Simple high-performance liquid chromatographic method for simultaneous determination of fusidic Acid and betamethasone dipropionate in a cream formulation.

A simple and selective high-performance liquid chromatography (HPLC) method using ultraviolet detection was developed for simultaneous determination of fusidic acid and betamethasone dipropionate in a cream formulation. A Supelcosil LC18 column was used for chromatographic separation. The mobile phase consisted of acetonitrile and 0.01 M disodium hydrogen orthophosphate (70:30, % v/v) adjusted to pH 6 with glacial acetic acid. Analysis was run at a flow rate of 1.0 mL/minute with the detector operating at 235 nm. The standard calibration curve was linear over a concentration range of 0.3 to 1.2 mg/mL for fusidic acid and 9.6 to 38.4 micrograms/mL for betamethasone dipropionate. The average recovery values for fusidic acid and betamethasone dipropionate were almost 100%. The within-run and between-run coefficient of variation and percent error values for the two drugs were all less than 2% and +/- 3%, respectively.