# US 9,750,837 B2 · Haemostatic patch and method of preparation

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- Number: US 9,750,837 B2
- Document ID: US9750837B2
- Status: Granted
- Kind: B2
- Application number: 14/421,200
- Filed: 2013-09-25
- Published: 2015-07-23
- Granted: 2017-09-05
- Earliest claimed: 2012-09-25
- Assignees: Sofradim Production
- Applicants: Sofradim Production
- Inventors: Aurelie Serrero; Suzelei Montanari
- Web page: https://patentgrep.com/patent/US9750837B2

## CPC

- A61L 15/28: Polysaccharides or their derivatives {(A61L15/225 takes precedence)}
- A61L 15/44: Medicaments
- A61L 15/64: specially adapted to be resorbable inside the body
- B32B 37/0038: {involving application of liquid to the layers prior to lamination, e.g. wet laminating (B32B37/12 takes precedence)}
- B32B 37/1284: {Application of adhesive}
- B32B 37/24: with at least one layer not being coherent before laminating, e.g. made up from granular material sprinkled onto a substrate (B32B37/15 takes precedence)
- B32B 38/162: {Cleaning}
- C08L 1/04: Oxycellulose; Hydrocellulose {, e.g. microcrystalline cellulose}
- C08L 5/08: Chitin; Chondroitin sulfate; Hyaluronic acid; Derivatives thereof
- A61L 2400/04: Materials for stopping bleeding
- B32B 2305/026: Porous
- B32B 2317/18: Cellulose, modified cellulose or cellulose derivatives, e.g. viscose (B32B2317/10, B32B2317/12, B32B2317/16 take precedence)
- B32B 2535/00: Medical equipment, e.g. bandage, prostheses or catheter
- B32B 2555/00: Personal care
- Y10T 156/10: Methods of surface bonding and/or assembly therefor
- A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K)
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The present invention relates to a haemostatic patch comprising a porous layer based on oxidized cellulose and a neutralized film based on chitosan, said film comprising a free face and a face fixed on one of the faces of the porous layer, and to the method of preparing said patch comprising the following steps: —a°) preparing a porous layer based on oxidized cellulose, —b°) preparing a film based on chitosan starting from an acidic aqueous solution of chitosan, —c°) fixing the film obtained in b°) on one face of the porous layer, —d°) neutralizing the film obtained in b°), —where step c°) can be carried out before or after step d°), characterized in that: the neutralizing step d°) comprises treatment of said film with a neutralizing composition comprising at least ethanol and ammonium hydroxide (NH4OH).

## Claims

### Claim 1

A method of preparing a haemostatic patch comprising a porous layer including oxidized cellulose and a film including neutralized chitosan, the film comprising a first free face and a second face fixed on a first face of the porous layer, comprising the following steps:
a) preparing a porous layer including oxidized cellulose,
b) preparing a film including chitosan starting from an acidic aqueous solution of chitosan,
c) fixing the film obtained in b) on a face of the porous layer,
d) neutralizing the film obtained in b), wherein step c) is carried out before or after step d) and the neutralizing step d) comprises treating the film with a neutralizing composition comprising at least ethanol and ammonium hydroxide.

### Claim 2 (depends on 1)

The method according to claim 1, wherein step d) comprises a succession of operations of contacting at least the first free face of the film with the neutralizing composition.

### Claim 3 (depends on 1)

The method according to claim 1, wherein step d) further comprises washing the first free face of the film after treating with the neutralizing composition.

### Claim 4 (depends on 3)

The method according to claim 3, wherein the washing comprises one or more operations of rinsing at least the first free face of the film with a composition comprising ethanol and water followed by a washing with water.

### Claim 5 (depends on 1)

The method according to claim 1, wherein step c) is carried out before step d).

### Claim 6 (depends on 1)

The method according to claim 1, wherein step b) comprises pouring the acidic aqueous solution of chitosan into a mold as at least one layer, and drying the at least one layer by evaporation of water from the acidic aqueous solution to obtain the film.

### Claim 7 (depends on 6)

The method according to claim 6, wherein step c) comprises depositing the face of the porous layer of oxidized cellulose on the film prior to the drying of step b) being complete, and allowing the film to dry completely to provide fixation of the porous layer on the film.

### Claim 8 (depends on 7)

The method according to claim 7, wherein step d) comprises applying the neutralizing composition to the first free face of the film and the neutralizing composition further comprises water.

### Claim 9 (depends on 8)

The method according to claim 8, wherein the neutralizing composition consists of an ethanol/water/ammonium hydroxide mixture in a proportion of 80/16/14 by weight.

### Claim 10 (depends on 7)

The method according to claim 7, wherein step d) comprises applying the neutralizing composition on the first free face of the film one or more times using a brush.

### Claim 11 (depends on 1)

The method according to claim 1, wherein step d) is carried out before step c).

### Claim 12 (depends on 11)

The method according to claim 11, wherein step b) comprises pouring the acidic aqueous solution of chitosan into a mold as at least one layer, and drying the at least one layer by evaporation of water from the acidic aqueous solution until the film is obtained and removed from the mold.

### Claim 13 (depends on 12)

The method according to claim 12, wherein step d) comprises immersing the film obtained in step b) in the neutralizing composition.

### Claim 14 (depends on 13)

The method according to claim 13, wherein the film obtained in step b) is immersed in the neutralizing composition for 30 minutes.

### Claim 15 (depends on 13)

The method according to claim 13, wherein the neutralizing composition consists of an ethanol/ammonium hydroxide mixture in a proportion of 80/20 by weight.

### Claim 16 (depends on 13)

The method according to claim 13, wherein step c) comprises fixing the film obtained at the end of step d) on the face of the porous layer of oxidized cellulose by using a glue comprising an acidic solution of chitosan.

### Claim 17 (depends on 16)

The method according to claim 16, wherein the glue is spread on the face of the porous layer and/or on the second face of the film intended to be fixed to the porous layer, and the film is fixed to the porous layer by application of the film on the face of the porous layer with pressure.

### Claim 18 (depends on 1)

The method according to claim 1, wherein the acidic aqueous solution of chitosan of step b) further comprises a plasticizer.

### Claim 19 (depends on 18)

The method according to claim 18, wherein the plasticizer comprises glycerol.

### Claim 20 (depends on 1)

The method according to claim 1, wherein the porous layer is a textile.

### Claim 21 (depends on 1)

The method according to claim 1, wherein the porous layer is a three-dimensional knitted fabric.

### Claim 22 (depends on 1)

A haemostatic patch obtained by the method according to claim 1, comprising a porous layer including oxidized cellulose and a film including chitosan fixed to one face of the porous layer, wherein the film is in a neutralized form.