Development and validation of a rapid chromatographic method for the analysis of flunarizine and its main production impurities

A rapid selective method for the analysis of flunarizine and its associated impurities was developed and validated according to ICH guidelines. The separation was carried out using a Thermo Scientific Hypersil Gold C18 column (50 mm×4.6 mm i.d., 1.9 μm particle size) with a gradient mobile phase of acetonitrile–ammonium acetate–tetrabutylammoniumhydrogen sulfate buffer, at a flow rate of 1.8 mL/min and UV detection at 230 nm. Naturally aged samples were also tested to determine sample stability. A profile of sample and impurity breakdown was also presented.