Simultaneous Determination of Tetracaine Hydrochloride and Ethacridine Lactate in Oral Cavity Ulcer Gel by HPLC

OBJECTIVE To establish an HPLC method for simultaneous determination of tetracaine hydrochloride and ethacridine lactate in oral cavity ulcer gel. METHODS The column of Thermo Hypersil BDS C₁₈(4.6 mm×150 mm, 5 μm) was used, the mobile phase was a mixture of acetontrile-water-triethylamine (30∶70∶0.5), UV detector was set to double detection wavelength, the detection wavelength was 270 nm and 310 nm for tetracaine hydrochloride and ethacridine lactate, respectively; the flow rate was 1 mL·min^-1, and the injection volume was 10 μL. RESULTS The linear range of tetracaine hydrochloride was 40.0-160.0 mg·L^-1(r=0.999?9), and the average recovery was 100.2%, RSD=2.08%. The linear range of ethacridine lactate was 38.1-152.4 mg·L^-1(r=0.999 8), and the average recovery was 99.7%, RSD=1.71%. CONCLUSION The method is simple, accurate, reproducible, and suitable for the simultaneous determination of tetracaine hydrochloride and ethacridine lactate in oral cavity ulcer gel.