Olanzapine Loaded Cationic Solid Lipid Nanoparticles for Improved Oral Bioavailability

Olanzapine, a lipophilic antipsychotic drug, has poor oral bioavailability due to hepatic first-pass metabolism. Solid Lipid Nanoparticles (SLNs) of Olanzapine were developed using lipids (Stearic acid and Glyceryl monostearate), soy lecithin, poloxamer 188 and charge modifier stearyl amine by microemulsion technique. The aim of this research was to find out whether the bioavailability of olanzapine can be improved by administering olanzapine SLN orally to Wistar rats. Area under curve was increased (up to 4-fold) and clearance was decreased when olanzapine entrapped in SLNs with stearylamine were administered orally compared with that of olanzapine suspension. The enhanced relative bioavailability by the SLNs formulation might be attributed to avoidance of first-pass hepatic metabolism by intestinal lymphatic transport, direct uptake of nanoparticles through the GI tract, increased permeability by surfactants, and decreased degradation and clearance. These results indicate that olanzapine can be loaded into solid lipid nanoparticles for improvement of its oral bioavailability.