Chemical stability of proteins in injectable drug delivery systems

BIOT 133

Franklin Okumu, Biopharmaceutical R&D, DURECT Corporation, 2 Results Way, Cupertino, CA 95014
Multiple formulation approaches have been evaluated to integrate proteins with injectable drug delivery systems. In summary these approaches fall into three major categories. Formulations of proteins for use with hydrated systems (hydrogels, liposomes, other), dehydrated particulate systems (microspheres, nanospheres, other) and injectable liquids (polymer and non polymer based). In all cases it is critical for the formulator to preserve the proteins chemical, physical and structural integrity during the manufacturing process. In most cases the only way to achieve sufficient stability of the therapeutic protein is the removal of water. This is normally accomplished by dehydration. In general this process slows down or eliminates chemical and physical changes that could reduce potency or lead to immunogenicity. However chemical and physical changes still occur and these changes must be monitored to assess impact of formulation variables on the chemical stability of proteins. The impact of formulation composition, manufacturing and storage on chemical stability of proteins in injectable drug delivery systems will be discussed.