Fast analysis of glibenclamide and its related substances by capillary electrophoresis

A fast and reliable capillary zone electrophoresis method was set up for the simultaneous determination of glibenclamide (GLI), an antidiabetic drug belonging to the class of sulfonylureas, and its main impurities reported in European Pharmacopeia. The method was developed following QbD principles according to ICH guideline Q8, implementing each step of QbD workflow for separation methods as recently reported. The analytical target profile was defined by the baseline separation and the accurate determination of GLI and its impurities in the pharmaceutical dosage form, with LOQ values for the impurities equal or lower to 0.1% with respect to the main compound. In the screening phase different critical process parameters, each studied at three levels by a symmetric screening matrix, were taken into consideration: voltage, temperature, background electrolyte concentration and pH, injection time. The subsequent response surface study was carried out by using a Box-Behnken design and allowed the design space to be identified. By applying the selected working conditions, a complete separation of the analytes was obtained in less than 2 min. The developed method was validated according to ICH guideline Q2(R1) and then applied to the analysis of real samples of glibenclamide tablets.