Determination of manassantin B in rat plasma using a high performance liquid chromatography with fluorescence detection and its quantitative application to pharmacokinetic study

•A simple and sensitive analytical method of manassantin B in plasma was developed.•HPLC with fluorescence detector was adopted for its quantitative analysis.•Precision and accuracy values in all tests were within the acceptable ranges.•Developed method was successfully applied to pharmacokinetic study in rats.

A simple, sensitive, rapid, and reproducible analytical method of manassantin B in rat plasma by high performance liquid chromatography with fluorescence detection (HPLC-FL) was developed for its application to pharmacokinetic study in rats. Valsartan (VST) was used as an internal standard (IS) in this quantitative analytical method. Manassantin B and VST were extracted by simple and efficient protein precipitation method. Manassantin B was detected at 282/322 nm (excitation/emission) wavelengths using FL detector. The chromatographic separation was obtained with reverse phase C18 column and the mobile phase composed of potassium phosphate buffer containing 0.025% trifluoroacetic acid (pH 2.5; 5 mM) and acetonitrile including 0.025% trifluoroacetic acid (20:80, v/v) at 1.0 mL/min flow rate. The linearity was established at 25.0–10000 ng/mL and the lower limit of detection (LLOD) was 7 ng/mL. The intra- and inter-day accuracy and precision values of manassantin B were within ± 15% of the theroretical values and <9% from the nominal concentrations, respectively. Accuracy and precision values of manassantin B after stability tests were also within the acceptable ranges. Developed assay was also successfully applied to pharmacokinetic study after intravenous administration of manassantin B in rats.