ABSTRACT
OBJECTIVE: To develop a gradient supercritical fluid chromatography method for the separation of cinnarizine and its four related substances. METHODS: Cinnarizine and its four related substances were separated on a Torus DIOL column (3.0 mm×100 mm,1.7 μm) maintained at 40 ℃ with the mobile phase consisting of CO2 and methanol with 0.1% TFA-0.1% TEA at 1.5 mL•min-1, the detection wavelength was set at 230 nm and the back pressure was set at 1.38×107 Pa. RESULTS: Cinnarizine and its four related substances were separated in 4.5 min with satisfying resolutions. Good linear relationships were established between the peak response and the concentration in the range of 2-20 μg•mL-1 for each related substance (r>0.999 9) and the detection limits were 0.7-1.3 ng(S/N≥3). Good linear relationships were established between the peak response and the concentration in the range of 0.05-1.0 μg•mL-1 for cinnarizine (r=1.000 0). The spiked recovery of four related substances of cinnarizine was 98.0%-106.7%, and the RSD was 2.57%-4.44%(n=9). CONCLUSION: The established method can be applied in the simultaneous determination of the related substances of cinnarizine and provide reference for the quality control.