A HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ASSAY FOR THE DETERMINATIONOF AMPHOTERICIN-B SERUM CONCENTRATIONS AFTER THE ADMINISTRATION OF AMBISOME, A LIPOSOMAL AMPHOTERICIN-B FORMULATION

A sensitive and selective high-performance liquid chromatographic (HPL C) method has been developed for the determination of amphotericin B i n human serum. After methanol deproteinization, amphotericin B and 3-n itrophenol (internal standard) are separated by reversed-phase chromat ography and detected by ultraviolet absorbance. The analysis of human serum after the standard addition of amphotericin B (0.05-200.0 mu g/m L) demonstrated excellent precision and accuracy over a five-day perio d. The HPLC assay uses two standard curve ranges. The high sensitivity curve range for low AmBisome dosage (1.0 mg/kg) is 0.05-20.0 mu g/mL (curve 1), and the second curve range for the higher AmBisome dose reg imens (2.5-5.0 mg/kg) is 0.5-200 mu g/mL (curve 2). The intraday and i nterday coefficients of variations for standard curve 1 were 0.5-4.6% and 3.0-11.5%, respectively. The limit of quantitation was 0.05 mu g/m L. The intraday and interday coefficients of variation for standard cu rve 2 were 2.0-3.6 and 6.9-10.1, respectively. No interfering peak at the retention time for Amphotericin B and the internal standard were p resent in blank serums or serum samples spiked with fifteen potential co-administrated drugs with Amphotericin B treatment. The method was u sed to quantitate serum concentrations of amphotericin B in patients a fter the administration of AmBisome, a liposomal formulation of amphot ericin B.