| abstract |
PURPOSE: To obtain the title particles excellent in safety, biocompatibility and swellability and useful as a carrier for physiologically active substances, by reacting specified chitosan particles with an aromatic compound and crosslinking the product with an organic diisocyanate. n CONSTITUTION: Chitosan particles (A) are obtained by coagulating a 3W6% acidic aqueous chitosan solution obtained by dissolving chitosan of an average MW of 10,000W230,000 in an aqueous acid solution (e.g., aqueous acetic acid solution) by feeding it under a pressure to a basic aqueous solution (e.g., aqueous NaOH solution) optionally containing a polar alcohol. Component A is reacted with 0.1W0.5mol, per mol of the glucosamine residues of component A, of an aromatic compound (B) (e.g., cyanuric chloride) in a polar solvent (e.g., dimethylformamide), and the product is crosslinked in a polar solvent containing 5W10% organic diisocyanate compound (C) (e.g., hexamethylene diisocyanate) to obtain the title particles having an apparent density of 0.015W0.030g/ml and a particle diameter of 0.10W0.35mm. n COPYRIGHT: (C)1988,JPO&Japio |