Abstract
Context: Brain disorders remain the world's leading cause of disability, and account for more hospitalizations and prolonged care than almost all other diseases combined. The majority of drugs, proteins and peptides do not readily permeate into brain due to the presence of the blood-brain barrier (BBB), thus impeding treatment of these conditions.Objective: Attention has turned to developing novel and effective delivery systems to provide good bioavailability in the brain.Methods: Intranasal administration is a non-invasive method of drug delivery that may bypass the BBB, allowing therapeutic substances direct access to the brain. However, intranasal administration produces quite low drug concentrations in the brain due limited nasal mucosal permeability and the harsh nasal cavity environment. Pre-clinical studies using encapsulation of drugs in nanoparticulate systems improved the nose to brain targeting and bioavailability in brain. However, the toxic effects of nanoparticles on brain function are unknown.Result and conclusion: This review highlights the understanding of several brain diseases and the important pathophysiological mechanisms involved. The review discusses the role of nanotherapeutics in treating brain disorders via nose to brain delivery, the mechanisms of drug absorption across nasal mucosa to the brain, strategies to overcome the blood brain barrier, nanoformulation strategies for enhanced brain targeting via nasal route and neurotoxicity issues of nanoparticles.