title: Determination of fexofenadine enantiomers in human plasma with high-performance liquid chromatography.
abstract: A simple and sensitive high-performance liquid chromatography (HPLC) method was developed as an assay for fexofenadine enantiomers in human plasma. Fexofenadine enantiomers were separated using a mobile phase of 0.5% KH(2)PO(4)-acetonitrile (65:35, v/v) on a Chiral CD-Ph column at a flow rate of 0.5 ml/min and measurement at 220 nm. Analysis required 400 microl of plasma and involved solid-phase extraction with an Oasis HLB cartridge, which gave recoveries for both enantiomers from 67.4 to 71.8%. The lower limit of quantification was 25 ng/ml for (R)- and (S)-fexofenadine. The linear range of this assay was between 25 and 625 ng/ml (regression line r(2)>0.993). Inter- and intra-day coefficients of variation were less than 13.6% and accuracies were within 8.8% over the linear range for both analytes. This method can be applied effectively to measure fexofenadine enantiomer concentrations in clinical samples.
authors.affiliation: Department of Pharmacy, Akita University Hospital, 1-1-1 Hondo, Akita 010-8543, Japan. m-miura@hos.akita-u.ac.jp
authors.forename: Masatomo
authors.initials: M
authors.lastname: Miura
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Uno
authors.forename: Tomonori
authors.initials: T
authors.lastname: Tateishi
authors.forename: Toshio
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000592:standards; D004355:Drug Stability; D039563:Histamine H1 Antagonists, Non-Sedating / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D006801:Humans; D016014:Linear Models; D015394:Molecular Structure; D010710:Phosphates / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012997:Solvents / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013237:Stereoisomerism; D016593:Terfenadine / Q000031:analogs & derivatives* / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics
chemical_list: D000097:Acetonitriles; D039563:Histamine H1 Antagonists, Non-Sedating; D010710:Phosphates; D017680:Potassium Compounds; D012997:Solvents; D016593:Terfenadine; C013216:potassium phosphate; C093230:fexofenadine; C032159:acetonitrile