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 validated, High resolution a nd efficiency separations (R-S = 2.5 and 80 000 plates m(-1), respectively) were achieved by use of a teicoplanin chiral stationary phase in the polar organic mode. Method validation showed that detection linearity, robustness, accuracy, and repeatability were adequate. The method 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 commercial column was subsequently evaluated by use of the validated method and found to yield results for metoprolol comparable with those obtained on the home-packed columns. Acceptable separations on this commercial column were also obtained for other beta -blocking drugs; those for alprenolol were particularly noteworthy (R-s = 3.8 and 265 000 plates m(-1)).