Pharmacokinetic study of three different formulations of l‐tetrahydropalmatine in brain tissues of rats

l ‐Tetrahydropalmatine ( l‐ THP), an active alkaloid compound isolated from Rhizoma Corydalis‐yanhusuo, has been reported to possess biological activity for treating cocaine use. To enhance both oral bioavailability and brain penetration, three formulations of l ‐THP suspension, mixture of l ‐THP–puerarin and self‐microemulsifying drug delivery systems (SMEDDS) were prepared. A sensitive and reliable ultra‐high‐performance liquid chromatography...