Conventional tangential flow filtration (TFF) has traditionally been limited to separation of solutes that differ by about ten‐fold in size. Wide pore‐size distributions, membrane fouling, and concentration polarization phenomena have commonly been cited as reasons for this limitation. The use of TFF in the biotechnology industry has therefore been restricted to cell‐protein, virus‐protein, and protein‐buffer separations. A multi‐disciplinary team with industrial and academic members was formed to overcome these limitations and enable protein‐protein separations using High Performance TFF (HPTFF) systems. Pore‐size distributions have been improved with the development of new membrane formulation and casting techniques. Membrane fouling has been controlled by operating in the transmembrane pressure‐dependent regime of the filtrate flux curve and by carefully controlling fluid dynamic start‐up conditions. Concentration polarization was exploited to enhance, rather than limit, the resolution of solutes. Concentration polarization has also been controlled by operating a co‐current filtrate stream that maintains transmembrane pressure constant along the length of the TFF module. High yields and purification factors were obtained even with small differences in protein sieving. IgG‐BSA and BSA monomer‐oligomer mixtures have successfully been separated with these systems. HPTFF technology provides a competitive purification tool to complement chromatographic processing of proteins. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 71–82, 1997.

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Tangential flow filtration has traditionally been scaled up by maintaining constant the filtrate volume to membrane surface area ratio, membrane material and pore size, channel height, flow path geometry and retentate and filtrate pressures. Channel width and the number of channels have been increased to provide increased membrane area. Several other parameters, however, have not been maintained constant. A new comprehensive methodology for implementation of linear scale up and scale down of tangential flow filtration processes has been developed. Predictable scale up can only be achieved by maintaining fluid dynamic parameters which are independent of scale. Fluid dynamics are controlled by operating parameters (feed flow rate, retentate pressure, fed batch ratio and temperature), geometry (channel length, height, turbulence promoter and entrance/exit design), materials (membrane, turbulence promoter, and encapsulant compression), and system geometry (flow distribution). Cassette manufacturing procedures and tolerances also play a significant role in achieving scale independent performance. Extensive development work in the aforementioned areas has resulted in the successful implementation of linear scale up of ultrafiltration processes for recovery of human recombinant DNA derived pharmaceuticals. A 400‐fold linear scale up has been achieved without intermediate pilot scale tests. Scale independent performance has a direct impact on process yield, protein quality and product economics and is therefore particularly important in the biotechnology industry. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 737–746, 1997.

There is growing interest within the biopharmaceutical industry to improve manufacturing efficiency through process intensification, with the goal of generating more product in less time with smaller equipment. In monoclonal antibody (mAb) purification, a unit operation that can benefit from intensification is anion exchange (AEX) polishing chromatography. Single‐pass tangential flow filtration (SPTFF) technology offers an opportunity for process intensification by reducing intermediate pool volumes and increasing product concentration without recirculation. This study evaluated the performance of an AEX resin, both in terms of host cell protein (HCP) purification and viral clearance, following concentration of a mAb feed using SPTFF. Results show that preconcentration of AEX feed material improved isotherm conditions for HCP binding, resulting in a fourfold increase in resin mAb loading at the target HCP clearance level. Excellent clearance of minute virus of mouse and xenotropic murine virus was maintained at this higher load level. The increased mAb loading enabled by SPTFF preconcentration effectively reduced AEX column volume and buffer requirements, shrinking the overall size of the polishing step. In addition, the suitability of SPTFF for extended processing time operation was demonstrated, indicating that this approach can be implemented for continuous biomanufacturing. The combination of SPTFF concentration and AEX chromatography for an intensified mAb polishing step which improves both manufacturing flexibility and process productivity is supported.

BACKGROUND Virus inactivation of plasma products is conducted using stainless‐steel vessels. Single‐use technology can offer significant benefits over stainless such as operational flexibility, reduced capital infrastructure costs, and increased efficiency by minimizing the time and validation requirements associated with hardware cleaning. This study qualifies a single‐use bag system for solvent/detergent (S/D) virus inactivation. STUDY DESIGN AND METHODS Human plasma and immunoglobulin test materials were S/D‐treated in Mobius single‐use bags using 1% tri‐n‐butyl phosphate (TnBP) with 1% Triton X‐100 or 1% Tween 80 at 31°C for 4 to 6 hours to evaluate the impact on protein quality. Volatile and nonvolatile organic leachables from low‐density polyethylene film (Pureflex film) used in 1‐L‐scale studies after exposure to S/D in phosphate‐buffered saline were identified compared to controls in glass containers. Virus inactivation studies were performed with xenotropic murine leukemia virus (XMuLV) and bovine viral diarrhea virus (BVDV) to determine the kinetics of virus inactivation, measured using infectivity assays. RESULTS S/D treatment in Mobius bags did not impact the protein content and profile of plasma and immunoglobulin, including proteolytic enzymes and thrombin generation. Cumulative leachable levels after exposure to S/D were 1.5 and 1.85 ppm when using 0.3% TnBP combined with 1% Tween 80 or 1% Triton X‐100, respectively. Efficient inactivation of both XMuLV and BVDV was observed, with differences in the rate of inactivation dependent on both virus and S/D mixture. CONCLUSION Effective S/D virus inactivation in single‐use container technology is achievable. It does not alter plasma proteins and induces minimal release of leachables.