A sensitive high-performance liquid chromatographic method using electrochemical detection for the analysis of olanzapine and desmethylplanzapineinplasma of schizophrenic patients using a new solid-phase extraction procedure

摘要

A high-performance liquid chroatographic metbod with amperometric detection for the analysis of the novel antips~choIic dnig otam7.apine and its meiabolite desmethy[olanzapine in human plasma has been developed. The analysis was carried out on a reversed-phase column (C_8, 150X4.6 innx Iii, S ~gn) using acetonitrile-phosphate buffer, p11 3.8. as the mobile phase. The detection voltage was +800 mV and the cell and column temperature was 300C. The flow-rate was 1.2 ml min1. Linear responses were obtained between 5 and 150 ng ml ~‘, with repeatability <3.3%. A careful pretreatment ot the biological samples was implemented by means of solid-phase extraction (SPE) on C8 cartridges. The method requires 500 pi of plasma for one complete analysis. Absolute recovery exceeded 97% for both olanzapine and desmethylolanzapme. and the detection limit was I ng ml -‘ for both analytes. Repeatability, intermediate precision and accuracy were satisfactory. This sensitive and selective method has been successfully applied to therapeutic drug monitoring in schizophrenie patients treated with Zyprexa tablets.