Simultaneous analytical method for the determination of TCH346 and its four metabolites in human plasma by liquid...

TCH346 (dibenzo[b,f]oxepin-10-ylmethyl-prop-2-ynylamine) is a novel propargylamine compound under investigation as a putative agent in the treatment of chronic neurodegenerative illnesses. To support clinical studies an analytical method was developed for TCH346 plus its three amine metabolites and a carboxylic acid metabolite in human plasma. Using a two-step liquid-liquid extraction, one under acidic and one under basic conditions, by pH-switching both the basic and acidic analytes were extracted from 0.5 mL of plasma. All these basic and acidic compounds could be analyzed simultaneously using gradient high-performance liquid chromatographic (HPLC) separation with positive/negative selected reaction monitoring mass spectrometry. As a result of the validation study, the analytical method was shown to be appropriate for the determination of TCH346 and its metabolites CGP70861, GP42120, CGP71090, and GP54840 in plasma for forthcoming clinical studies. The LLOQs were set to 2, 200, 20, 20, and 200 pg/mL for TCH346, CGP70861, GP42120, CGP71090, and GP54840, respectively, and the ULOQ for all analytes was 20 000 pg/mL. All analytes were stable in 50% MeOH at 4 degrees C for at least one year, in human plasma stored below -70 degrees C for at least 7 months, in human plasma below -18 degrees C for at least 6 months, in human plasma at room temperature for at least 1 day, and in the final extract solution at 4 degrees C for at least 3 days.