ACID ANHYDRIDE AS SPEED CONTROLLING AGENT FOR INVADING POLYMER CONTAINING USEFUL SUBSTANCE DISPERSED IN POLYMER MOTHER BODY OR POLYMER MOTHER BODY SURROUNDING USEFUL SUBSTANCE

摘要

The invention relates to the use of an acid anhydride incorporated as a latentiated catalyst in poly(ortho ester) and other polymers such that upon exposure to aqueous environments the acid anhydride generates the corresponding acid which catalyzes the matrix erosion. The releasing rate of a loaded drug substance incorporated into or surrounded by the poly(ortho ester) or other polymers can be controlled in that the drug is released as the poly(ortho ester)s or other polymer is eroded by action of the acid anhydride incorporated therein.