title: HPLC analysis of the novel antidepressant duloxetine in human plasma after an original solid-phase extraction procedure.
abstract: Duloxetine is the most recent serotonin and norepinephrine reuptake inhibitor (SNRI) drug introduced for the therapy of depression. Thus, it is evident that there is a need for having on hand new reliable analytical methods for the determination of duloxetine plasma levels in depressed patients. The present paper deals with the development of a rapid and sensitive high-performance liquid chromatographic method for duloxetine analysis in human plasma. The assays were carried out using a C8 reversed-phase column and a mobile phase composed of 60% aqueous phosphate buffer containing triethylamine at pH 3.0 and 40% acetonitrile. The UV detector was set at 230 nm and loxapine was used as the internal standard. An original pre-treatment of plasma samples was developed, based on solid-phase extraction (SPE) with mixed-mode reversed phase-strong cation exchange cartridges (30 mg, 1 mL). The extraction yields values were higher than 90%. Linearity was found in the 2-200 ng mL(-1) duloxetine concentration range; the limit of quantitation was 2.0 ng mL(-1) and the limit of detection was 0.7 ng mL(-1). The method was applied to plasma samples from depressed patients undergoing therapy with duloxetine. Precision data and accuracy results were satisfactory and no interference from other drugs was found. Thus, the method seems to be suitable for the therapeutic drug monitoring of duloxetine in depressed patients' plasma.
authors.affiliation: Pharmaco-Toxicological Analysis Laboratory, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Alma Mater Studiorum, University of Bologna, Via Belmeloro 6, I-40126 Bologna, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Mercolini
authors.forename: Roberto
authors.initials: R
authors.lastname: Mandrioli
authors.forename: Roberto
authors.initials: R
authors.lastname: Cazzolla
authors.forename: Mario
authors.initials: M
authors.lastname: Amore
authors.forename: Maria Augusta
authors.initials: MA
authors.lastname: Raggi
mesh_terms: D000928:Antidepressive Agents / Q000097:blood* / Q000627:therapeutic use; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003863:Depression / Q000097:blood* / Q000188:drug therapy; D000068736:Duloxetine Hydrochloride; D006801:Humans; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet; D013876:Thiophenes / Q000097:blood* / Q000627:therapeutic use
chemical_list: D000928:Antidepressive Agents; D013876:Thiophenes; D000068736:Duloxetine Hydrochloride