title: HPLC method with solid-phase extraction for determination of (R)- and (S)-ketoprofen in plasma without caffeine interference: application to pharmacokinetic studies in rats.
abstract: A fast and reproducible high-performance liquid chromatography method has been developed for the determination of (R)- and (S)-ketoprofen. Ketoprofen enantiomers were determined in plasma samples (50 µL), after solid-phase extraction, using diclofenac as internal standard. Analyses were performed on a (S, S)-Whelk-O 1 stainless steel column (5 µm, 250 × 4.6 mm) using hexane-ethanol-acetic acid (93:7:0.5, v/v/v) as the mobile phase and detection at 254 nm. The method was selective for ketoprofen enantiomers in the presence of caffeine and endogenous plasma compounds. Standard curves were linear (R(2) > 0.999) over the concentration range of 0.25-12.50 and 0.25 µg/mL was taken as the limit of quantification. The intra- and interday precision (relative standard deviation) values were <15.0% and the accuracy (relative error) was within ±12.0% at 1.0, 5.0 and 10.0 µg/mL. Enantiomer recoveries yielded 100.0 ± 15%. No significant differences were determined in plasma samples stored at room temperature for 24.0 h, after two freeze-thaw cycles, and between 0 and 4 weeks at -20°C (P > 0.05). The validated method was successfully applied in determination of (S)-ketoprofen in Wistar rats after oral administration of 3.2 mg/kg of (S)-ketoprofen alone or 3.2 mg/kg of (S)-ketoprofen + 17.8 mg/kg of caffeine.
authors.affiliation: Departamento Sistemas Biológicos UAM-Xochimilco, Calzada del Hueso 1100, Colonia Villa Quietud, México, D.F., CP 04960, México Departamento Farmacobiología, Cinvestav-Sede Sur, Calzada de los Tenorios 235, Colonia Granjas Coapa, México, D.F., CP 14330, México.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: López-Muñoz
authors.affiliation: Departamento Sistemas Biológicos UAM-Xochimilco, Calzada del Hueso 1100, Colonia Villa Quietud, México, D.F., CP 04960, México.
authors.forename: Nancy
authors.initials: N
authors.lastname: Vara Gama
authors.affiliation: Departamento Sistemas Biológicos UAM-Xochimilco, Calzada del Hueso 1100, Colonia Villa Quietud, México, D.F., CP 04960, México.
authors.forename: Olivia
authors.initials: O
authors.lastname: Soria-Arteche
authors.affiliation: Departamento Sistemas Biológicos UAM-Xochimilco, Calzada del Hueso 1100, Colonia Villa Quietud, México, D.F., CP 04960, México.
authors.forename: Marcela
authors.initials: M
authors.lastname: Hurtado y de la Peña
authors.affiliation: Departamento Sistemas Biológicos UAM-Xochimilco, Calzada del Hueso 1100, Colonia Villa Quietud, México, D.F., CP 04960, México.
authors.forename: Adriana Miriam
authors.initials: AM
authors.lastname: Domínguez-Ramírez
authors.affiliation: Departamento Sistemas Biológicos UAM-Xochimilco, Calzada del Hueso 1100, Colonia Villa Quietud, México, D.F., CP 04960, México rmlopez@correo.xoc.uam.mx.
authors.forename: José Raúl
authors.initials: JR
authors.lastname: Medina López
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002110:Caffeine / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004347:Drug Interactions; D004355:Drug Stability; D007660:Ketoprofen / Q000008:administration & dosage / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*
chemical_list: D002110:Caffeine; D007660:Ketoprofen