HPLC analysis of the novel antipsychotic drug quetiapine in human plasma

A precise and feasible high-performance liquid chromatographic (HPLC) method for the analysis of the novel antipsychotic drug quetiapine in plasma has been developed. The analysis was carried out on a C8 (150x/4.6 mm i.d., 5 micron) reversed-phase column, using a mixture of acetonitrile, methanol and pH 1.9 phosphate buffer as the mobile phase; triprolidine was used as the internal standard. Careful pretreatment of the biological samples was implemented by means of solid-phase extraction (SPE). A good linearity was found in the 4x400 ng/ml quetiapine plasma concentration range. The application to some plasma samples of patients treated with Seroquel tablets gave satisfactory results. The accuracy was good (quetiapine mean recovery 92%), as well as the precision (mean RSD 3.3%). The method seems to be suitable for the clinical monitoring of patients treated with quetiapine.