DETERMINATION OF SINEFUNGIN IN RAT PLASMA BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A reversed-phase high-performance liquid chromatographic method for th e determination of sinefungin, a new antiprotozoal drug, in rat plasma has been developed and validated. Sample preparation was performed at 4 degrees C by deproteinization with acetonitrile. Vidarabine was use d as an internal standard. Both sinefungin and vidarabine were separat ed on a C-18 column with a mobile phase of ammonium dihydrogenphosphat e-acetonitrile (95:5, v/v) and detected by ultraviolet absorbance at 2 60 nm. Recoveries of sinefungin from plasma were 75 +/- 3.2% and 81 +/ - 4.8% following dosage at concentrations of 10 mu g/ml and 30 mu g/ml , respectively. Using 250 mu l of rat plasma, the limit of quantitatio n was 1 mu g/ml sinefungin, and the assay was linear from 1 to 30 mu g /ml. This method appears sensitive enough to be used in further pharma cokinetic studies of sinefungin in animal models.