An insulin delivery system from oxidized cellulose.

Cellulose oxidized with periodate (OC) has been shown to be a biocompatible, biodegradable matrix suitable for immobilization and sustained release of drugs. In the present work, insulin was immobilized on the OC-matrix and the release profile in vivo and in vitro was examined. The hormone is bound to the matrix by Schiff's bond formation and is released by hydrolysis of this bond as well by degradation of the OC-matrix. The release can be sustained over longer periods by reducing the Schiff's base with NaBH4. The insulin depots could be conveniently injected as suspensions and are able to maintain glucose levels in diabetized rabbits at normal values over several days.