Abstract

The major obstacle in the development of centrally active therapeutics is the lipoidal blood-brain barrier. While a variety of systems to transport compounds into the central nervous system have been designed. The current challenge is to develop drug delivery strategies that will allow the passage of drug molecules through the blood-brain barrier in a safe and effective manner. The invasive approach involves the blood-brain barrier disruption either by osmotically or by using biologically active agents. The above strategies are primarily aimed at short-term application in the treatment regimens of malignant brain tumours while chronic degenerative disorders will require long term application of the therapeutic agent. Owing to this fact non-invasive approach for drug delivery to brain via the systemic route have been developed. Physiological strategy has been to conjugate the therapeutic drug with a protein or a vector or a monoclonal antibody that gains access to the brain by receptor mediated transcytosis. The uses of the drug delivery devices such as liposomes and nanoparticles enhance the penetration of several drugs across the brain. This review will provide an insight into some of the strategies developed to enhance drug delivery across the blood-brain barrier.