Assay methodology for quantification of the ester and ether glucuronide conjugates of diflunisal in human urine.
Diflunisal is a salicylate derivative with analgesic and anti-inflammatory properties. It is excreted in the urine as an ether glucuronide, a 1-O-acyl glucuronide and as unchanged drug. The 1-O-acyl glucuronide rearranges to isomeric esters of glucuronic acid under neutral to alkaline pH conditions. The development of a urine assay for the conjugates enables the elucidation of diflunisal non-linear pharmacokinetics. The assay quantitates the ether and ester glucuronides and free diflunisal in urine at 0.5-1.0 micrograms/ml. Analysis of the glucuronides does not require authentic standards.
D002851:Chromatography, High Pressure Liquid; D004061:Diflunisal / Q000031:analogs & derivatives / Q000652:urine*; D004355:Drug Stability; D006801:Humans; D006863:Hydrogen-Ion Concentration; D012459:Salicylates / Q000652:urine*; D012997:Solvents; D013056:Spectrophotometry, Ultraviolet
D012459:Salicylates; D012997:Solvents; C041945:diflunisal glucuronide ether; C041944:diflunisal glucuronide ester; D004061:Diflunisal