Pharmaceutical availability of betamethasone dipropionate and gentamicin sulfate from cream and ointment

Kinetics of drug release from both compared preparations occuring as a cream and ointment, was in vitro studied. A reversed-phase HPLC method was developed for the determination of betamethasone dipropionate in lipophylic bases. Analyses were performed using a PLRP column with a mobile phase of methanol-acetonitrile-water and ultraviolet detection at lambda = 254 nm. The calibration curve was constructed for concentration (.0-50.0 microg/ml. The method is simple, accurate and precise. For the determination of gentamicin sulfate the FPIA method was used.