Bioanalysis of trifluoperazine in human plasma by LC-MS/MS: Application to disposition kinetics

A sensitive, selective and rapid bioanalytical method using liquid chromatography-tandem mass spectrometry has been developed for the quantification of trifluoperazine in human plasma. Trifluoperazine-D₈ was used as the internal standard and the extraction from human plasma was performed by liquid-liquid extraction technique using tertiary butyl methyl ether as the solvent. Chromatographic separation was carried out on Zodiac C₁₈ column (50 × 4.6 mm, 3 μm) employing a mixture of acetonitrile, methanol and 5 mm ammonium bicarbonate buffer in water (85:10:5, v/v/v) at a flow rate of 0.55 ml/min. The linearity was established within the concentration range of 5-1,250 pg/ml with r²  > 0.99. The results of all of the validation parameters as per the US Food and Drug Administration guidelines were within the acceptance limits. The pharmacokinetics of trifluoperazine after oral administration of a syrup of 1 mg dose under fasting conditions was determined by successful application of the present method.