Subvisible Particulate Matter in Therapeutic Protein Injections

Abstract

Strategies for determining particulate matter in therapeutic protein injections, including extrinsic and intrinsic particles, are reviewed. Special attention is devoted to the advantages and limitations of various methods used for these purposes, each of which enables different particle characteristics to be determined. The source of particles (extrinsic, intrinsic, or inherent) can be understood better and particle-size distribution and other characteristics can be studied and used to differentiate them if methods based on different measurement principles are used. Protein aggregates in drugs have broad particle-size distributions, from oligomers to particles reaching hundreds of microns. The particle properties can be used to assess the risk associated with protein aggregates in the drug and to study their possible formation mechanisms. Such information could be useful during drug development and manufacturing to reduce the particulate matter content.