Validation and robustness testing of a CEC method used to determine impurities in a pharmaceutically active compound

Capillary electrochromatography (CEC) is a versatile new technique used to complement other separation techniques like HPLC. The main advantage of CEC over HPLC is the electrically driven flow, which generates a flat flow profile and provides sharper peaks and better efficiencies. In CEC the flow profiles within the channels between the particles are plug-like (as in CE), In HPLC (pressure driven flow) the flow profiles within similar channels are parabolic leading to band broadening. Hence efficiencies seen in HPLC are not as good as those obtained from CEC. This advantage along with the suitability of CEC with miniaturisation has led to extensive development of the technique. CEC has progressed significantly in recent years and numerous examples of CEC applications have been published. However most of the work has been carried out in a research environment. In order to progress the technique in the pharmaceutical industry it is necessary to demonstrate that CEC can be a robust and reliable technique. In this article we discuss the validation and robustness testing of a capillary electrochromatography method used for the determination of impurities in a potential drug substance. The CEC method was developed and validated in accordance with the ICH guidelines. The data generated was compared with the data from the existing HPLC method. Overall results show that CEC can be used in a highly regulated environment.