Simultaneous determination of nilotinib, imatinib and its main metabolite (CGP-74588) in human plasma by ultra-violet high performance liquid chromatography.

We describe a high performance liquid chromatography (HPLC) method that separates two of the currently licenced tyrosine kinase inhibitors (TKIs); nilotinib (AMN107, Tasigna) and imatinib (STI571, Glivec), together with its main metabolite, CGP-74588, from human plasma. After solid phase extraction the drug mix was separated through a Gemini C6-phenyl column (150 mm x 4.6mm, i.d.; 5 microm) (Phenomenex), UK) under isocratic mobile phase conditions of methanol:50mM ammonium acetate (pH 8) (65:35, v/v) with ultra-violet (UV) detection at 260 nm wavelength. For all compounds the intra-day coefficient of variation and bias were <3% and <5% respectively; and inter-day were <4% and <9%. This simple and novel method may be used to quantify levels of TKIs when used alone or in combination with drug treatments for clinical samples.