DETERMINATION OF A CYCLIC HEXAPEPTIDE (L-743-872), A NOVEL PNEUMOCANDIN ANTIFUNGAL AGENT IN HUMAN PLASMA AND URINE BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH FLUORESCENCE DETECTION

A method based on high-performance liquid chromatography (HPLC) with f luorescence detection for the determination of a novel peptide antifun gal agent, L-743872 (I), in human plasma and urine is presented. Drug and internal standard were extracted from plasma and urine using did s olid-phase extraction columns and selectively eluted using a solution of trifluroacetic acid and ammonium hydroxide in methanol. Chromatogra phy was performed on a wide pore C8 column and detection was by fluore scence. Loss of drug from urine due to adsorption to plastic surfaces was prevented by the addition of bovine serum albumin (0.5% final conc entration), The range of the standard line was 10 to 1000 ng/ml for bo th matrices. The recovery of drug from plasma and urine was 76% and 84 %, respectively. The assay was used to measure drug concentrations in human plasma and urine after the administration of intravenous (IV) do ses of I. (C) 1997 Elsevier Science B.V.