Development and validation of dissolution test for betamethasone injectable suspension

SHEN Dan-dan; WU Qun; ZHANG Tao

Abstract：Objective:To develop a method for determination of the dissolution of sustained release betamethasone dipropionate injectable suspension.Methods:An Agilent ZORBAX SB-C18 column (150 mm × 4.6 mm,5 μm) was used.The mobile phase was methanol-acetonitrile-0.01 mol· L-1 ammonium dihydrogen phosphate (34∶ 32∶34),the flow rate was 1.0 mL· min-1,the detection wavelength was set at 242 nm,and the column temperature was 35 ℃.The dissolution medium was screened among pH 7.4 sodium phosphate buffer,pH 7.4 simulated body fluid,pH 7.0 simulated muscular fluid and pH 7.4 simulated synovial fluid,each containing different concentrations of surfactant.The dissolution profiles were studied by the paddle apparatus,with stirring speed of 50 r· min-1.Results:There was a good linear relationship between the concentration and peak area in the range of 0.209 8 ～ 13.989 4 μg· mL-1 for betamethasone dipropionate;the average recovery (n =9) was 100.15％ (RSD =1.1％).The dissolution curve with a suitable degree of distinction could be obtained by using pH 7.4 sodium phosphate buffer containing 0.05％ sodium dodecyl sulfate as dissolution medium.The dissolution behavior of betamethasone dipropionate measured in different dissolution media had no significant difference.Conclusion:The method is simple and accurate.It can be used for determination of the dissolution of betamethasone dipropionate injectable suspension,which is beneficial to improve the quality controllability of the product.