There is a growing interest across the industry in developing technologies for subcutaneous delivery of high dose protein therapeutics. High concentration protein solutions are limited by viscosity and stability; both phenomena are driven by protein-protein interactions in solution. Three primary approaches have emerged to overcome the technical challenges associated with high dose delivery: high volume delivery, viscosity reducing excipients, and high concentration suspensions. While high concentration suspensions represent the furthest departure from traditional parenteral formulations for therapeutic proteins, this approach has the potential to address both the syringability and stability challenges as well as to provide a broadly applicable technology platform.

Learning Objectives:

- Describe the key design considerations for high concentration protein suspensions capable of delivering high dose protein therapeutics subcutaneously.

- Describe the impact of physical properties of microparticles on suspension behavior.

- Understand the design space in which spray drying can be leveraged to engineer particles to optimize suspension performance.