High Resolution Separation of Charge Variant Profiles of Monoclonal Antibodies: Rituximab Innovator and Biosimilar

摘要

This article describes the high-resolution separation of charge variants of innovator and biosimilar rituximab using a Bio-inert Quaternary LC, and OpenLAB ChemStation software. A Bio MAb, 4.6 x 250 mm, 5 urn PEEK ion-exchange column was used to obtain a separation. The column features a unique resin designed for the charge-based separation of monoclonal antibodies (mAbs). The optimised salt gradient revealed differences in acidic and basic charge variant profiles of innovator and biosimilar rituximab. Precision of retention time, peak height, and peak area of the charged isoforms were well within the acceptable range. C-terminal digestion by carboxypeptidase B (CPB) revealed the major lysine variant peaks in biosimilar rituximab.