There is growing interest in the development of fully integrated and continuous biomanufacturing processes for the production of monoclonal antibody products. A recent study has demonstrated the feasibility of using a two‐stage countercurrent diafiltration (DF) process for continuous product formulation, but this system did not provide sufficient levels of buffer exchange for most applications. The objective of this study was to design and test a three‐stage countercurrent DF system that could achieve at least 99.9% buffer exchange over 24 hr of continuous operation. Experimental data were obtained using concentrated solutions of human immunoglobulin G as a model protein, with the extent of vitamin B12 removal used to track the extent of DF. Pall Cadence™ inline concentrators with Delta 30 kD regenerated cellulose membranes were used in the three stages to achieve high conversion in a single pass. The three‐stage system showed stable operation with >99.9% vitamin B12 removal and a minimal increase in pressure over the full 24 hr. Modules were effectively cleaned using sodium hydroxide, with nearly complete recovery of water permeability. A simple economic analysis was presented that accounts for the trade‐offs between quantity of buffer used and membrane costs for this type of countercurrent staged DF process. The results provide important insights to the design and operation of a continuous process for antibody formulation.

Buffer exchange, desalting, and formulation of high‐value biotherapeutics are currently performed using batch diafiltration (DF); however, this type of tangential flow filtration process may be difficult to implement as part of a fully continuous biomanufacturing process. The objective of this study was to explore the potential of using countercurrent dialysis for continuous protein formulation and buffer exchange. Experiments were performed using concentrated solutions of immunoglobuin G (IgG) with commercially available hollow fiber dialyzers having 1.5 and 1.8 m2 membrane surface area. More than 99.9% buffer exchange was obtained over a range of conditions, as determined from the removal of a model impurity (vitamin B12). The dialyzers were able to process more than 0.5 kg of IgG per day in an easily scalable low‐cost process. In addition, buffer requirements were less than 0.02 L of buffer per gram IgG, which is several times less than that used in current batch DF processes. These results clearly demonstrate the potential of using low‐cost hollow fiber dialyzers for buffer exchange and product formulation in continuous bioprocessing. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2763, 2019.

No abstract

No abstract

Several models have been developed to describe the shifts in pH and excipient concentrations seen during diafiltration of monoclonal antibody (mAb) products accounting for both Donnan equilibrium and electroneutrality constraints. However, these models have assumed that the mAb charge is either constant or only a