Quantitative determination of steroid acetates in pharmaceutical preparations by high performance liquid...

A high performance liquid chromatographic method is described for the rapid, quantitative determination of corticosteroid acetates in a variety of pharmaceutical preparations. The method not only separates the steroids from other ingredients in tablets, creams, ointments, lotions, or suspensions, but also from their probable degradation products. The steroid acetate is extracted from a tablet matrix or from a suspension with water and acetonitrile (50 + 50), or from a hexane suspension of a cream, ointment, or lotion with acetonitrile. A liquid chromatograph equipped with an accurate flow controller, a variable wavelength detector capable of measurement at 240 nm, and a 10 microL loop injector was used. Components were separated on a microBondpak C18 column with acetonitrile-water as the mobile phase. K' values of 10 commonly used steroid acetates are shown and compared with Rf values from thin layer chromatographic systems. Results were equivalent for cortisone acetate tablets assayed by both the proposed and the official USP methods. Other pharmaceutical preparations were assayed to test the method, with satisfactory results.