title: Determination of an echinocandin, MK-0991, in mammalian plasma by radioimmunoassay.
abstract: A quantitative method based on radioimmunoassay for the determination of the antifungal agent, CANCIDAS (MK-0991) has been developed and validated. The immunogen was prepared by coupling MK-0991 to bovine serum albumin through a two-step reaction with difluorodinitrobenzene. An antiserum specific to MK-0991 was selected for RIA. The assay was based on the competitive immunoassay principle in which the drug competes with iodinated drug for a limited quantity of specific antibody. The bound tracer was separated via goat anti-rabbit globulin. The assay demonstrates good accuracy and reproducibility at plasma concentration down to 10 ng/ml. The specificity of the RIA method was confirmed by cross-validating against an established HPLC method.
authors.affiliation: Department of Drug Metabolism, WP75A-203, Merck Research Laboratories, West Point, PA 19486, USA. alyuan@merck.com
authors.forename: A S
authors.initials: AS
authors.lastname: Yuan
authors.forename: D
authors.initials: D
authors.lastname: Cylc
authors.forename: J Y
authors.initials: JY
authors.lastname: Hsieh
authors.forename: B K
authors.initials: BK
authors.lastname: Matuszewski
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000097:blood* / Q000378:metabolism; D000077336:Caspofungin; D054714:Echinocandins; D055666:Lipopeptides; D010455:Peptides; D010456:Peptides, Cyclic; D011817:Rabbits; D011863:Radioimmunoassay / Q000379:methods*; D011869:Radioligand Assay; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012710:Serum Albumin, Bovine / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D054714:Echinocandins; D055666:Lipopeptides; D010455:Peptides; D010456:Peptides, Cyclic; D012710:Serum Albumin, Bovine; D000077336:Caspofungin