Abstract: Homopolymers and copolymers of lactones are prepared by ring-opening polymerization of a mixture of lactones which includes a monolactone, such as .epsilon.-caprolactone, and a dilactone, such as bis-2,2-(.epsilon.-caprolacton-4-yl)propane, which is capable of forming crosslinks. The resulting polymers range from tough and partially crystalline to amorphous, elastomeric materials, depending on the monomer composition and proportions. Additionally, these polymers may be designed to achieve different degrees of permeability and rates of biodegradation. As such, they are useful for the controlled delivery of medicinal agents and as surgical aids and temporary artificial biomaterials such as skin substitutes and burn dressings.

Abstract: Compositions containing either poly(.epsilon.-caprolactone) or copolymers of .epsilon.-caprolactone with other lactones, together with a drug, when subdermally implanted in the body, provide a slow sustained release of the drug. The polymers may be designed to biodegrade during or subsequent to the depletion of the drug.