title: A rapid, simple, liquid chromatographic-electrospray ionization, ion trap mass spectrometry method for the determination of finasteride in human plasma and its application to pharmacokinetic study.
abstract: A fast, accurate, sensitive, selective and reliable method using reversed-phase high performance liquid chromatography coupled to electrospray ionization ion trap mass spectrometry was developed and validated for the determination of ﬁnasteride in human plasma. After protein precipitation with perchloric acid, satisfactory separation was achieved on a Zorbax Eclipse(®) C8 analytical column using a mobile phase consisted of acetonitrile, 2 mM ammonium formate buffer (58:42, pH adjusted at 2.5 using formic acid); the flow rate was 0.25 mLmin(-1) and the column oven was set to 50°C. Tamoxifen citrate was used as internal standard. This method involved the use of [M +H](+) ions of ﬁnasteride and IS at m/z 373 and 372 respectively with the selected ion monitoring (SIM) mode. The calibration curve was linear over the range of 0.1-60 ng mL(-1). The limit of quantiﬁcation for ﬁnasteride in plasma was 0.1 ng mL(-1). The intra-day and inter-day repeatability (precision) were 2.68-13.87% and 2.14-14.69% respectively. Intra-day and inter-day accuracy were 98-101.57% and 99.7-110%. The assay method has been successfully used to estimate the pharmacokinetics of ﬁnasteride after oral administration of a 5 mg tablet of ﬁnasteride in 12 healthy volunteers.
authors.affiliation: Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran .
authors.forename: Syed Husain
authors.initials: SH
authors.lastname: Hashemi Mousavi
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Phytochemistry Research Center, SBMU, Tehran, Iran.
authors.forename: Farzad
authors.initials: F
authors.lastname: Kobarfard
authors.affiliation: Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran .
authors.forename: Syed Waqif
authors.initials: SW
authors.lastname: Husain
authors.affiliation: Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran .
authors.forename: Mohammad Saber
authors.initials: MS
authors.lastname: Tehrani
authors.affiliation: Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran .
authors.forename: Parviz
authors.initials: P
authors.lastname: Abroomand Azar
authors.affiliation: Pharmacutical Sciences Research Center, Tehran University of Medical Science.
authors.forename: Reza
authors.initials: R
authors.lastname: Ahmadkhaniha
authors.affiliation: Kimia R&D Institute, Tehran, Iran.
authors.forename: Amir
authors.initials: A
authors.lastname: Mehdizadeh
keywords: Electrospray ionization (ESI); Finasteride; Ion trap; Liquid chromatography–mass spectrometry (LC–MS); Pharmacokinetic