Solutions and films of glycated chitosan

Abstract

Preparations containing glycated chitosan in a physiologically compatible carrier are described. Viscoelastic preparations comprise 1.0-12.0 percent by weight of glycated chitosan in an aqueous solution while lower viscosity solutions possess 0.1-0.5 percent by weight glycated chitosan. The otherwise free amino groups of the chitosan polymer are preferably 30-90% glycated and possess an average molecular weight of between 100,000 and 2,000,000 Daltons, and, most preferably between 100,000 and 1,000,000 Daltons.

1 . A viscoelastic preparation comprising greater than 1 percent by weight of a glycated chitosan polymer dispersed in an aqueous solution, said glycated chitosan polymer having a molecular weight of greater than 100,000 Daltons, said aqueous solution having a viscosity greater than 10,000 centistokes measured at 25° and a pH in the range of 5.5 to 7.5.  
     
     
         2 . The viscoelastic preparation according to  claim 1  wherein said aqueous solution possesses a pH between 6.3 and 7.  
     
     
         3 . The viscoelastic preparation according to  claim 1  wherein said aqueous solution comprises a buffered physiological saline solution of said glycated chitosan.  
     
     
         4 . The viscoelastic preparation according to  claim 1  wherein said glycated chitosan polymer possesses between 30-90% glycation of its otherwise free amino groups.  
     
     
         5 . The viscoelastic preparation according to  claim 4  wherein said glycated chitosan polymer possesses about 60% glycation of its otherwise free amino groups.  
     
     
         6 . The viscoelastic preparation according to  claim 1  wherein said glycated chitosan polymer has a molecular weight between 100,000 and 2,000,000 Daltons.  
     
     
         7 . The viscoelastic preparation according to  claim 1  comprising about nine percent by weight of said glycated chitosan polymer dispersed in said aqueous solution, wherein said glycated chitosan polymer possesses about 60% glycation of its otherwise free amino groups, and said aqueous solution having a viscosity of about 77,000 centistokes.  
     
     
         8 . The viscoelastic preparation according to  claim 1  additionally containing one or more different viscoelastic materials miscible in said aqueous solution.  
     
     
         9 . The viscoelastic preparation according to  claim 8  wherein said different viscoelastic material is selected from the group consisting of hyaluronic acid, chondroitin sulfate and carboxymethylcellulose.  
     
     
         10 . The viscoelastic preparation according to  claim 1  wherein said glycated chitosan polymer comprises a monosaccharide bonded to said otherwise free amino groups.  
     
     
         11 . The viscoelastic preparation according to  claim 11  wherein said monosaccharide comprises galactose.  
     
     
         12 . The viscoelastic preparation according to  claim 1  wherein said glycated chitosan polymer is in the form of a Schiff base, an Amadori product or mixtures thereof.  
     
     
         13 . The viscoelastic preparation according to  claim 1  wherein said glycated chitosan polymer is in the form of a reduced Schiff base, a reduced Amadori product or mixtures thereof.  
     
     
         14 . The viscoelastic preparation according to  claim 1  wherein said glycated chitosan polymer possesses a number of chemically modified monosaccharide or oligosaccharide substituents.  
     
     
         15 . An eye drop preparation comprising less than 1 percent by weight of a glycated chitosan polymer dispersed in an aqueous solution, said aqueous solution having a viscosity of between 10-100 centistokes measured at 25°.  
     
     
         16 . A dried film comprising glycated chitosan.