Abstract: The present invention relates to a polymer paste and a sustained release composition comprising the paste and a biologically active agent. The polymer paste comprises a biocompatible, biodegradable polymer having an inherent viscosity of about 0.12 dL/g or less and a viscosity reducing agent, wherein the biocompatible, biodegradable polymer is present in the polymer paste in at least 60% by weight and the viscosity of the paste is about 400 cP or less. The sustained release composition comprises a biologically active agent and a polymer paste comprising a biocompatible, biodegradable polymer having an inherent viscosity of about 0.12 dL/g or less and a viscosity reducing agent, wherein the biocompatible, biodegradable polymer is present in the polymer paste in at least 60% by weight and the viscosity of the sustained release composition is about 400 cP or less. In a particular embodiment, the sustained release composition is injectable.

Abstract: Orthopedic mixtures are prepared by mixing starting materials and a process medium in a reactor to form a supercritical fluid slurry. The starting materials include a source of calcium ions and a polymer matrix for the calcium ions. The process medium preferably is carbon dioxide which is supplied to the reactor in a supercritical state or which is heated and pressurized in the reactor to attain a supercritical state. After mixing for a period of time, the slurry either is left in the reactor or is discharged into a receiving vessel. The process medium is separated from the other materials and removed, leaving behind a finely divided product. The finely divided product can be poured into a mold and cured. Thereafter, the cured product can be used as a bone implant or a bone implant can be carved from the cured product. Alternatively, if an ultraviolet light-curable catalyst and a monomer are included in the mixture, the finely divided product can be used as bone filler and cured in situ.

Abstract: Polymer matrices for use in orthopedic, pharmaceutical, and similar mixtures are prepared by mixing two or more polymers and a process medium in a reactor to form a supercritical fluid slurry. The process medium preferably is carbon dioxide which is supplied to the reactor in a supercritical state or which is heated and pressurized in the reactor to attain a supercritical state. After mixing for a period of time, the slurry either is left in the reactor or is discharged into a receiving vessel. The process medium is separated from the polymers and removed, leaving behind finely divided particles.

Abstract: Orthopedic parts are manufactured using supercritical fluid processing techniques in which starting materials and a process medium are mixed in a reactor to form a supercritical fluid slurry. The starting materials include a source of calcium ions and a polymer matrix for the calcium ions. The process medium preferably is carbon dioxide which is supplied to the reactor in a supercritical state or which is heated and pressurized in the reactor to attain a supercritical state. A conduit connects the reactor to a mold that has a cavity of a desired shape for an orthopedic part. A flush valve interconnects the bottom of a reactor and the conduit. When the flush valve is opened, the slurry is directed through the conduit into the mold where solidification occurs very rapidly.