TY - JOUR T1 - Simultaneous determination of a selective adenosine 2A agonist, BMS-068645, and its acid metabolite in human plasma by liquid chromatography-tandem mass spectrometry--evaluation of the esterase inhibitor, diisopropyl fluorophosphate, in the stabilization of a labile ester-containing drug. AU - Zeng,Jianing, AU - Onthank,David, AU - Crane,Paul, AU - Unger,Steve, AU - Zheng,Naiyu, AU - Pasas-Farmer,Stephanie, AU - Arnold,Mark, Y1 - 2007/01/13/ PY - 2006/09/28/received PY - 2006/12/22/revised PY - 2006/12/31/accepted PY - 2007/2/7/pubmed PY - 2007/8/2/medline PY - 2007/2/7/entrez SP - 77 EP - 84 JF - Journal of chromatography. B, Analytical technologies in the biomedical and life sciences JO - J Chromatogr B Analyt Technol Biomed Life Sci VL - 852 IS - 1-2 N2 - BMS-068645 is a selective adenosine 2A agonist that contains a methyl ester group which undergoes esterase hydrolysis to its acid metabolite. To permit accurate determinations of circulating BMS-068645 and its acid metabolite, blood samples must be rapidly stabilized at the time of collection. A sensitive, rapid and specific liquid chromatography-tandem mass spectrometry (LC/MS/MS) method for the simultaneous quantitation of BMS-068645 and its acid metabolite in human plasma has been developed and validated using diisopropyl fluorophosphate (DFP) as the esterase inhibitor to prevent BMS-068645 from converting to its acid metabolite. The D(5)-stable isotope labeled analogs of BMS-068645 and its metabolite were used as the internal standards (IS). Analytes and IS in plasma containing 20 mM DFP were acidified and extracted into methyl tert-butyl ether. The liquid-liquid extraction effectively eliminated the strong matrix effect caused by the esterase inhibitor. The chromatographic separation was achieved on a Waters Atlantis C18 column with a run time of 4 min. Detection was performed on a Sciex API 4000 with positive ion electrospray mode (ESI/MS/MS), monitoring the ion transitions m/z 487>314 and 473>300 for BMS-068645 and its acid metabolite, respectively. The method was validated over the range from 0.020 to 10.0 ng/mL for BMS-068645 and 0.050 to 10.0 ng/mL for its acid metabolite. Inter- and intra-run precision for the quality control samples during validation were less than 8.7% and 4.0%, respectively, for the two analytes. The assay accuracy was within +/-5.4% of the nominal values. The esterase inhibitor effectively stabilized BMS-068645 during blood collection and storage. Blood collection tubes containing DFP were easily prepared and used at the clinical sites and could be stored at -30 degrees C for 3 months. This method demonstrated adequate sensitivity, specificity, accuracy, precision, stability and ruggedness to support the analysis of human plasma samples in pharmacokinetic studies. SN - 1570-0232 UR - https://www.unboundmedicine.com/medline/citation/17280881/Simultaneous_determination_of_a_selective_adenosine_2A_agonist_BMS_068645_and_its_acid_metabolite_in_human_plasma_by_liquid_chromatography_tandem_mass_spectrometry__evaluation_of_the_esterase_inhibitor_diisopropyl_fluorophosphate_in_the_stabilization_of_a_labile_ester_containing_drug_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S1570-0232(07)00021-9 DB - PRIME DP - Unbound Medicine ER -