Journal of Chromatography & Separation Techniques
Open Access

Abstract

Analysis of Rituximab, A Therapeutic Monoclonal Antibody by Capillary Zone Electrophoresis

Andrasi M, Gyemant G and Gaspar A

This paper focuses on the applicability of capillary zone electrophoresis (CZE) using uncoated fused silica capillaries for the determination of heterogeneity of rituximab (MabThera, Roche) and for the study of its solution and thermal stability. The best resolution for the charge variants of the main component was obtained with a buffer electrolyte containing 800 mM 6-amino caproic acid, 2 mM triethylene tetramine and 0.05% hydroxypropyl methylcellulose at pH = 5.2. It was found that the pH and the components of the buffer used for the electrophoretic separation and for the dilution of the sample prior to the analysis are important to the stability of the rituximab. We demonstrated the rituximab is stable in the pharmaceutical product MabThera due to the stabilizing additives, but the dilution of the MabThera caused a slow formation of acidic variants, while the amount of the basic variants did not change. After incubation of the diluted rituximab at higher temperature several charge variants could be determined by CZE.