A Methodology for Quantitation of Dictamnine and Fraxinellone and its Application to Study Pharmacokinetics and Bioavailability in Rats Via Oral and Intravenous Administration

Abstract The pharmacological activities of dictamnine and fraxinellone have been well reported; however, only a few studies have focused on the pharmacokinetics and bioavailability of concomitant delivery of these drugs in vivo. To shed light on this neglected area, we developed a rapid and sensitive UPLC-MS/MS method that quantified the levels of dictamnine and fraxinellone simultaneously in rat plasma. This method was initiated by a one-step protein precipitation strategy to purify plasma samples collected from rats treated with either oral or intravenous administration of dictamnine and fraxinellone. The mobile phase contained acetonitrile and 0.1% formic acid at a steady flow rate of 0.6 mL/min. As a result, an excellent analyte peak resolution was achieved, and the entire process took only 3 min per sample. The results were indicative of the desired linearity (r2 ≥ 0.999), precision (RSD% was within 15%), accuracy (RE% was within 15%), recoveries (≥80.66 and 68.15% for dictamnine and fraxinellone, respectively) and matrix effects (≥94.66 and 91.37% for dictamnine and fraxinellone, respectively). Additionally, the detectable limits of these two compounds were both low even when they reached 5 ng/mL. Taken together, these findings contribute to a better understanding of the pharmacokinetics and bioavailability properties of concomitant delivery of dictamnine and fraxinellone.