The bioprocessing industry is interested in Next Generation Processes with higher flexibility, lower costs, and higher product quality. Single-pass tangential flow filtration (SPTFF) can be used to intensify manufacturing processes to meet these goals. Here, SPTFF preconcentration is used to intensify the anion exchange (AEX) polishing step in monoclonal antibody (mAb) processing for improved impurity removal and column productivity. This intensified polishing approach can be linked with upstream steps for a more continuous process which eliminates tankage and hold time, and enables the use of smaller polishing columns to improve product quality at higher throughputs.
It is common in mAb downstream purification processes to use a flow through AEX resin as a final impurity adsorption step. This step uses positively charged quaternary ammonium groups to adsorb negatively charged host cell protein (HCP) and virus impurities while allowing the positively charged therapeutic mAb product to flow through unbound. In many cases, the feed material is pre-diluted to reduce the solution conductivity below 10 mS/cm for optimal impurity adsorption, and typical mass loadings for AEX resin polishing are 100 – 250 g mAb/L resin. As a result, the conventional polishing approach requires relatively large columns with long process times.