title: Rapid determination of finasteride in human plasma by UPLC-MS/MS and its application to clinical pharmacokinetic study.
abstract: A rapid, specific, and sensitive method utilizing reversed-phase ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed and validated to determine finasteride levels in human plasma. The plasma samples were prepared by liquid-liquid extraction with ethyl acetate, evaporation, and reconstitution. MS/MS analyses were performed on a triple-quadrupole tandem mass spectrometer by monitoring protonated parent-->daughter ion pairs at m/z 373-->305 for finasteride and m/z 237-->194 for carbamazepine (internal standard, IS). The method was validated with respect to linearity, recovery, specificity, accuracy, precision, and stability. The method exhibited a linear response from 0.1 to 30 ng/mL (r(2)>0.998). The limit of quantitation for finasteride in plasma was 0.1 ng/mL. The relative standard deviation (RSD) of intra- and inter-day measurements was less than 15% and the method was accurate within -6.0% to 2.31% at all quality-control levels. The mean extraction recovery was higher than 83% for finasteride and 84% for the IS. Plasma samples containing finasteride were stable under the three sets of conditions tested and the processed samples were stable up to 29 h in an autosampler at 5 degrees C. Detection and quantitation of both analytes within 3 min make this method suitable for high-throughput analyses. The method was successfully applied to a pharmacokinetic study of finasteride in healthy volunteers following oral administration.
authors.affiliation: Department of Molecular Medicine, Kyungpook National University School of Medicine, Daegu, South Korea.
authors.forename: Prasad B
authors.initials: PB
authors.lastname: Phapale
authors.forename: Hae Won
authors.initials: HW
authors.lastname: Lee
authors.forename: Mi-sun
authors.initials: MS
authors.lastname: Lim
authors.forename: Eun-Hee
authors.initials: EH
authors.lastname: Kim
authors.forename: Sung-Doo
authors.initials: SD
authors.lastname: Kim
authors.forename: Jeonghyeon
authors.initials: J
authors.lastname: Park
authors.forename: Miran
authors.initials: M
authors.lastname: Lee
authors.forename: Sung-Kyu
authors.initials: SK
authors.lastname: Hwang
authors.forename: Young-Ran
authors.initials: YR
authors.lastname: Yoon
mesh_terms: D000328:Adult; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D018120:Finasteride / Q000097:blood* / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D018120:Finasteride