Drug targeting to brain: a systematic approach to study the factors, parameters and approaches for prediction of permeability of drugs across BBB.

INTRODUCTION: Drug targeting to brain by circumventing the physiological barriers is a prerequisite for drugs acting on central nervous system (CNS) and therapeutic potential of many drugs can be improved by effectively targeting the drug(s) to brain. AREAS COVERED: Present review describes blood-brain barrier (BBB), drug transport mechanisms and factors affecting drug transportation across BBB along with in vitro BBB models; and the approaches for evaluation of permeability of drug across BBB. EXPERT OPINION: The development of a still awaited perfect in vitro model to mimic BBB is a challenging task. System biologist, network biologist and computational technologist should come together to integrate the role of transporters, physiological and pathophysiological complexity of BBB to replicate vascular properties of the brain microcapillaries as a suitable model to facilitate the high-throughput screening of CNS acting biomolecules.