Claims for Patent: 10,363,690

Summary for Patent: 10,363,690

Title:	Method for preparing a chitosan-based porous layer
Abstract:	Method for preparing a chitosan-based porous layer The present invention relates to a method or preparing a chitosan-based, neutralized compressed porous layer, comprising the following steps: --a) a chitosan solution is prepared, --b) said solution is poured into a mold in order to form a layer, --c) the layer obtained in b) is lyophilized so as to obtain a porous layer, --d) said porous layer obtained in c) is compressed, --e) the compressed porous layer obtained in d) is neutralized by means of an NH.sub.4OH solution. It also relates to an implant comprising a layer obtained according to such a method.
Inventor(s):	Ladet; Sebastien (Caluire & Cuire, FR), Francois; Sebastien (Jassans-Riottier, FR), Claret; Julien (Villefranche sur Saone, FR), Buffin; Maud (Lyons, FR)
Assignee:	Sofradim Production (Trevoux, FR)
Application Number:	14/413,499
Patent Claims:	1. A method for preparing a chitosan-based porous layer which has been compressed, neutralized and washed, comprising the following steps: a) preparing a chitosan solution free of any other polymer, including a chitosan concentration ranging from 1.0% to 5% by weight, relative to a total weight of the solution and having a pH from 3 to 5, b) pouring the chitosan solution into a mold in order to form a layer, c) lyophilizing the layer obtained in b) to obtain a porous layer, d) compressing the porous layer obtained in c) to obtain a compressed porous layer including a density of greater than or equal to 0.65 g/cm.sup.3, e) neutralizing the compressed porous layer obtained in d) by using a NH.sub.4OH solution comprising a NH.sub.4OH concentration ranging from 0.6 to 2 mold to obtain a neutralized compressed porous layer, and, f) subjecting the neutralized compressed porous layer obtained in e) to one or more washing steps. 2. The method according to claim 1, wherein the chitosan solution prepared in step a) is a solution of chitosan in water having a chitosan concentration ranging from 2% to 3% by weight, relative to a total weight of the solution. 3. The method according to claim 1, wherein the chitosan includes a degree of acetylation ranging from 0 to 70%. 4. The method according to claim 1, wherein the chitosan includes a degree of acetylation ranging from 1% to 10%. 5. The method according to claim 1, wherein the chitosan includes a degree of acetylation ranging from 2% to 3%. 6. The method according to claim 1, wherein the solution includes acetic acid. 7. The method according to claim 1, wherein the pH is 3.5 by adding acetic acid. 8. The method according to claim 1, wherein the step of compressing the porous layer includes compressing the porous layer until obtaining a thickness of less than or equal to 2 mm. 9. The method according to claim 1, wherein the step of compressing the porous layer includes compressing the porous layer until obtaining a thickness of less than or equal to 0.5 mm. 10. The method according to claim 1, wherein the NH.sub.4OH solution used in step e) is a solution of NH.sub.4OH in water or ethanol. 11. The method according to claim 1, wherein the NH.sub.4OH solution used in step e) is a solution of NH.sub.4OH in ethanol including a NH.sub.4OH concentration ranging from 1 to 2 mol/l. 12. The method according to claim 1 wherein the step of neutralizing the compressed porous layer includes dipping the compressed porous layer in the NH.sub.4OH solution for a period of less than or equal to 30 minutes. 13. The method according to claim 1 wherein the step of neutralizing the compressed porous layer includes dipping the compressed porous layer in the NH.sub.4OH solution for a period ranging from 5 minutes to 20 minutes. 14. The method according to claim 1 wherein the one or more washing steps includes dipping the neutralized compressed porous layer of step e) in one or more baths of sterile water until a washing water with a pH close to 7 is obtained. 15. A method of forming an implant for reinforcing a staple zone including a chitosan based porous layer comprising the following steps: a) preparing a chitosan solution free of any other polymer and including a chitosan concentration ranging from 1.0% to 5% by weight, relative to the total weight of the solution, b) adjusting the pH of the chitosan solution to a pH ranging from 3 to 5, c) pouring the solution into a mold in order to form a layer, d) lyophilizing the layer obtained in c) to obtain a porous layer, e) compressing the porous layer obtained in d) to obtain a compressed porous layer including a density of greater than equal to 0.65 g/cm.sup.3, f) neutralizing the compressed porous layer obtained in e) by using a NH.sub.4OH solution comprising a NH.sub.4OH concentration ranging from 0.6 to 2 mol/l to obtain a neutralized compressed porous layer, and, g) subjecting the neutralized compressed porous layer obtained in f) to one or more washing steps. 16. The method according to claim 15, wherein the chitosan solution prepared in step a) is a solution of chitosan in water having a chitosan concentration ranging from 2% to 3% by weight, relative to a total weight of the solution. 17. The method according to claim 15, wherein the chitosan includes a degree of acetylation ranging from 1% to 10%. 18. The method according to claim 15, wherein the chitosan includes a degree of acetylation ranging from 2% to 3%. 19. The method according to claim 15, wherein the pH is 3.5 by adding acetic acid. 20. The method according to claim 15, wherein the NH.sub.4OH solution used in step e) is a solution of NH.sub.4OH in water or ethanol including a NH.sub.4OH concentration ranging from 1 to 2 mol/l.

Details for Patent 10,363,690

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Merck Sharp & Dohme Corp.	ZOSTAVAX	zoster vaccine live	For Injection	125123	05/25/2006		2032-08-02