Abstract: Objective To determine the content of ephedrine hydrochloride in Shexiangzhuifeng ointmen by HPLC. Methods HPLC with Welch polar ether linked phenyl column (5 µm, 150 mm×4.6 mm) was employed by using methyl cyanide-0.092% H₃PO₄ (0.04% triethylamine and 0.02% dibutylamine) (1.5:98.5) as the mobile phase. The flow rate was 1.0 mL·min^-1. The detection wavelength was set at 210 nm. The sample size was 10 µL. Results Ephedrine hydrochloride was in good linear relationship within the rage of 1.66×10^-4~0.244 µg, r=0.999 9. The mean recovery rate was 101.8% and RSD was 1.2%. Conclusion The HPLC method established here for analyzing the ephedrine hydrochloride in Shexiangzhuifeng ointmen is accurate, convenient and specific, which can be used for the quality control (QC).

Key words: Shexiangzhuifeng ointmen, HPLC, ephedrine hydrochloride, content determination