(244f) Buffer Effects on Viral Filtration of Mab Solutions with Hollow Fiber Membranes

Current large-scale monoclonal antibody (MAb) purification processes typically include a viral filtration (VF) step after primary recovery and chromatography, but prior to final formulation. The ability to perform VF after final formulation could have significant economic (i.e. less membrane area due to lower filtrate volume), as well as regulatory (i.e. reduced risk of adventitious viral contamination) advantages. This scenario would require filtration of highly-concentrated feed streams (20-50 g/L) in a variety of buffer matrices. In previous work, we have demonstrated efficient filtration of MAb solutions up to 20 g/L, with hollow fiber membranes, in a system with two primary buffering species. Here, we discuss experimentation with different buffer conditions (i.e. conductivity, pH, multiple components) to allow for filtration of MAb solutions containing product at > 20 g/L. Results from dynamic light scattering (DLS) measurements will be employed to evaluate the impact of MAb-specific self-association behavior that significantly affects VF performance. Along with DLS data, we will use an experimental method outlined by Syedain et al (Biotechnol. Prog. 2006, 22, 1163) to study the localized concentration profile of several MAbs on the surface of hollow fiber membranes, as well as possible MAb-membrane interactions. The data from these different studies could eventually be used to create a theoretical/predictive model for VF operation.