Cross-linked polysaccharides

Abstract

A product having application in the medical, pharmaceutical and dermo-cosmetic fields comprising a cross-linked polysaccharide in which cross-linkage exists only through amide bonds between carboxy groups of the polysaccharide and amino groupss of a polyamine.

1 . A product having application in the medical, pharmaceutical and dermo-cosmetic fields comprising a cross-linked polysaccharide in which cross-linkage exists only through amide bonds between carboxy groups of the polysaccharide and amino groupss of a polyamine.  
     
     
         2 . A product according to  claim 1  in which it is complexed with zinc, copper or iron ions.  
     
     
         3 . A product according to  claim 1  in which the it sulfated with a pyridine-sulfur trioxide complex.  
     
     
         4 . A pharmaceutical composition in which the principal ingredient is a product according to  claim 1 .  
     
     
         5 . A product having application in the medical, pharmaceutical and dermo-cosmetic fields comprising a cross-linked polysaccharide in which cross-linking occurs only through amide bonds between carboxy groups of the polysaccharide and amino groups of a polyamine in which the polysaccharide is selected from the group consisting of hyaluronic acids, carboxymethyldextran, carboxymethylcellulose, carboxymethylstarch, alginic acids, cellulose acid, N-carboxymethyl or butyl glucans or chitosans, heparins with different molecular weights, optionally desulfated and succinylated, dermatan sulfates, chodroitin sulfates and heparin sulfates obtained by (a) reacting the carboxy groups of a polysaccharide in an aqueous aprotic solvent using a suitable carboxy activating agent, (b) reacting the carboxy activated polysaccharide with a polyamine selected from the group having the formula R 1 —NH-A-NH—R 2  herein R 1  and R 2 , which may be the same or different, are hydrogen, C 1 -C 6  alkyl, phenyl, or benzyl groups; A is a C 2 -C 10  alkylene chain; a polyoxylene chain of the formula [(CH 2 ) n ] m  wherein n is 2 or 3 and m is an interger from 2 to 10, a C 5 -C 7  cycloalkyl group or an aryl or heterocyclic group and (c) recovering the resultant cross-linked polsaccharide.  
     
     
         6 . A product according to  claim 4  in which it is complexed with zinc, copper or iron ions.  
     
     
         7 . A product according to  claim 4  in which it is sulfated with a pyridine-sulfur trioxide complex.