Abstract:Objective To investigate the pharmacokinetics and tissue distribution of leonurine oil/oil (O/O) microemulsion and leonurine suspension in mice. Methods High- performance liquid chromatography was used to measure the concentration of leonurine in the plasma and tissues of mice and to calculate pharmacokinetic parameters. Results Compared with leonurine suspension, leonurine (O/O) microemulsion had the average residence time in vivo increased by about 7 hours, and its relative bioavailability was 550.684%. The area under the time- concentration curve (0→∞) for leonurine (O/O) microemulsion in different tissues of mice increased to 3.626- 26.265 times compared with that for leonurine suspension. The drug targeting index of leonurine (O/O) microemulsion in the heart, lung, and brain was 1.044, 1.335, and 4.772, respectively. Conclusion The leonurine (O/O) emulsion has increased bioavailability and has a strong distribution in the brain.