A Quantitative LC-MS/MS Method for Determination of Liposomal Amphotericin B in Rat Plasma and Tissues and its Application to a Toxicokinetic and Tissue Distribution Study

Background: Among the existing antifungal drugs, Amphotericin B is the first drug in the treatment of systemic fungal infections. However, its large adverse reactions limit the clinical application and Liposome Amphotericin B resolves the problem. Objective: In the present study, a rapid, simple, sensitive and efficient method based on LCMS/ MS for determination of liposomal Amphotericin B in rat plasma and tissue samples using natamycin as the internal standard has been developed and validated. Methods: The analytical samples contain the plasma and various tissues disposed of by protein precipitation and determination of liposomal Amphotericin B by an LC-MS/MS. Chromatographic separation was achieved on a Poroshell 120 EC-C18 column (4.6 mm x 50 mm, 2.7 μm) with 10 mmol/L ammonium acetate in water-acetonitrile by gradient elution at a flow rate of 0.7 mL/min. The MS analysis was conducted in positive electrospray ionization with Multiple Reaction Monitoring (MRM). Results: The calibration curves of plasma and tissues showed good linear range from 50 to 10000 ng/mL. The analytical samples containing plasma and tissues were stable under different storage conditions and temperature. Conclusion: The developed LC-MS/MS method has been successfully applied to the studies of toxicokinetics and tissue distribution after intravenous injection of liposomal Amphotericin B to rats.