In biopharmaceutical manufacturing, therapeutic proteins are exposed to various process conditions that may cause physical instability. One of the results of physical instability is aggregate formation, which is of concern for product quality due to potential immunogenicity. Because of this criticality, during process development, it is essential to study, understand and control aggregate-forming process conditions. Here, an investigation was performed on the aggregation of a monoclonal IgG4 antibody exposed to mechanical stress by generating 1) air-liquid interface using an overhead impeller, and 2) gas-liquid interface by bubbling nitrogen into solution. The effects of protein concentration, buffer composition, tip speed, and mixing duration were investigated. Products were characterized with respect to changes in secondary and tertiary structure and the formation of aggregates and particles using several analytical techniques (micro-flow imaging, size-exclusion chromatography, dynamic light scattering, dynamic scanning calorimetry, UV spectroscopy, turbidimetry, capillary gel electrophoresis, circular dichroism, and intrinsic fluorescence). Despite maintaining intact tertiary and secondary structures, the study showed the molecule’s propensity for aggregate formation and different aggregation pathways at various conditions. The understanding of the molecule’s response to the studied process conditions helps to better control product quality during production.

Effect of air-liquid interface in monoclonal antibody aggregate formation

251st National Meeting (2016)

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