Understanding Adsorption Behavior of Polysorbate-20 to Sterile Filters in Antibody Drug Substance Final Filtration Process

Surfactant is commonly used in the antibody drug substance manufacturing process as a stabilizer. Polysorbate-20 (PS-20) is one of the most commonly used surfactants to mitigate protein aggregation in the final drug substances formulation. It has been observed that polysorbate can be adsorbed by sterile filters during the final filtration process of drug substance, which poses risk of uneven distribution and potentially reduced PS-20 concentration in final products. In this study, we evaluated the PS-20 adsorption behavior by commonly used sterile filters. The study focused on evaluating the adsorption by the sterilizing-grade microfiltration membranes via a customized filtration set-up. The effect of membrane properties, including the membrane materials, modification, and layer configuration were studied. In addition, the PS-20 adsorption amount by each type of membranes was determined quantitatively and showed good agreement with the adsorption kinetics results. Finally, the selection of sterile filters is discussed for ensuring accurate PS-20 content in the final drug substance.