Simultaneous Determination of Tetracaine Hydrochloride and Clotrimazole in Compound Neomycin Sulfate Pellicles by HPLC

OBJECTIVE To establish an HPLC method for simultaneous determination of tetracaine hydrochloride and clotrimazole in compound neomycin sulfate pellicles. METHODS An HPLC method was adopted. The column was Agilent HC-C₁₈, the mobile phase was a mixture of methanol-0.1% triethylamine solution(adjusted to pH 3.0 with phosphoric acid) (85∶15), the detection wavelength was 311 nm and 227 nm for tetracaine hydrochloride and clotrimazole, respectively, the flow rate was 0.8 mL·min^-1, the column temperature was maintained at 20 oC, and the injection volume was 20 μL. RESULTS The linear range of tetracaine hydrochloride was 2.5-50.0 mg·L^-1(r=0.999 5), and the average recovery was 99.3%, RSD=0. 99% (n=9). The linear range of clotrimazole was 5.33-106.5 mg·L^-1(r=0.999 5), and the average recovery was 99.8%, RSD=1.28% (n=9). CONCLUSION The method is simple, accurate, reproducible, and suitable for the simultaneous determination of tetracaine hydrochloride and clotrimazole in compound neomycin sulfate pellicles.