Non-specific binding and saturation of Polysorbate-20 with aseptic filter membranes for drug substance and drug product during mAb production

An issue identified during filtration of mAb drug substance is Polysorbate-20 absorption by polyethersulfone filter membranes. Experiments determined that both polyvinylidene fluoride filter membranes and polyethersulfone filter membranes bind Polysorbate-20. Saturation point, bound surfactant amount per square cm of membrane, and non-specific binding mechanisms are described in this report. An appropriate approach for preventing Polysorbate-20 loss in drug substance and drug product is presented.