title: Determination of the antidepressants maprotiline and amoxapine, and their metabolites, in plasma by liquid chromatography.
abstract: Maprotiline, amoxapine, and their metabolites were determined in plasma by three separate procedures, each of which involves a three-step extraction followed by reversed-phase separations. Amoxapine, maprotiline, and N-desmethylmaprotiline can be measured with use of a conventional C-18 column with 10% carbon load, but analyses for 7- and 8-hydroxyamoxapines require a small (5-microns) particle size, high carbon load, 20% C-18 column with 0.2 mol/L phosphate as mobile phase. Within-run and day-to-day CVs were 5% and 8%, respectively. Peak-height ratios were linearly correlated with concentrations between 0 and 400 micrograms/L. Detection limits ranged from 1 to 3 ng. Interference studies indicated that nortriptyline co-elutes with maprotiline. Assays of patients' plasma showed substantial amounts of these drugs and most of their metabolites, but only trace amounts of 7-hydroxyamoxapine.
mesh_terms: D000657:Amoxapine / Q000097:blood / Q000378:metabolism*; D000873:Anthracenes / Q000378:metabolism*; D000928:Antidepressive Agents / Q000097:blood / Q000378:metabolism*; D002853:Chromatography, Liquid / Q000379:methods; D003989:Dibenzoxazepines / Q000378:metabolism*; D006801:Humans; D008376:Maprotiline / Q000097:blood / Q000378:metabolism*
chemical_list: D000873:Anthracenes; D000928:Antidepressive Agents; D003989:Dibenzoxazepines; D008376:Maprotiline; D000657:Amoxapine