Venlafaxine loaded chitosan NPs for brain targeting: Pharmacokinetic and pharmacodynamic evaluation

The purpose of the present investigation was to prepare venlafaxine (VLF) loaded chitosan nanoparticles (NPs) to enhance the uptake of VLF to brain via intranasal (i.n.) delivery. VLF loaded chitosan NPs were prepared and characterized for particle size, size distribution, zeta potential, encapsulation efficiency and in vitro drug release. In order to investigate the localization of chitosan NPs in brain and other organs qualitatively confocal laser scanning microscopy technique was carried out using rhodamine-123 (ROD-123) as marker. The levels of VLF in plasma and brain tissues were also determined, the brain/blood ratios of VLF for VLF (i.v.), VLF (i.n.), VLF chitosan NPs (i.n.) were 0.0293, 0.0700 and 0.1612, respectively, at 0.5 h, indicative of better brain uptake of VLF chitosan NPs. The higher drug transport efficiency (508.59) and direct transport percentage (80.34) of VLF chitosan NPs as compared to other formulations suggest its better efficacy in treatment of depression.