Abstract: Pharmaceutical compositions that enable the release of a physiologically active substance over a prolonged period of time following administration to a patient are described. The pharmaceutical compositions are provided by encapsulation of a physiologically active substance into a matrix comprising biodegradable polymers and lipids. The rate of release of the physiologically active substance from the pharmaceutical composition is controlled by varying the ratio of the polymer to the lipid. The compositions can be stored in an aqueous suspension or as a solid dosage form. The physiologically active substances include small molecules, peptides, proteins, nucleic acids and vaccines. The biodegradable polymers include homopolymers, or random or block copolymers. The lipids include phospholipids, cholesterol and glycerides.

Abstract: Pharmaceutical compositions that enable the release of a physiologically active substance over a prolonged period of time following administration to a patient are described. The pharmaceutical compositions are provided by encapsulation of a physiologically active substance into a matrix comprising biodegradable polymers and lipids. The rate of release of the physiologically active substance from the pharmaceutical composition is controlled by varying the ratio of the polymer to the lipid. The compositions can be stored in an aqueous suspension or as a solid dosage form. The physiologically active substances include small molecules, peptides, proteins, nucleic acids and vaccines. The biodegradable polymers include homopolymers, or random or block copolymers. The lipids include phospholipids, cholesterol and glycerides.

Abstract: Disclosed is a method for making liposomes, for example multivesicular liposomes (MVLs), containing one or more biologically active agents, wherein the loading of the active agents into the liposomes is modulated by adjusting the osmolarity of the aqueous component into which the agents are dissolved prior to encapsulation. To increase the loading of the active agent, the osmolarity of the aqueous component is reduced, and to decrease the loading of the active agent, the osmolarity of the aqueous component is increased. In the making of MVLs, the process involves dissolving the active agent and an optional osmotic excipient in a first aqueous component encapsulated within the liposomes. For any given concentration of drug, the osmolarity of the first aqueous component can be adjusted by increasing or decreasing the concentration or molecular weight of the osmotic excipients used therein.