Enantiomeric separation of zolmitriptan by CE with a sulfated β-cyclodextrin chiral selector / 中国药科大学学报

ABSTRACT

Aim:To develop a practical chiral CE method for the quantitative determination of the unwanted enantiomer[( R )-enantiomer]presented in zolmitriptan. Methods:The background electrolyte was 20 mmol/L sodium dihydrogenphosphate solution with 1% S-β-CD,adjusted to pH 3.50 with phosphoric acid. A fused-silica capillary(60 cm×50 μm ID,effective length 51.5 cm)was used at 20 ℃ for the separation. The applied voltage was -30 kV. The samples were loaded by hydrodynamic injection(50 mbar pressure,6 s). UV was measured at 220 nm. Results:Zolmitriptan and its chiral impurity were baseline resolved ( R s=6.66). The linearity was good over the concentration range from 4 to 80 μg/mL( r =0.999 8) of ( R )-enantiomer. The injection precision (expressed as CV%) was 2.83%. The average recovery was 99.97%( n =9). The limit of detection was 1.5 μg/mL. The host-guest complex binding constants were 964 and 905 mol-1 for ( R )-enantiomer and zolmitriptan,respectively. Conclusion:The method is suitable for the determination of ( R )-enantiomer in zolmitriptan and binding constants of zolmitriptan enantiomers to S-β-CD.