Validation of a chiral capillary electrochromatographic method for metoprolol on a teicoplanin stationary phase

A chiral capillary electrochromatographic (CEC) method for determination of the enantiomeric purity of ei ther enantiomer of metoprolol has been valid ated, High resolution a nd efficiency separations (R-S = 2.5 and 80 000 pla tes m(-1), respectively) were achieved by use of a teicoplanin chiral stati onary phase in the polar organic mode. Method validation showed that detect ion linearity, robustness, accuracy, and repeatability were adequate. The m ethod was also shown to be sufficiently sensitive for the determination of a mi nor enantiomer; the limit of quantitation (LOQ) was determined to be 0 .09% of the peak area of the enantiomer under investigation. A similar comm ercial column was subsequently evaluated by use of the validated method and found to yield results for metoprolol comparable with those obtained on th e home-packed columns. Acceptable separations on this commercial column wer e also obtained for other beta -blocking drugs; those for alprenolol were p articularly noteworthy (R-s = 3.8 and 265 000 plates m(-1)).