| Ion exchange chromatography is widely used for charge variant analysis of proteins, including monoclonal antibodies. In this
study, a simple and robust salt gradient cation exchange chromatography was developed and validated for quantitative determination
of cetuximab in biopharmaceutical formulations. For this purpose, we investigated the effect of various parameters
including buffer composition, column temperature, pH, gradient volume and flow rate on chromatographic separation of
charge variants to achieve the acceptable peak separation, and the optimum condition was selected. Validation of the method
was done in accordance with the International Conference on Harmonization (ICH) guidelines. The developed method was
found to provide a linear regression over the concentration range of 0.06–2.00 mg mL−
1 yielding a correlation coefficient
of 0.9972. The limits of detection and quantification for the developed method were 0.02 and 0.06 mg mL−
1, respectively.
The intra-day and inter-day precision had relative standard deviation values ≤ 2.7%. The robustness of the method was
assessed by changes in the applied pH range of buffer, temperature, mobile phase composition, and flow rate. Specificity of
the method was confirmed by evaluation of baseline resolution of the mAb variants from product excipients, which showed
no interference between excipients and cetuximab. The stability indicating capability of this method was determined using
photodegraded, and mechanically and thermally stressed samples. The proposed method could be applied as a simple, precise,
and robust quantitative technique which can be reproduced in any labs for the high-throughput quality control and stability
assessment of in-process and final product samples. |