title: Verapamil quantification in human plasma by liquid chromatography coupled to tandem mass spectrometry. An application for bioequivalence study.
abstract: An analytical method based on liquid chromatography with positive ion electrospray ionization (ESI) coupled to tandem mass spectrometry detection (LC-MS/MS) was developed for the determination of Verapamil in human plasma using Metoprolol as the internal standard. The analyte and internal standard were extracted from the plasma samples by liquid-liquid extraction and chromatographed on a C(8) analytical column. The mobile phase consisted of methanol-water (70:30; v/v)+12 mM formic acid. The method had a chromatographic total run time of 3.5 min and was linear within the range 1.00-500 ng/mL. Detection was carried out on a Micromass Quattro Ultima tandem mass spectrometer by multiple reaction monitoring (MRM). The intra-run imprecision was less than 5.1% calculated from the quality control (QC) samples, and 16.3% from the limit of quantification (LOQ). The accuracy determined from QC samples were between 92.9 and 103.1%, and 95.2 and 115.3% from LOQ. Concerning the inter-batch analysis, the imprecision was less than 5.8% and 17.3% from QC samples and LOQ, respectively. The accuracy varied between 98.2 and 100.8% from QC and it was 103.1% from LOQ. The protocol herein described was employed in a bioequivalence study of two tablet formulations of Verapamil.
authors.affiliation: Department of Pharmacology, State University of Campinas, P.O. Box 6111, Campinas, SP, Brazil.
authors.forename: Ney Carter
authors.initials: NC
authors.lastname: do C Borges
authors.forename: Gustavo D
authors.initials: GD
authors.lastname: Mendes
authors.forename: Rafael E
authors.initials: RE
authors.lastname: Barrientos-Astigarraga
authors.forename: Paulo
authors.initials: P
authors.lastname: Galvinas
authors.forename: Celso H
authors.initials: CH
authors.lastname: Oliveira
authors.forename: Gilberto
authors.initials: G
authors.lastname: De Nucci
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D004355:Drug Stability; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013810:Therapeutic Equivalency; D014700:Verapamil / Q000097:blood* / Q000493:pharmacokinetics
chemical_list: D014700:Verapamil