Determination of two ingredients in compound betamethasone injection by high performace liquid chromatography

Objective To establish the determination of two ingredients in compound betamethasone injection.Methods ODSC18(250 mm×4.6 mm,5 μm)was used with the mobile phase consisted of methanol:0.05 mol/L potassium dihydrogen phosphate solution(64:36).The flow rate was 1.0 ml/min and the detection wavelength was at 254 nm.Results The line range was 2.67 to 16.05 mg/ml for betamethasone dipropionate and 1.05～6.30 mg/ml for betamethasone sodium phosphate.The average recoveries were 100.2%and 99.4%,the RSD were 1.7%and 1.4%.Conclusion The mothod is simple,rapid and accurate.It can be used for the determination of two ingredients in compound betamethasone injection.