A high-performance liquid chromatographic assay for the determination of amphotericin B serum concentrations after the administration of AmBisome, a liposomal amphotericin B formulation

A sensitive and selective high-performance liquid chromatographic (HPLC) method has been developed for the determination of amphotericin B in human serum. After methanol deproteinization, amphotericin B and 3-nitrophenol (internal standard) are separated by reversed-phase chromatography and detected by ultraviolet absorbance. The analysis of human serum after the standard addition of amphotericin B (0.05-200.0 mu g/mL) demonstrated excellent precision and accuracy over a five-day period. 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 regimens (2.5-5.0 mg/kg) is 0.5-200 mu g/mL (curve 2). The intraday and interday 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/mL. The intraday and interday coefficients of variation for standard curve 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 present in blank serums or serum samples spiked with fifteen potential co-administrated drugs with Amphotericin B treatment. The method was used to quantitate serum concentrations of amphotericin B in patients after the administration of AmBisome, a liposomal formulation of amphotericin B.