Enantioselective analysis of amisulpride in pharmaceutical formulations by means of capillary electrophoresis

A capillary electrophoretic method has been developed for the enantioselective analysis of amisulpride in pharmaceutical formulations, using β-cyclodextrin sulfate as the chiral selector. Several parameters, such as cyclodextrin type and concentration, buffer concentration and pH and capillary temperature were investigated for method optimisation. Baseline enantioseparation of the racemic compound was achieved in less than 10 minutes using a fused silica capillary (50 μm I.D. and 33.0 cm, 8.5 cm, total and effective length, respectively), filled with a background electrolyte consisting of a 10 mM citrate buffer at pH 3.5 supplemented with 0.22% (w/v) β-cyclodextrin sulfate at 20°C and applying a voltage of +15 kV. Formulation analysis was carried out after analyte extraction by methanol. The method was fully validated, with good results in terms of precision, selectivity, accuracy and amount of drug found with respect to the label claim. Thus, the method seems to be suitable for the enantiomeric analysis of amisulpride in pharmaceutical formulations.