Abstract: Objective To develop a method for the content determination of cinobufagin and resibufogenin in shuanglong capsule. Methods Analysis was carried out on a Phenomenex luna C18(250 mm×4.6 mm, 5μm) column, the mobile phase was acetonitrile water(50:50,v/v) at the flow rate of 0.8mL·min-1, and the detection wavelength was set at 296nm. Results The result showed that the method of analysis established in this study have good reproducibility and stability. The cinobufagin average recovery was 98.5% (RSD=0.55%,n=6); The resibufogenin average recovery was 101.0%(RSD=0.67%,n=6). Conclusion The method is accurate and repeatable, and it can be applied to control the quality of this drug.

Key words: Qilong capsule, cinobufagin, resibufogenin, RP-HPLC, assay