Degradable haemostat composition

Abstract

In one aspect, the present invention includes a haemostat composition that includes a chitosan, chitosan salt or chitosan derivative, and a physiologically acceptable acid, which is present in the amount of 45-70% by weight of the haemostat composition. The haemostat composition is able to safely gradually and fully degrade in a human or animal body within about 30 days and so can be utilised by physicians to stem a flow of blood and promote healing both after as well as during surgical procedures.

1 . A haemostat composition comprising:
 a chitosan, chitosan salt or chitosan derivative; and   a physiologically acceptable acid, which is present in the amount of 45-70% by weight of the haemostat composition;   wherein the haemostat composition is in a non-fibrous form, and is able to fully degrade in a human or animal body within about 30 days.   
     
     
         2 . A haemostat composition according to  claim 1 , wherein the haemostat composition is in the form of granules, powder, a sheet, a foam, a freeze dried foam, a compressed foam, a film, a perforated film, beads, a gel, hydrogel sheets and amorphous hydrogel, or a laminate, or a combination of any two or more thereof. 
     
     
         3 . A haemostat composition according to  claim 1 , wherein the haemostat composition is still present in the human or animal body after about 24 hours. 
     
     
         4 . A haemostat composition according to  claim 3 , wherein complete degradation of the haemostat composition occurs after more than about 4 days but less than about 30 days. 
     
     
         5 . A haemostat composition according to  claim 4 , wherein complete degradation of the haemostat composition occurs after more than about 7 days but less than about 30 days. 
     
     
         6 . A haemostat composition according to  claim 1 , further comprising a physiologically acceptable acid. 
     
     
         7 - 9 . (canceled) 
     
     
         10 . A haemostat composition according to  claim 6 , wherein the physiologically acceptable acid comprises an organic acid and/or an inorganic acid. 
     
     
         11 . A haemostat composition according to  claim 10 , wherein the organic acid comprises a carboxylic acid. 
     
     
         12 . A haemostat composition according to  claim 11 , wherein the carboxylic acid is selected from formic acid, acetic acid, ascorbic acid, halogen acetic acids, propanoic acid, propenoic acid, lactic acid, succinic acid, acrylic acid, glyoxylic acid, pyruvic acid or a hydroxy propionic/butanoic acid, and combinations of any two or more thereof. 
     
     
         13 . A haemostat composition according to  claim 12 , wherein the carboxylic acid is selected from lactic, acetic and succinic acids, and combinations of any two or more thereof. 
     
     
         14 . A haemostat composition according to  claim 13 , wherein the carboxylic acid is lactic acid. 
     
     
         15 . A haemostat composition according to  claim 10 , wherein the inorganic acid comprises one or more of hydrochloric acid and/or sulphuric acid. 
     
     
         16 . A haemostat composition according to  claim 1 , wherein the haemostat composition comprises a chitosan salt. 
     
     
         17 . A haemostat composition according to  claim 16 , wherein the chitosan salt comprises one or more salts selected from chitosan acetate, chitosan lactate, chitosan succinate, chitosan malate, chitosan acrylate, chitosan formate, chitosan ascorbate, chitosan fluoroacetate, chitosan chloroacetate, chitosan propanoate, chitosan glyoxylate, chitosan pyruvate, chitosan sulphate, or chitosan chloride. 
     
     
         18 . A haemostat composition according to  claim 17 , wherein the chitosan salt comprises chitosan lactate. 
     
     
         19 . A haemostat composition according to  claim 1 , wherein the haemostat composition comprises a chitosan salt, the physiologically acceptable acid is a carboxylic acid and is present in an amount of between about 45-60% by weight of the haemostat composition, and the haemostat composition is in the form of granules or powder. 
     
     
         20 . A haemostat composition according to  claim 1 , wherein the haemostat composition is made without subjecting the composition to any heat treatment after the composition has been dried. 
     
     
         21 . A haemostat composition according to  claim 1 , wherein the molecular weight of the chitosan used for the preparation of the haemostat composition is less than about 500,000. 
     
     
         22 . A haemostat composition according to  claim 1 , wherein the viscosity of the chitosan used for the preparation of the haemostat composition is from about 40 to about 200 cps when measured at 20° C. 
     
     
         23 . A haemostat composition according to  claim 1 , wherein the haemostat composition is sterilized. 
     
     
         24 . A haemostat composition according to  claim 1 , further comprising one or more components selected from pharmaceutical agents; wetting agents; colouring agents; processing aids; bulking agents; absorbent polymers; antimicrobial agents; growth factors; cytokines; agents which absorb agents which delay healing; calcium; vitamin K; fibrinogen; thrombin; factor VII; factor VIII; clays; oxidised regenerated cellulose; gelatine; and/or collagen. 
     
     
         25 . A method of manufacturing a haemostat composition according to  claim 1 . 
     
     
         26 . A method according to  claim 25 , comprising coating the chitosan, chitosan salt or chitosan derivative with a physiologically acceptable acid. 
     
     
         27 . A method according to  claim 25 , further comprising the step of washing the chitosan, chitosan salt or chitosan derivative to reduce the presence of endotoxins prior to the coating step, the washing comprising contacting the chitosan, chitosan salt or chitosan derivative with an alkali solution to form a mixture, and then leaving the mixture for a period of time before drying it. 
     
     
         28 . A method of absorbing fluid discharged from a physiological target site, or of stemming a flow of a fluid discharged from a physiological target site, comprising applying to the physiological target site a haemostat composition according to  claim 1 . 
     
     
         29 . Use of a haemostat composition according to  claim 1  in absorbing fluid discharged from a physiological target, or in stemming a flow of a fluid discharged from a physiological target site. 
     
     
         30 . A method according to  claim 27 , wherein the haemostat composition comprises a chitosan, chitosan salt or chitosan derivative, wherein the haemostat composition is in a non-fibrous form, and is able to fully degrade in a human or animal body within about 30 days; and wherein the haemostat composition is retained within a human or animal body after a medical procedure. 
     
     
         31 . (canceled)