Oleanolic acid is a poorly water-soluble drug with low oral bioavailability. A self-
microemulsifying drug delivery system (SMEDDS) has been developed to enhance the
solubility and oral bioavailability of oleanolic acid. The formulation design was optimized by
solubility assay, compatibility tests, and pseudoternary phase diagrams. The morphology,
droplet size distribution, zeta potential, viscosity, electrical conductivity, and refractive index
of a SMEDDS loaded with oleanolic acid were studied in detail. Compared with oleanolic …

Dipyridamole shows poor and variable bioavailability after oral administration due to
pHdependent solubility, low biomembrane permeability as well as being a substrate of P-
glycoprotein. In order to improve the oral absorption of dipyridamole, a self-microemulsifying
drug delivery system (SMEDDS) for dipyridamole was prepared and evaluated in vitro and
in vivo. The optimum formulation was 18% oleic acid, 12% Labrafac lipophile WL 1349, 42%
Solutol HS 15 and 28% isopropyl alcohol. It was found that the performance of self …