(91e) Innovations in Ultrafiltration Technology in Biopharmaceutical Processing

Ultrafiltration (UF) has been extensively used for the concentration and diafiltration of protein solutions. The standard mode of operation for Tangential Flow Filtration (TFF) is batch processing, where the retentate is returned to the feed tank and the permeate stream is directed to drain or a collection tank. As the target concentration of biopharmaceutical antibody solutions approaches levels in excess of 150g/L, difficulties can arise associated with processing and recovering viscous product solutions. Typically, the transmembrane pressure (TMP) is kept constant along with either cross-flow rate or feed side pressure drop (dP=feed pressure minus retentate pressure) control. Experimental data for the concentration of bovine immunoglobulin (IgG) solutions from 15g/L to ~180g/L is presented using both methods of control, while monitoring the change in process flux, feed viscosity, retentate flow rate, and feed side dP as the IgG solution was concentrated. Product recovery strategies using plug flow chase and recirculated buffer flush methods are also presented.