Patent ID: 7125967
Filing Date: 2006-10-24
Classification: A61K,C08B

Abstract:
1. A method of making water-soluble chitosan, said method comprising the steps of: contacting water-insoluble chitosan with a basic solution for a first period of time; rinsing the water-insoluble chitosan to remove any residual basic solution; partially acetylating the water-insoluble chitosan in a reaction solution containing a phase transfer agent to form partially acetylated water-soluble chitosan; dissolving the partially acetylated water-soluble chitosan in an aqueous solution containing a surfactant; adjusting a pH of the aqueous solution to a pH of at least 7.0; adding a water-miscible solvent into the aqueous solution having a pH of at least 7.0; further adjusting the pH of the aqueous solution to a pH of at least 8.0 to cause precipitation of water-soluble chitosan having low endotoxin content; separating the water-soluble chitosan having an endotoxin content of less than about 100 equivalent units per gram of dry water soluble chitosan from the aqueous solution; and washing the water-soluble chitosan having low endotoxin content with the water-miscible solvent.