High-pressure liquid chromatographic assay for griseofulvin in plasma.

A high-pressure liquid chromatographic procedure was developed for griseofulvin assay in human plasma. The method utilized warfarin as an internal standard and easily quantitated griseofulvin plasma levels as low as 0.10 micrograms/ml. The method was compared to two fluorometric assay methods and was more specific for griseofulvin. Assay of 6-demethylgriseofulvin isolated from human urine demonstrated that this material was not responsible for the interferences apparent in the fluorometric procedures.