Determination of Buspirone and its Metabolite 1-(2-Pyrimidinyl)-Piperazine in Human Plasma by Liquid Chromatography Tandem Mass Spectrometry

Abstract

A sensitive, robust and high throughput mass spectrometry based method is described for the determination of buspirone and its active metabolite 1-(2-pyrimidinyl)-piperazine (1-PP) in human plasma. The method uses Oasis MCX solid phase extraction to extract the analytes from plasma. The extracts are analysed by liquid chromatography tandem mass spectrometry using thermally and pneumatically assisted electrospray ionisation and selected reaction monitoring. The method is both accurate and precise with both intra- and inter-assay precision (%CV) of <10% for both buspirone and 1-PP. The method provides a lower limit of quantification of 0.025 ng mL⁻¹ and 0.5 ng mL⁻¹ for buspirone and 1-PP respectively from 0.5 mL of human plasma, sufficient to monitor systemic concentrations of drug and active metabolite at therapeutic doses.