Monoclonal antibody molecules frequently undergo chemical modification such as deamination and oxidation, resulting in chemical variants. When such modifications result in changes in isoelectric point, these variants are also referred to as charge variants. Charge variants frequently show altered efficacy, pharmacokinetic properties, and physical properties. However, the difference in charge being subtle, separation based on this property is quite challenging. Charge variants are generally separated at a preparative scale using ion-exchange column chromatography. In large-scale preparative columns, the diameter is frequently comparable, or even larger than the bed height. Dispersion in peripherals, non-uniform packing and severe flow maldistribution in the headers, and consequent poor separation efficiency is a serious problem with such columns. Non-uniformity of flow within preparative columns result in peak broadening and poor resolution, which decreases recovery, increases operating time and buffer usage, and necessitates subsequent concentration steps. Researchers have tried to address the problem of column maldistribution by modification of the headers, better column packing, and by developing parallel flow, curtain flow, and radial flow columns. In our group, we have proposed a radically different approach for reducing flow maldistribution through the use of box-shaped or cuboid packed-bed devices. In this study, a cuboid packed-bed device packed with Capto S ImpAct resin was used to separate acidic and basic variants of monoclonal antibody hIgG1-CD4. The cuboid packed-bed device showed significantly superior separation attributes than its equivalent column. Our process was optimized to obtain high-resolution separation of monoclonal antibody charge variants.

High-resolution separation of monoclonal antibody charge variants using a cuboid packed-bed device

255th National Meeting (2018)

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