The present invention is directed to a material which can be used to deliver a drug, such as an antibiotic, into a diseased tissue pocket, such as a periodontal pocket. The material is preferably a bioerodible oligomer or polymer. The oligomer or polymer containing the drug is heated and is then delivered, preferably by injection, into the tissue pocket at a physiologically compatible elevated temperature. Once the bioerodible material is injected into the pocket, the material cools to the body temperature of the pocket. As it cools, the material hardens and remains in place in the tissue pocket. The hardened material bioerodes in the pocket and releases the drug over a period of several days.