Recent progresses of understanding the viscosity of concentrated protein solutions

Viscosity control for concentrated protein solutions is very important for the manufacturability and drug delivery routes of many protein therapeutics of the pharmaceutical industry. Even though there are successful applications of colloidal theories to calculate or predict the viscosity of globular proteins with electrostatic repulsions, understanding concentrated protein solutions remains an open challenge for colloidal science. This is especially true when proteins have complicated interaction potentials and non-spherical shapes, such as monoclonal antibody proteins. This paper provides a brief review of the recent experimental and theoretical progress in understanding the viscosity of concentrated protein solutions with a focus on the experimental results.