Development of a CZE method for the determination of mizolastine and its impurities in pharmaceutical preparations using response surface methodology

A fast and selective CZE method for the determination of mizolastine and related impurities is described. Response surface methodology was applied to study the influence of phosphate/triethanolamine (TEA) buffer concentration, heptakis(2,3,6-tri-O-methyl)-beta-CD (TM beta CD) concentration, voltage and temperature. The optimum conditions were: 105 mM phosphate/TEA buffer (pH 3.0) containing 10 mM TM beta CD, temperature 19 degrees C and voltage 30kV. Validation of the method was performed in drug substance and drug product. Robustness was evaluated using a Plackett-Burman design, including pH among the considered factors. Applying the optimal conditions, the nine peaks were baseline separated in about 10 min. The method was applied to the quality control of mizolastine in controlled-release tablets.