Abstract
Brain, the centre of the nervous system and an integral part the body, is protected by two anatomical and physiological barriers-Blood-Brain Barrier (BBB) and Blood-Cerebrospinal Fluid Barrier (BCSFB). Blood-Brain Barrier is a very complex and highly organized multicellular structure that shields the brain from harmful substances and invading organisms from the bloodstream and thus offering protection against various brain diseases and injuries. However, it also impede the effective delivery of drug to the brain, thus, preventing treatment of numerous neurological disorders. Even though various traditional approaches such as Intra-Cerebro-Ventricular (ICV) injection, use of implants, disruption of BBB and use of prodrugs have achieved some success in overcoming these barriers, researchers are continuously working for promising alternatives for improved brain drug delivery. Recent breakthroughs in the field of nanotechnology provide an appropriate solution to problems associated with these delivery approaches and thus can be effectively used to treat a wide variety of brain diseases. Thus, nanotechnology promises to bring a great future to the individuals with various brain disorders. This review provides a brief overview of various brain drug delivery approaches along with limitations. In addition, the significance of nanoparticles as drug carrier systems for effective brain specific drug delivery has been highlighted. To show the complexity of the problems to be overcome for improved brain drug delivery, a concise intercellular classification of the BBB along with general transport routes across it is also included.