Validated UPLC-MS/MS method for determination of moclobemide in human brain cell supernatant and its application to bidirectional transport study.

A simple and sensitive analytical method based on ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) has been developed for determination of moclobemide in human brain cell monolayer as an in vitro model of blood-brain barrier. Brucine was employed as the internal standard. Moclobemide and internal standard were extracted from cell supernatant by ethyl acetate after alkalinizing with sodium hydroxide. The UPLC separation was performed on an Acquity UPLC(TM) BEH C18 column (50 × 2.1 mm, 1.7 µm, Waters, USA) with a mobile phase consisting of methanol-water (29.5:70.5, v/v); the water in the mobile phase contained 0.05% ammonium acetate and 0.1% formic acid. Detection of the analytes was achieved using positive ion electrospray via multiple reaction monitoring mode. The mass transitions were m/z 269.16 → 182.01 for moclobemide and m/z 395.24 → 324.15 for brucine. The extraction recovery was 83.0-83.4% and the lower limit of quantitation (LLOQ) was 1.0 ng/mL for moclobemide. The method was validated from LLOQ to 1980 ng/mL with a coefficient of determination greater than 0.999. Intra- and inter-day accuracies of the method at three concentrations ranged from 89.1 to 100.9% for moclobemide with precision of 1.1-9.6%. This validated method was successfully applied to bidirectional transport study of moclobemide blood-brain barrier permeability.

Classification of LC columns based on the QSRR method and selectivity toward moclobemide and its metabolites.

This paper focuses on a comparative study of the column classification system based on the quantitative structure-retention relationships (QSRR method) and column performance in real biomedical analysis. The assay was carried out for the LC separation of moclobemide and its metabolites in human plasma, using a set of 24 stationary phases. The QSRR models established for the studied stationary phases were compared with the column test performance results under two chemometric techniques - the principal component analysis (PCA) and the hierarchical clustering analysis (HCA). The study confirmed that the stationary phase classes found closely related by the QSRR approach yielded comparable separation for moclobemide and its metabolites. Therefore, the QSRR method could be considered supportive in the selection of a suitable column for the biomedical analysis offering the selection of similar or dissimilar columns with a relatively higher certainty.

Death of a female cocaine user due to the serotonin syndrome following moclobemide-venlafaxine overdose.

To our knowledge, the majority of evidence supporting the relationship between the serotonin syndrome and medications that effect 5HT is based on case reports. The justification for taking up this subject has been a fatal outcome of a 21 year-old female following an administration of toxic doses of moclobemide (MAOI) and venlafaxine (SNRI). As a result of complex toxicological investigations including antemortem and postmortem material, antemortem clinical observations and postmortem examinations, the cause of death was identified as overdose with antidepressants--moclobemide and venlafaxine--in the mechanism of the clinically fully developed severe toxic serotonin syndrome. The analysis of a hair strand collected from the victim documented the use of the above-mentioned drugs simultaneously with cocaine in the period of at least 20 months preceding death. The fact is a matter of considerable interest in view of the employed pharmacotherapy, giving rise to suspicion that the woman had not developed the serotonin syndrome during the almost 2-year antemortem period until she took toxic doses of both medications.

High-performance liquid chromatographic method for the determination of moclobemide and its two major metabolites in human plasma.

A selective, sensitive, and simple high-performance liquid chromatographic (HPLC) method was developed for the determination of moclobemide and its two major metabolites, Ro 12-5637 and Ro 12-8095, in human plasma. Sample preparation (0.5 ml of plasma) involved solid-phase extraction (SPE) using Speedisk H(2)O-Philic DVB columns. Separations were performed on a Waters XTerra RP18 column (5 microm, 150 mm x 4.6 mm). The mobile phase consisted of 10 mM KH(2)PO(4) with 1% triethylamine (pH 3.9) and acetonitrile (83:17, v/v), and a flow-rate was 1.2 ml/min. The total run time was 13 min. UV detection was performed at 240 nm. Mean absolute recoveries were > or =90% and the limit of quantification (LOQ) for all analytes was 0.02 mg/l. Calibration curves were linear (r>0.995) over a wide range of the analyte concentrations in plasma; thus, the method is suitable for different clinical studies when large variations in the drug/metabolites concentrations are observed. During a 5-day assay validation procedure the accuracy and precision were tested and proven (relative errors (RE)< or =13%; intra-day coefficient of variation (CV)< or =7%; inter-day CV< or =13%). Many drugs frequently used in the target patient population were evaluated for potential interference in order method selectivity to be ensured. The assay has been used in a clinical pharmacokinetic study to assess steady-state pharmacokinetics of moclobemide and two metabolites in depressive patients on mono- and combined therapy.

Determination of moclobemide, paroxetine, and fluvoxamine in tablets by HPLC.

A simple, accurate high performance liquid chromatography procedure is presented in order to determine moclobemide in Aurorix-tablets, paroxetine in Seroxat-tablets and fluvoxamine in Fevarin tablets. These drugs were chromatographed on a Nova-Pak C18, (dp = 4 microm), 150x3.9 mm i.d. column using methanol/phosphate butter adjusted to pH 2.65 with phosphoric acid (7:3, v/v) as the mobile phase to determining of the moclobemide and methanol/tetrahydrofuran/phosphate buffer at pH 2.65 (53:5:4, v/v) for determining of paroxetine and fluvoxamine. The detection was carried at 235 nm. The method was tested for linearity over the range 5-50 microg/ml. The relative standard deviation for moclobemide is 1.16, but for paroxetine and fluvoxamine is less than 1% (0.25 and 0.46 respectively).