Quantitative analysis of minaprine and some of its metabolites with application to kinetic studies in rats

A simple and rapid high-performance liquid chromatographic method is described for the quantitative analysis of the psychotropic drug minaprine and three of its metabolites (M1, M3 and M11), including one as yet undetected metabolite (M11) known as a monoamine oxidase type A inhibitor in vitro. After selective extraction all four compounds were separated on a reversed-phase muBondapak C18 column using sodium acetate (0.03 M)-acetonitrile-methanol (88:7:5) (pH 3.3) as the mobile phase. The eluted compounds were detected with a UV detector at 254 nm. The sensitivity of the method is 0.02 microgram per millilitre of body fluid or per gram of tissue for M1 and M11 and 0.05 microgram per minaprine and M3. The method has been applied successfully to the determination of minaprine and the metabolites in plasma and brain and is compared here with an gas-liquid chromatographic method with an electron-capture detector previously developed for the detection of minaprine and M11. M11 was identified in rat urine by gas chromatography-mass spectrometry.