title: High-performance liquid chromatographic analysis of amoxicillin in human and chinchilla plasma, middle ear fluid and whole blood.
abstract: We extended the application of a sensitive high-performance liquid chromatography assay of amoxicillin developed in this laboratory for human plasma and middle ear fluid (MEF) to other sample matrices including chinchilla plasma or MEF and human and chinchilla whole blood with minor modification and validated the limit of quantitation at 0.25 microg/ml with a 50-microl sample size for human and chinchilla plasmas or MEFs. Amoxicillin and cefadroxil, the internal standard, were extracted from 50 microl of the samples with Bond Elut C18 cartridges. The extract was analyzed on a Keystone MOS Hypersil-1 (C8) column with UV detection at 210 nm. The mobile phase was 6% acetonitrile in 5 mM phosphate buffer, pH 6.5 and 5 mM tetrabutylammonium. The within-day coefficients of variation were 2.7-9.9 (n=4) and 1.7-7.2% (n=3) for chinchilla plasma and MEF samples, respectively; 2.8-8.1% (n=3) and 2.9-4.7% (n=3) for human and chinchilla whole blood, respectively. An alternative mobile phase composition for chinchilla plasma and MEF samples reduced the analysis time significantly.
authors.affiliation: College of Pharmacy and School of Medicine, Department of Pharmacy Practice, University of Minnesota, Minneapolis 55455, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Yuan
authors.forename: H Q
authors.initials: HQ
authors.lastname: Russlie
authors.forename: D M
authors.initials: DM
authors.lastname: Canafax
mesh_terms: D000658:Amoxicillin / Q000097:blood / Q000378:metabolism*; D000818:Animals; D001826:Body Fluids / Q000378:metabolism*; D002682:Chinchilla; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004432:Ear, Middle / Q000378:metabolism*; D006801:Humans; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000658:Amoxicillin