title: Column-switching high-pressure liquid chromatographic method for the determination of a new carbapenem antibiotic, L-739,428, in rat and monkey plasma.
abstract: A column-switching HPLC method for determination of a new carbapenem antibiotic, L-739,428 (I), was developed that allowed direct injection of rat and monkey plasma. Following dilution with a pH 6.5 buffer, samples were injected without further cleanup into an extraction column dry-packed with 10-microns particle size Maxsil C18 reversed-phase adsorbent. Endogenous plasma components were washed to waste for 6 min with a weak mobile phase of 0.025 M sodium phosphate, 0.005 M hexanesulfonate (pH 6.5). Compound I, retained on the extraction column, was then backflushed with a mobile phase which consisted of a mixture of the preceding buffer-ion pair solution and acetonitrile (96:4, v/v) into a Partisphere C18 analytical column and detected by ultraviolet absorption at 299 nm. Chromatographic retention time was 11.5 min. Stability of I in plasma was maximized by use of a refrigerated autosampler which maintained plasma at 5 degrees C until analyzed. The limit of quantification was 0.1 microgram/ml using the equivalent of 75 microliters plasma.
authors.affiliation: Department of Drug Metabolism, Merck Research Laboratories, West Point, PA 19486.
authors.forename: B K
authors.initials: BK
authors.lastname: Wong
authors.forename: P J
authors.initials: PJ
authors.lastname: Bruhin
authors.forename: J H
authors.initials: JH
authors.lastname: Lin
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000097:blood* / Q000493:pharmacokinetics; D015780:Carbapenems / Q000097:blood* / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid; D006207:Half-Life; D007275:Injections, Intravenous; D008253:Macaca mulatta; D051381:Rats
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; C085890:BO 2727