BackgroundA method for determining nilotinib concentration in human plasma is proposed using high-performance liquid chromatography and ultraviolet detection. Materials & MethodsNilotinib and the internal standard dasatinib were separated using a mobile phase of 0.5% Na2PO4H2O (pH 2.5)-acetonitrile-methanol (55:25:20, v/v/v) on a Capcell Pak C18 MG II column (250 x 4.6 mm) at a flow rate of 1.0 ml/min, and ultraviolet measurement at 250 nm. ResultsThe calibration curve exhibited linearity over the nilotinib concentration range of 50-2,500 ng/ml at 250 nm, with relative standard deviations (n = 5) of 7.1%, 2.5%, and 2.9% for 250, 1,500, and 2,500 ng/ml, respectively. The detection limit for nilotinib was 5 ng/ml due to three blank determinations ( = 3). ConclusionThis method was successfully applied to assaying nilotinib in human plasma samples from patients with chronic myelogenous leukemia. In addition, we compared the results with those measured by liquid chromatographytandem mass spectrometry (LC-MS/MS) at BML, Inc. (a commercial laboratory). A strong correlation was observed between the nilotinib concentrations measured by our high-performance liquid chromatographic method and those obtained by LC/MS-MS (r(2) = 0.988, P < 0.01).