BRAIN DRUG DELIVERY SYSTEM: A COMPREHENSIVE REVIEW ON RECENT EXPERIMENTAL AND CLINICAL FINDINGS

The blood-brain barrier (BBB) denies many therapeutic agents access to brain tumors and other diseases of the central nervous system (CNS). Despite remarkable advances in our understanding of the mechanisms involved in the development of the brain diseases and the actions of neuroactive agents, drug delivery to the brain remains a challenge. For more than 20 years, extensive efforts have been made to enhance delivery of therapeutic molecules across vascular barriers of the CNS. BBB allows a selective entry of nutrients and minerals across it and limits the entry of foreign substances like drugs as well as neuropharmaceutical agents. This makes the CNS treatment ineffective. The conventional drug delivery systems which release drug into general circulation fail to deliver drugs effectively to brain and is therefore not very useful in treating certain diseases that affect CNS including Alzheimer's disease, dementia, Parkinson's disease, mood disorder, AIDS, viral and bacterial meningitis. The current challenge is to develop drug delivery strategies that will allow the passage of drug molecules through the BBB in a safe and effective manner. The present review enlightens recent experimental and clinical findings in brain drug targeting that would give an insight to the researchers, academia and industrialists.