VALIDATED METHOD FOR THE DETERMINATION OF IDAZOXAN IN HUMAN PLASMA BYLIQUID-CHROMATOGRAPHY WITH TANDEM MASS-SPECTROMETRIC DETECTION

A liquid chromatography-tandem mass spectrometry method for the determ ination of idazoxan in human (heparin) plasma is presented, which was developed and validated using 500 mu l of sample. Sample preparation c onsisted of the addition of fluoroidazoxan as the internal standard, e xtraction at alkaline conditions into tert.-butyl methyl ether, follow ed by centrifugation, evaporation of the solvent and reconstitution in methanol. After a short chromatographic run, detection took place by ionspray tandem mass spectrometry in positive ion mode. Validation res ults on linearity, specificity, accuracy, precision and stability, as well as application of the method to samples from a clinical trial, ar e shown. The validated calibration range is from 0.300 to 100 ng/ml, w ith accuracy (bias) and precision (coefficient of variation) being bel ow 15% at all levels. A sample throughput of, typically, 150 per day c an be achieved. (C) 1998 Elsevier Science B.V.