Advances in Chromatography for Charge Variant Profiling of Biopharmaceuticals
Biotherapeutic proteins, such as monoclonal antibodies (mAbs), are heterogeneous and exist as variant mixtures of structurally similar molecules. The heterogeneity of monoclonal antibodies is revealed by charge-sensitive methods, such as ion exchange chromatography (IEX). Changes in charge profile can significantly impact the structure, stability, binding affinity, and efficacy of the biotherapeutic drug. It is therefore necessary to understand the profile of the drug so that variants are identified and controlled. This article describes advances in ion exchange column chemistries, elution buffers, and ultrahigh-pressure liquid chromatography (UHPLC) instruments to meet the needs for modern, robust analysis of charge variants in monoclonal antibodies and therapeutic proteins.