Single pass tangential flow filtration: Critical operational variables, fouling, and main current applications

The biopharmaceutical industry has an ongoing interest in improving manufacturing efficiency and productivity while at the same time reducing manufacturing costs by developing intensified, linked and continuous processes. In recent years, upstream productivity of bioprocesses has improved significantly resulting in increased volumes and increased titers, which have put downstream processes under enormous pressure. Single Pass Tangential Flow Filtration (SPTFF) is a technology that offers an opportunity to reduce process volumes efficiently through inline concentration in one single pass through a series of membranes without the need for retentate recirculation. This technology links upstream and downstream operations and has the capability to ensure continuous production. This review seeks to investigate both early papers on SPTFF and recent developments in the field, including single-use SPTFF and 3D printed membrane modules. To our knowledge, this review is the first to address SPTFF and is aimed at gathering all relevant information about the topic, with a special focus on application in bioprocessing from which this technology has evolved. Due to a growing need for intensified processes, interest in SPTFF within the biopharmaceutical industry is increasing, hence the importance of gathering all relevant information on the topic in this review. The review starts with a thorough comparison between normal tangential flow filtration (TFF) and SPTFF, including principles, configuration, and typical features of these technologies. Also addressed are the design equations and how to tackle fouling. The review ends by providing relevant information about the main applications of SPTFF in bioprocessing as well as future perspectives on the operation. The review mainly deals with application in the biopharmaceutical industry but includes examples from the food industry and wastewater treatment.