A selective, sensitive and accurate high-performance liquid chromatographic- tandem mass spectrometry (HPLC-MS/MS) method for simultaneous determination of iloperidone and its two active metabolites, P88 and P95, in human plasma has been first developed and validated. The analytes and internal standard (IS), pioglitazone hydrochloride, were extracted from human plasma via liquid-liquid extraction with ethyl acetate and separated on a CAPCELL PAK C18 MG IIIcolumn (150 mm × 2.0 mm, 5 μm) set at 40. °C. The mobile phase was acetonitrile: 5 mM a...