Chiral resolution of pantoprazole sodium and related sulfoxides by complex formation with bovine serum albumin in capillary electrophoresis.

The separation of enantiomers of pantoprazole sodium, omeprazole and lansoprazole by capillary zone electrophoresis using bovine serum albumin (BSA) as the chiral selector is described. Baseline separation of the three structurally related drugs was obtained after optimization of the most important experimental parameters. For this purpose, influences such as BSA concentration, pH and concentration of 1-propanol as organic modifier on the separation were investigated. Increasing concentrations of BSA improved the chiral resolution but lowered the sensitivity of the detection system. Discrimination of the enantiomers was observed only in a narrow pH range of 7-8. An optimum of pH 7.4 was a good compromise in terms of enantio-resolution and peak shape. 1-Propanol when added to the buffer system, improved the peak shape of the analytes and the resolution. The optimized method has been validated for pantoprazole sodium and is useful for routine analysis.