Leonurine (LE) has been found to have therapeutic efficacy in cerebral thrombosis, but its poor solubility in water leads to very low bioavailability. In this article, a leonurine O/O microemulsion (LE-ME) was prepared and investigated for its in vivo pharmacokinetic behavior and bioavailability in the mouse body using an aqueous suspension of leonurine (LE-SWW) for the control group. A simple, sensitive and specific method, HPLC-MS/MS, was developed for detection of the LE content in mouse plasma using n-benzoyl-L-arginine ethyl ester as an internal standard. The results demonstrated that the C max of LE-ME was 2.46-fold higher than that of the suspension following oral administration. The absolute bioavailability was 10.95 %, while that of the suspension was only 1.78 %. The T 1/2β and MRT of LE-ME were 3.04- and 4.19-fold those of the suspension, respectively. In addition, following intramuscular administration of LE-ME, the absolute bioavailability was 37.45 %. The results indicated that LE-ME is a promising drug-delivery system to enhance the absorption and bioavailability of LE.
Keywords: Bioavailability; Leonurine; Microemulsion; Pharmacokinetic.