title: Rapid determination of venlafaxine and O-desmethylvenlafaxine in human plasma by high-performance liquid chromatography with fluorimetric detection.
abstract: A rapid and sensitive high-performance liquid chromatographic technique for simultaneous measurement of plasma venlafaxine (VEN) and its active metabolite O-desmethylvenlafaxine (ODV) is described. The process begins with the extraction of VEN and ODV, with maprotiline (MAP) as internal standard, from human plasma into an intermediate organic mixture of hexane-isoamyl alcohol and finally into an aqueous solution of 0.05% phosphoric acid. Isocratic separation of VEN, ODV and MAP is carried out by utilizing a reversed-phase butyl-bonded column (C4/E) with mobile phase consisting of acetonitrile and 40 mM phosphate buffer, pH 6.8 (50:50, v/v). Detection of VEN, ODV and MAP is done by mean of fluorimetry with excitation and emission wavelengths set at 276 and 598 nm, respectively. As low as 1.0 ng/ml VEN is detectable; while the limit of detection for ODV is 5 ng/ml. C.V. (%) of intra-day samples for both VEN and ODV are less than 10% at three concentrations tested (10.0, 50.0, 100.0 ng/ml). Similarly, over the same nominal concentrations, the precision of inter-day (5 days) samples also results in C.V. (%) smaller than 10% for both compounds, except for ODV measured at 10 ng/ml (C.V.<15%). Approximately, 100% VEN can be extracted from plasma; whereas, for ODV the recovery rate is nearly 70%. This present method is rapid, sensitive, accurate and simple for routine clinical monitoring of plasma VEN and its major metabolite ODV.
authors.affiliation: VA Medical Center, Long Beach, CA 90822, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Vu
authors.forename: D
authors.initials: D
authors.lastname: Helmeste
authors.forename: L
authors.initials: L
authors.lastname: Albers
authors.forename: C
authors.initials: C
authors.lastname: Reist
mesh_terms: D018687:Antidepressive Agents, Second-Generation / Q000097:blood* / Q000737:chemistry / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002940:Circadian Rhythm; D003511:Cyclohexanols / Q000097:blood* / Q000737:chemistry / Q000378:metabolism; D000069468:Desvenlafaxine Succinate; D006801:Humans; D016014:Linear Models; D009994:Osmolar Concentration; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence; D000069470:Venlafaxine Hydrochloride
chemical_list: D018687:Antidepressive Agents, Second-Generation; D003511:Cyclohexanols; D000069470:Venlafaxine Hydrochloride; D000069468:Desvenlafaxine Succinate