Abstract
Freeze-drying is a popular method to stabilize many therapeutic proteins that are not stable enough to meet the long-term stability required for pharmaceutics. In spite of the improved long-term stability, various stresses during the freeze-drying and subsequent storage often induce structural (e.g. denaturation, aggregation) and chemical (e.g., oxidation) changes of the proteins. This review describes how the various excipients (e.g., saccharides, polyols, polymers, surfactants, buffer components) stabilize proteins in each process. Effects of solute miscibility and crystallinity on the stabilizing effect were also discussed.
