DETERMINATION OF RALOXIFENE HYDROCHLORIDE IN HUMAN URINE BY LC-MS-MS

A sensitive and selective liquid chromatographic-tandem mass spectrometric (LC-MS-MS) method was developed to determine raloxifene hydrochloride (RLX) in human urine. After a solid-phase extraction with SPE cartridge, the urine sample was analyzed on a C-18 column (Symmetry 3.5 mu m; 50 mmx4.6 mm id) interfaced with a triple quadruple tandem mass spectrometer. A positive electrospray Ionization was employed as the Ionization source. The mobile phase consisted of ammonium acetate (pH 4.0)-acetonitrile (60.40, v/v). The method was linear over a concentration range of 20-1000 ng mL(-1). The lower limit of quantitation was 20 ng mL(-1). The intra-day and inter-day relative standard deviation across three validation runs over the entire concentration range was <10.5%. The accuracy determined at three concentrations (50, 500 and 850 ng mL(-1) RLX) was within +/- 0.84% in terms of relative errors.