ABSTRACT
A majority of CNS drugs and brain drug delivery systems are administered systemically, most likely via intravenous (i.v.) injection because of the ease of application and avoidance of the fi rst pass effect (Sarin 2009). Following systemic administration, nanoparticles can follow either receptormediated transcytosis (RMT) or adsorptive-mediated transcytosis (AMT) to get into the brain. Intranasal drug administration has been investigated recently as an alternative to i.v. administration due to the large surface area available for drug absorption, porous endothelial membrane, high blood fl ow, the avoidance of drug loss in fi rst pass metabolism and mainly because it allows direct access of drugs from the nasal cavity to the brain via the olfactory epithelium by circumventing the BBB (Yang 2010). This route offers a new means for the long-term non-invasive management of chronic neurological disorders.
