title: Determination of paroxetine in geriatric depression by high-performance liquid chromatography.
abstract: An HPLC method was developed for the determination of paroxetine in depressed geriatric patients. This method includes only one-step extraction of paroxetine from 1 ml of plasma with hexane:isoamyl alcohol (99:1, v/v). Separation was obtained using an RP select B column (250 mm x 4 mm, 5 microm) under isocratic conditions with UV detection (lambda=205 nm). The mobile phase was 0.05 mol/l sodium phosphate buffer, pH 5.0, and acetonitrile (50:50, v/v). The intra- and inter-assay accuracy and precision, determined as relative error and relative standard deviation, respectively, were less than 10%. The lower limit of quantification, with relative error and relative standard deviation of less than 10%, was 5 ng/ml. Linearity was assessed in the 5-1250 ng/ml range and recovery was 80%. Neither endogenous compounds nor other drugs were found to interfere. The assay showed high specificity, even when patients were found to be on multiple medications. In conclusion, the present method, when compared to others reported in the literature, has advantages such as simplicity, selectivity and sensitivity as a routine procedure and can be applied to the therapeutic monitoring of depressed geriatric patients.
authors.affiliation: Department of Clinical, Toxicological and Food Science Analysis, Faculty of Pharmaceutical Sciences of São Paulo, Av. do Café s/n, S.P. 14040-903, Ribeirão Preto, Brazil.
authors.forename: Isis A
authors.initials: IA
authors.lastname: Zainaghi
authors.forename: Vera L
authors.initials: VL
authors.lastname: Lanchote
authors.forename: Regina H C
authors.initials: RH
authors.lastname: Queiroz
mesh_terms: D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003863:Depression / Q000097:blood* / Q000188:drug therapy; D004347:Drug Interactions; D016903:Drug Monitoring / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D017374:Paroxetine / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017367:Selective Serotonin Reuptake Inhibitors / Q000097:blood*
chemical_list: D017374:Paroxetine; D017367:Selective Serotonin Reuptake Inhibitors