RESUMO
Miltefosine (MFS) is the first effective oral drug for treatment of visceral, mucosal and cutaneous leishmaniasis. In this study, liquid chromatography coupled mass spectrometry (LC-MS/MS) method of MFS was validated in rat plasma and its practical utilization to pharmacokinetic studies in rats for the first time. A rapid, selective and sensitive LC-MS/MS method for MFS in rat plasma was linear over the calibration range of 1-500ng/mL. MFS and Phenacetin (internal standard) were separated on Phenomenex Luna 3µ HILIC 200A (150×4.6mm) column under isocratic condition using methanol: 0.1% formic acid in triple distilled water, 90:10 (v/v) mobile phase at a flow rate of 0.8mL/min. The total chromatographic run time was 4.0min. The intra- and inter-day assay accuracy was observed between 99.45-102.88% and 99.92-101.58%, respectively. The intra- and inter-day assay precision was observed between 2.68-5.54% and 2.35-5.94%, respectively. The validated assay was practically applied to determine the plasma concentrations after oral and intravenous administration of MFS to rats. After oral administration, MFS showed Cmax (3200.00±95.39ng/mL) was observed at 12.00h (tmax) and t1/2 was 102.36±16.65h. The absolute bioavailability of MFS was 60.33±2.32%.