Development of a Fast and Highly Sensitive UPLC–MS/MS Technique for Simultaneous Estimation of Artemether and Dihydroartemisinin with its Application to Pharmacokinetic and Biodistribution Studies

Abstract

Background: Artemether (ART) has been recognized as a potent and rapidly acting antimalarial agent metabolized by cytochrome P450 isoenzyme 3A4 into a more active form dihydroartemisinin (DHA). Hence, it was required to study the pharmacokinetics and biodistribution of ART and DHA for the optimization of dose. Objectives: The current research aims to develop an ultra-performance liquid chromatographytandem mass spectrometry (UPLC-MS/MS) technique with high sensitivity for quantification of ART and DHA simultaneous in the biological fluid. Methods: An isocratic elution mode was applied for delivery of mobile phase (A) ammonium acetate (2mM) in UPLC grade water and (B) acetonitrile (20:80, v/v) comprising 0.1% v/v formic acid in each solvent system with the rate of flow maintained at 400 μL/min. For analyte detection and parent to daughter ion transition tracking, multiple reaction monitoring system was adopted. Artemisinin was selected as the internal standard (IS) for its structural similarity with the analytes. Results: The linearity range of the calibration curve was between 0.5-200 ng/mL. The regression equation indicated r2 = 0.996 for ART and r2 = 0.997 for DHA. Precision and accuracy set in terms of relative error (RE%: ±15) and relative standard deviation (RSD%: ±15) expressed in percentage were within the acceptability range. The % recoveries were within the acceptable limit (90–110%). The detection and quantification limits of the analyte were 0.2 ng/mL and 0.5 ng/mL, respectively. Conclusion: The method demonstrated a useful technique for quantification of ART and DHA for evaluating the pharmacokinetics and biodistribution studies in rat plasma following orally administered nanoformulation.