Quantitation of the anti-inflammatory agent fenbufen and its metabolites in human serum and urine using high-pressure liquid chromatography.

Specific procedures are described for the determination of fenbufen and its metabolites in serum and urine using high-pressure liquid chromatography. Serum or urine extracts were chromatographed on a bounded reversed-phase partitioning column. The sensitivity of the assay for fenbufen was 0.5 microgram/ml in serum with 2-ml samples and 1.0 microgram/ml in urine with 1-ml samples. The procedures are suitable for bioavailability and pharmacokinetic studies.