QUANTITATIVE-DETERMINATION AND PHARMACOKINETICS OF A NEW ANTIPSYCHOTIC (CGS 13429A) IN HUMAN PLASMA USING CAPILLARY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

A quantitative analytical method is described for the determination of a new antipsychotic (CGS 13429A) in human plasma. The method relies o n capillary gas chromatography/mass spectrometry in the positive chemi cal ionization mode, utilizing ammonia reagent gas. The limit of quant ification (LOQ) was 0.1 ng ml(-1) and the method was Validated over a concentration range of 0.1-50 ng ml(-1). The method was used to measur e CGS 13429A plasma concentrations following the administration of sin gle oral ascending doses ranging from 0.1 to 10 mg in healthy male vol unteers. The drug was rapidly absorbed (Tmax ranged from 1.1 to 3.7 h) and showed a mean terminal elimination half-life of 8.1 h, which was independent of dose. Area-under-the-curve (AUC) along with Cmax values were proportional to the administered dose.