(191bn) Polysorbate 80 Disposition Following Tangential Flow Filtration

Tangential Flow Filtration (TFF) is known to cause partial unfolding and aggregation of proteins, leading to poor product quality and potential patient safety concerns. While downstream controls are typically in-place, the use of a surfactant such as Polysorbate 80 (PS80) can prevent unfolding and aggregation by protecting sensitive proteins from stress during TFF and subsequent operations. However, PS80 has not been commonly used upstream of TFF because it is challenging to predict its disposition following TFF operations. The two following items highlight sources of this challenge: (1) PS80 is difficult to consistently filter because it can be present as a monomer, micelle, or larger non-spherical micelle. (2) PS80 distribution during and after TFF may be affected by protein-PS80 interactions, which would inhibit separation via TFF.

By better understanding the mechanisms effecting PS80 disposition after TFF, new insight can be gained as to how PS80 could be best used upstream of TFF to increase drug product quality while maintaining predictable output stream composition. For this study, several experiments were performed to evaluate the effect of key filtration and TFF parameters on PS80 disposition. One such experiment included centrifugal filtration or depth flow filtration to assist with the screening of parameters non-specific to TFF such as PS80 concentration, protein presence, and membrane molecular weight cut off (MWCO). These experiments showed that the main contributions to PS80 retention is protein presence and protein concentration. The potential presence of larger non-spherical micelles due to high PS80 concentration does not inhibit PS80 removal. This presentation will review different approaches used to study which factors impact PS80 retention and removal and how final PS80 compositions may be predicted when it is introduced upstream of TFF.