Determination of Betamethasone Dipropionate and Salicylic Acid in Pharmaceutical Preparations by High-Performance Liquid Chromatography

Abstract The simultaneous determination of betamethasone dipropionate (BD) and salicylic acid (SA) in both ointment and topical solution was developed using high-performance liquid chromatography (HPLC). The method was standardized using a LiChrospher(r) 100 RP-18 (125 × 4 mm, 5 μm) column, acetonitrile-tetrahydro-furan-acetic acid 1 % (25:20:55 v/v), apparent pH 3.3, as mobile phase, and UV detection at 254 nm. The peak area response versus concentration was linear in a concentration range from 5.0 to 50.0 μg/ml of BD and from 20.0 to 200.0 μgl ml of SA. The correlation coefficients were 0.9997 for BD and 0.9987 for SA, and the relative standard errors of estimates were 1.38% for BD and 3.27% for SA. The coefficient of variation and the recovery average were, respectively, 0.41-1.15% and 100.09% for BD, and 0.57-0.95% and 99.79% for SA.