Exploring Factors That Influence Charge Variant Analysis of mAbs with Shim-pack Bio IEX Columns using Salt Gradient Elution

Introduction

Protein-based therapeutic drugs including monoclonal antibodies (mAbs) have shown to be effective against a variety of diseases. It is critical to characterize and monitor the impurities and variations of the products to ensure the efficacy and safety. Post-translational modifications such as deamidation, glycosylation, oxidation, and C-terminal lysine cleavage can lead to charge variations. These charge variants are usually characterized and quantified using ion-exchange chromatography (IEX). IEX separates the biomolecules according to their net charge, which is dependent on pH. Cation-exchange chromatography (CEX) with cation-exchange ligands is commonly used to characterize mAbs with basic isoelectric point (pl >7). The acidic variants are eluted before the main peak while the basic variants eluted after. The elution can be performed using salt or ph gradient. In this study, we describe a charge variant analysis of Trastuzumab using salt gradient with Shimadzu strong cation-exchange column, Shim-pack Bio IEX SP-NP. The separation efficiency under different gradient slopes, gradient times and flow rates are discussed.

June 9, 2020 GMT