weight of a polymer characterized by a WRV of 2100%, an average molecular weight of 2 x 104, a degree of deacetylation of 87%, a medical grade, a particle size in the range of 0.1-5. reaction 7.0, 2.0 parts by weight of ethyl alcohol were added to the self-pressure vessel.

The foamy composition of the microcrystalline chitosan aerosol was sprayed onto the wound and formed a chitosan film of porous, adhesive and elastic wound dressing 30 in 95 seconds and was characterized by a thickness of 1 mm, a hydrogen bond energy EH 8-10 kJ / mol and a crystallinity index IKT 0.1. Clinical tests showed that this wound dressing is not allergic and does not cause irritation.

35 • I 4%

Example 7.

95207 <50 parts by weight of a gel-like dispersion of microcrystalline chitosan in water, characterized by a polymer content of 3.27% by weight, a water retention of 1280%, an average molecular weight of 1.28 x 10 5, a degree of deacetylation of 69.5%, a particle size in the range from 1 to 20 μτα, pH reaction of the dispersion 7.0 and medical grade, the solvent was changed twice using 100 volumes of ethanol each time, and that solvent was changed once with diethyl ether using 100 volumes of diethyl ether. The polymer was then filtered to give a polymer content of 425% by weight.

15

Microcrystalline chitosan was added to self-pressure vessels with 25 volumes of a 1: 1 mixture of ethyl alcohol and diethyl ether.

The foam composition of the microcrystalline chitosan aerosol was sprayed onto the wound and formed a porous, adhesive and elastic chitosan film covering the wound and the surrounding area with a thickness of 0.8 mm in 75 seconds, a hydrogen bond energy EH 12 of 25 kJ / mol and a crystallinity index IKj 0, 28. Clinical tests showed that this wound dressing is not allergic and does not cause irritation.

Example 8.

50 parts by weight of an aqueous dispersion of microcrystalline chitosan, the properties of which are described in Example 7, were stirred for 2 hours with 0.16 parts by weight of sodium al-. ginate, and then the resulting mixture was homogenized at 35,500 r.p.m for 5 minutes. A mixture of microcrystalline chitosan and sodium alginate was added to automatic pressure vessels with 50 volumes of diethyl ether.

16 95207

The product was sprayed onto the wound and formed in 30 seconds a porous, highly flexible and adhesive film covering the wound area with a thickness of 0.2 mm, a hydrogen bond energy EH of 15 kJ / mol and a crystallinity index IKX of 0.08.

Clinical tests showed that this wound dressing is not allergic and does not cause irritation.

10 Example 9.

A mixture of the aqueous dispersion of microcrystalline chitosan and sodium alginate as described in Example 8 was added to the pressure vessels with 8 parts by weight of a propane-butane-15 mixture.

The composition of microcrystalline chitosan and alginate was sprayed on the wound and formed a porous, highly elastic and adhesive film in 50 seconds, which protected the wound-20 region and was characterized by a thickness of 1.0 mm, a hydrogen bond energy EH of 16.2 kJ / mol and a crystallinity index ΙΚτ 0, 10.

Clinical tests showed that this wound dressing 2b is not allergic and does not cause irritation.

*

Example 10.

50 parts by weight of an aqueous dispersion of microcrystalline chitosan, the properties of which are described in Example 7, were subjected to a solvent exchange treatment using 100 ml of ethyl alcohol. Thereafter, 1.45 parts by weight of powdered calcium alginate was added with stirring for 3 hours and homogenized at 1000 r.p.m for 10 minutes. The product, which was characterized by a dry matter content of 5.2% by weight, was added to self-pressurized containers with 10 volumes of I * H * »Iti I M« - it 95207 ethyl alcohol. The composition of microcrystalline chitosan and alginate was sprayed on the wound and formed a porous, highly elastic, calcium alginate-containing chitosan film in 68 seconds and was characterized by a thickness of 0.5 mm, a hydrogen bond energy EH of 14.8 kJ / mol and a crystallinity index IKj of 0.12. .

Clinical tests showed that this wound dressing is not allergic and does not cause irritation. At the same time, an antihemostomy effect was observed.

Example li.

50 parts by weight of an aqueous dispersion of microcrystalline chitosan, the properties of which are described in Example 7, was subjected to a solvent exchange treatment as in Example 10. 1.50 parts by weight of ethanol-soluble sodium carboxymethylcellulose were then stirred for 4 hours and homogenized at 800 r.p.m. The product 20, which was characterized by a dry matter content of 6.2% by weight, was added to self-pressure vessels with 50 volumes of ethanol.

The product was sprayed on the wound and formed a porous, highly elastic and adhesive film with a thickness of 0.5 mm, a hydrogen bond energy EH of 17.8 kJ / mol and a crystallinity of 0.30 for 45 seconds.

Clinical tests showed that this wound dressing? 0 is not allergic and does not cause irritation.

“· ·%

Claims (12)

18 95207 A wound dressing comprising chitosan as a base material, characterized in that the chitosan is microcrystalline chitosan containing free amino groups in the form of a gel dispersion in a neutral composition in which the carrier fluid is volatile at human or animal body temperature, the microcrystalline chitosan being able to form a suitable solvent. porous adhesive film. 2. A method for cleaning a microcrystal according to claim 1, wherein the microcrystalline crystals have been used in the form of a mixture of three and the same type of propellant, for which the propellant is used as an aerosol. och omgivande omräden. A wound dressing according to claim 1, characterized in that the microcrystalline chitosan is included in a pressure vessel in the composition together with a carrier and a propellant such as a propane-butane mixture for use as an aerosol spray or foam on the wound and surrounding areas. 3. A compound for the preparation of a patented composition 1 or 2, 20 turns of which is a suitable organic medium, preferably ethyl alcohol or diethyl ether. Wound dressing according to Claim 1 or 2, characterized in that the carrier liquid contains a volatile organic medium, such as ethyl alcohol or diethyl ether. 4. The method for measuring the face of a patent according to claims 25 1-3, the first step is shown in the foregoing. användning innehäller 0,1-10 vikt-% kitosan i microcrystalline form and 90,0-99,9 vikt-% neutrala ämnen, säsom bärarvätska och drivmedel. 30 5. Förband för särskydd enligt segot av patentkraven 1-4, kännetecknat därav, att mossätättningens innehäll är sädant, att den efter spridning head säret och de omgivande omräden bildar genom avdunstningen av bärarvätskan en porös vidhäftande ár, 95% by weight of the crystal in the form of microcrystals. 95207 Wound dressing according to one of Claims 1 to 3, characterized in that the composition contains, before use, 0.1 to 10% by weight of chitosan in microcrystalline form and 90.0 to 99.9% by weight of neutral substances such as carrier liquid and propellant. 30 Wound dressing according to one of Claims 1 to 4, characterized in that the composition is such that, after application to the wound and the surrounding areas, it forms a porous adhesive film containing 60 to 95% by weight of chitosan in microcrystalline form, the remainder being mainly water. . 95207 6. A method for shining a film according to claims 1-3, which can be used as a microcrystalline crystal, in which case a film of natural polyolymeric material is used, the sodium 5 och / cellulose alginate or a cellulose acid. Wound dressing according to one of Claims 1 to 3, characterized in that the microcrystalline chitosan is present in a composition containing another film-forming natural polymeric material, such as sodium and / or calcium alginate, or a cellulose derivative, such as sodium carboxymethylcellulose. 7. Förband förskydd enligt patentkravet 6, känne-tecknat därav, at samansättningen innehäller före 10 användning 0.05-10 wt.% Chitosan in microcrystalline form, 0.01-10 wt.% Det andra natympolymermaterialet i form av en lösning eller dispersion och 80,0 - 99,94 vikt-% neutrala ämnen, säsom bärarvätska och drivmedel. 15 Wound dressing according to Claim 6, characterized in that the composition contains, before use, 0.05 to 10% by weight of chitosan in microcrystalline form, 0.01 to 10% by weight of other natural polymeric material in the form of a solution or dispersion and 80.0 to 99%, 94% by weight of neutral substances such as carrier liquid and propellant. 8. The method of applying the provisions of claims 6 or 7, comprising the same conditions, having the same value as the first part of the patent, the value of which is shown in paragraph 50, the price of which is not more than -% chitosan in the form of microcrystals Medan racks are of interest in water and detects the appearance of natural polymeric materials. 25 9. Förband förskydd enligt segot av patentkraven 1-8, kännetecknat därav, att mossessätningens innehäll är sädant, att avdunstningen av bärarvätskan frän mossättningen ända account filmbildningen varar minst 20 sekunder vid en temperatur av 36 ... 38 ° C. 30 Wound dressing according to Claim 6 or 7, characterized in that the composition is such that, after application to the wound and the surrounding areas, it forms by evaporation of the carrier liquid a porous, adhesive film containing 50 to 95% by weight of chitosan in microcrystalline form. being primarily water and other film-forming natural polymeric materials. Wound dressing according to one of Claims 1 to 8, characterized in that the content of the composition is such that evaporation of the carrier liquid from the composition to film formation takes at least 20 seconds at a temperature of 36 to 38 ° C. 10. The method for applying a shield according to the invention: 1-9, in turn, in the form of a microcrystalline chitosan, which comprises a base material and in the form of a neutral gel dispersion, a watten-35 binding form with a WRV of 500-5000%, molecules in omelets 103-106, deacetylerification graden. av minst 30%, företrädesvis 50-90%, partikelstorleken företrädesvis i omrädet 0,01-100 μιη. 23 9 5 2 0 7 Wound dressing according to one of Claims 1 to 9, characterized in that the microcrystalline chitosan in the form of a neutral gel dispersion used as base material has a water retention capacity WRV in the range from 500 to 5000%, an average molecular weight in the range from 103 to 106, a deacetylation degree of at least 30%, preferably 50 to 90%, particle size preferably in the range of 0.01 to 100 μm. 95207 11. A method for producing a microcrystalline crystal according to claim 10, which is provided as a microcrystalline medium for medical treatment, in which the color is preferably 5 to 10% by weight, preferably less than 0.5% by weight and bacterial in vivo XII. Wound dressing according to Claim 10, characterized in that the microcrystalline chitosan used has a medical purity with a heavy metal content of less than 10 ppm, an ash content of less than 0.5% by weight and a bacterial content of standards NF XII and XIV. Wound dressing according to Claim 3 and one of Claims 4 to 11, characterized in that it is prepared by using solvent exchange with a volatile organic medium, such as ethyl alcohol or diethyl ether, from an aqueous dispersion of microcrystalline chitosan. • · I 95207. 1. A method for reducing the amount of microcrystalline material in the form of a microcrystalline crystal dispersion in a neutral temperature setting, in which case the temperature of the microcrystalline medium is reduced to a minimum of linen kitosanen förmär bilda en warm plastic watten 10 porös vidhäftande cena under avdunstningen av bäraren. 12. A process for the preparation of a compound according to claims 3 and 10 according to claims 4-11, which can be used to prepare a genome-containing solvent by means of an organic medium, an ethyl alcohol or a diethyl ether, in the form of a water crystal dispersion. 15 «§ *