BIORESORBABLE POLYMER MICROSPHERES FREE FROM SURFACE ACTIVE AGENTS, THEIR PREPARATION AND APPLICATION AS DRUG

摘要

Microspheres consisting of a polymer matrix and optionally at least one active substance encapsulated in said polymer matrix made from at least one hydroxyacid polymer or copolymer. Said microspheres are characterized by the absence of surface active agents and of constituents other than the optionally present active substance and the polymer constituents. The microspheres can be obtained by using, as the polymer matrix, a poly(hydroxyacid) of high molecular weight exceeding 20,000 and a poly(hydroxyacid) having a molecular weight of less than 5,000. The incorporation of said microspheres as drugs is beneficial in preventing the induced toxicity associated with microspheres of the past caused by the residual surface active agent.