Liquid chromatographic-mass spectrometric determination of itraconazole and its major metabolite, hydroxyitraconazole, in dog plasma

A fast, reliable and sensitive liquid chromatography-mass spectrometry (LC-MS) assay for the determination of itraconazole and hydroxyitraconazole in dog plasma has been developed. The analysis involves a simple liquid-liquid extraction followed by LC-MS analysis using electrospray ionization in the positive mode. Total separation of itraconazole, hydroxyitraconazole and the internal standard, miconazole, was achieved on a C-18 column in 3.5 min using an isocratic mixture of acetonitrile and 10 mM ammonium acetate. The response was linear over four-orders of magnitude, allowing reliable quantification of each species. This paper describes the development of the method and its validation. (C) 2000 Elsevier Science B.V. All rights reserved.