Determination of an echinocandin, MK-0991, in mammalian plasma by radioimmunoassay.
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.
Yuan
A S
AS
Department of Drug Metabolism, WP75A-203, Merck Research Laboratories, West Point, PA 19486, USA. alyuan@merck.com
Cylc
D
D
Hsieh
J Y
JY
Matuszewski
B K
BK
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
D000900:Anti-Bacterial Agents; D054714:Echinocandins; D055666:Lipopeptides; D010455:Peptides; D010456:Peptides, Cyclic; D012710:Serum Albumin, Bovine; D000077336:Caspofungin