Radioimmunoassay for Glyburide in Human Serum

Abstract

A radioimnunoassay (RIA) has been developed to measure nanogram amounts of drug-related materials in human serum, after oral administration of 1.25, 2.5, 3.75 or 5.0 mg glyburide, G, Micronase®, (Micronase® is the registered trademark of The Upjohn Company for 1-[[p-[2-(5-chloro-o-anisamido)ethyl]phenyl]-sulfonyl] 3-cyclohexylurea). Of the compounds tested, only the known hydroxy metabolites of G cross-reacted significantly. Using 20 μl specimens, containing 25.6 ng G/ml serum, the within-day and between-day coefficients of variation for the assay were 3.47% and 3.18%, respectively. Recoveries were quantitative (100.6%). In normal human volunteers, peak serum drug concentrations were observed at 4.3 ± 1.4 hrs (S.D., M = 32). After single oral doses