Recent advances and applications of capillary electrophoresis-sodium dodecyl sulfate for characterization and fragment identification of monoclonal antibodies and their derivatives

Capillary electrophoresis-sodium dodecyl sulfate (CE-SDS), a high-resolution and high-sensitivity analytical technique, is an essential tool for analyzing the critical quality attributes (CQAs) of monoclonal antibodies (mAbs) and their derivatives, including antibody-drug conjugates (ADCs) and bispecific antibodies (bsAbs). This study systematically reviews the applications of CE-SDS in analyzing the purity and fragments of mAbs, characterizing positional isomers of ADCs, and identifying mismatch impurities in bsAbs. Focusing on the core technical challenge that CE-SDS cannot be directly coupled with mass spectrometry (MS) for fragment structure identification, the study summarizes technical solutions based on indirect identification approaches and offline/online coupling strategies with Capillary Zone Electrophoresis-Mass Spectrometry (CZE-MS). In addition, from a regulatory science perspective, this study details the key considerations for method validation, establishment of quality standards, and preparation of regulatory submissions for CE-SDS. This study aims to provide a systematic reference for the development and quality control of related biopharmaceuticals, highlighting future development directions, including high-throughput analysis, coupling techniques, and degradation prediction.