Determination of the three compounds in sulfamethoxazole,sulfadiazine and trimethoprim tablets by HPLC

Objective: To establish a method to determine the contents of three compounds in Sulfamethoxazole,Sulfadiazine and Trimethoprim Tablets.Methods: The contents were determined by HPLC with C18 column(4.6 mm×250 mm,5 μm).The mobile phase was 0.025 mol/L phosphate solution-acetonitrile(80:20) and the detection wavelength was at 220 nm.Results: The Sulfamethoxazole,Sulfadiazine and Trimethoprim was linear within the ranges of 40 ~ 240 μg/ml(r = 0.9999),40 ~ 240 μg/ml(r = 0.9999) and 16 ~ 96 μg/ml(r = 0.9995) respectively.The average recovery was 100.4%(RSD = 0.30%),100.4%(RSD = 0.21%) and 101.7%(RSD = 1.29%),respectively.Conclusion: This method is fast,simple and reproducible.