ABSTRACT
274Drug delivery to the brain is one of the most challenging areas of research in the pharmaceutical field not only due to the blood–brain barrier (BBB) but also for the blood–cerebro-spinal fluid barrier. Being a delicate organ, the brain has a complex physiological structure and also a complicated mechanism of action. Tight junctions between the cerebral endothelial cells at the blood–brain interface restrict the entry of 98% of small molecule drugs and 100% of large molecule drugs, specially hydrophilic substances to maintain the homeostasis of the brain. This drug delivery challenge is an obstacle in the treatment of central nervous system (CNS) disorders such as epilepsy, Alzheimer’s disease, Parkinson’s disease, and brain tumors, etc. Therefore, to deliver drugs to the brain we must overcome these problems. Researchers have found some solutions such as drug modification, and new delivery system strategies like nanocarriers are used to deliver drugs to the brain. These nanocarriers are advantageous over conventional delivery systems because they not only overcome the limitation properties of the drug or the delivery system to cross the BBB but also provide some extra opportunities, such as sustained release and dose reduction of the drug as well as a reduction of toxicity, and protection of the drug from chemical or enzymatic degradation. In light of these many advantages, nanotechnology is a main focus in every field of research now-a-days. Nanotechnology-based drug delivery systems are a more effective and more promising strategy because of their controlled release or site specific action, particularly to deliver drugs to the brain. So, this chapter enlightens the nanotechnology-based delivery approach to the brain, which may help researchers, academia, and industrialists.
