Advancing Charge Variant Analysis With pH-Gradient Ion-Exchange Chromatography: Optimizing Monoclonal Antibody Characterization Using the High-pH Kit for the Alliance™ iS Bio HPLC System
Charge variant analysis is a critical component in the characterization of monoclonal antibody (mAb) therapeutics, ensuring product consistency, safety, and efficacy. This study employs a pH-gradient ion-exchange chromatography method to evaluate charge heterogeneity using the Alliance iS Bio HPLC System equipped with a high-pH kit. Two high-pH kits were assessed for suitability, demonstrating exceptional repeatability and reproducibility when analyzing a Waters™ mAb Charge Variant Standard. Peak area and retention time %RSDs consistently met acceptance criteria, confirming robust performance.
Additionally, the method was applied to infliximab charge variant analysis, revealing precise quantification of lysine charge variants. The high-pH kit was installed on the Alliance iS Bio HPLC System and coupled with both the BioResolve™ SCX mAb Column and BioResolve CX pH Concentrates for a pH gradient ion-exchange separation. Testing of the mAb sample showed good separation of the lysine variants. Furthermore, the high-pH kits produced reproducible results, with relative peak area variations within 3–5%, highlighting method reliability. Minor charge variants were consistently detected, underscoring the analytical sensitivity of the approach. Importantly, despite operating under extreme pH conditions, system performance remained stable over time, mitigating concerns of instrument degradation.
The results validate the Alliance iS Bio HPLC System with high-pH enhancements as a powerful tool for routine charge variant monitoring with a pH gradient in biopharmaceutical development. The study establishes a robust, sensitive, and reproducible method, ensuring confidence in charge variant characterization for therapeutic mAbs.
Benefits
- The Alliance iS Bio HPLC System with a high-pH kit provides a system compatible with a pH gradient ion-exchange separation for lysine variants of mAb
- The high-pH kit enabled stable performance of the Alliance iS Bio HPLC System under extreme pH conditions to ensure long-term reliability
