title: Hydrophilic interaction chromatography/tandem mass spectrometry for the simultaneous determination of three polar non-structurally related compounds, imipenem, cilastatin and an investigational beta-lactamase inhibitor, MK-4698, in biological matrices.
abstract: A method coupling hydrophilic interaction chromatography (HILIC) with tandem mass spectrometry (MS/MS) has been developed for the simultaneous determination of three polar non-structurally related compounds--a carbapenem antibiotic, imipenem (IMP), a renal dehydropeptidase inhibitor, cilastatin (CIL), and an investigational beta-lactamase inhibitor, MK-4698 (BLI), in rat plasma, monkey plasma and mouse blood. The analytes were extracted through protein precipitation, chromatographed on a Waters Atlantis HILIC column, and detected on a Sciex API4000 mass spectrometer using a Turbo-Ion Spray ion source in positive ionization mode following multiple-reaction monitoring (MRM). The assay dynamic range was 0.1-100 microg/mL for IMP, CIL and BLI, respectively, using a total of 20-25 microL biologic samples, and the total HPLC/MS/MS run time was 4 min/injection. The assay was found to be sensitive, selective and reproducible. The challenges, namely, sample stability, blood sample processing, matrix effect in monkey study samples, and dilution re-assays for the limited mouse blood samples, are resolved and discussed. This technique allowed rapid analysis of polar compounds in biologic matrixes with satisfactory chromatographic retention and increased throughput.
authors.affiliation: Merck Research Laboratories, Department of Drug Metabolism and Pharmacokinetics, 770 Sumneytown Pike, WP75B-300, West Point, PA 19486, USA. yang_xu@merck.com
authors.forename: Yang
authors.initials: Y
authors.lastname: Xu
authors.forename: Wei
authors.initials: W
authors.lastname: Xie
authors.forename: Cynthia M
authors.initials: CM
authors.lastname: Miller-Stein
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Woolf
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000097:blood / Q000737:chemistry; D002845:Chromatography / Q000379:methods*; D015377:Cilastatin / Q000097:blood / Q000737:chemistry*; D004791:Enzyme Inhibitors / Q000097:blood / Q000737:chemistry*; D000882:Haplorhini; D015378:Imipenem / Q000097:blood / Q000737:chemistry*; D051379:Mice; D051381:Rats; D053719:Tandem Mass Spectrometry / Q000379:methods*; D065093:beta-Lactamase Inhibitors
chemical_list: D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D065093:beta-Lactamase Inhibitors; D015377:Cilastatin; D015378:Imipenem