Concentrated protein solutions are widely used in biopharmaceutical research and development. A thorough viscosity analysis of these concentrated protein formulations should include both shear rate and temperature variation. The data can be used for to predict performance at any relevant temperature or to investigate the component interactions and resulting microstructure.
In this application note we combine shear rate and temperature sweeps to thoroughly characterize a single bovine γ-globulin formulation. In addition to discussing the practical benefits related to processing and delivery, we also apply a scaling analysis to estimate the characteristic length scale of the protein aggregates in solution. It is well established that temperature variation will impact the rate of molecular motion or diffusion, but changes in the pair interaction potential of colloidal systems is also possible and can affect the aggregation behavior. The goal of the analysis was to determine whether modest temperature variation produced changes in the protein cluster formation.