Background: Brain is a delicate organ, separated from general circulation and is characterized
by the presence of relatively impermeable Blood Brain Barrier (BBB). The BBB maintains homeostasis
in the brain thus restricting the entrance of foreign bodies and several molecules from
reaching the brain. As a result several promising molecules do not reach the target site and fail to produce
in vivo response. Nevertheless, lipid nanoparticles are taken up readily by the brain because of
their lipophilic nature. The bioacceptable and biodegradable nature of lipid nanoparticles makes them
less toxic and suited for brain targeting.
Objective: In the present review the BBB, mechanism of transport across the BBB, strategies to bypass
the blood-brain barrier have been presented. The aptness of lipid nanoparticles for brain targeting
has been highlighted. The proposed mechanism of uptake of the lipid nanoparticles, methods of prolonging
the plasma retention and various methods of preparation for formulation of effective delivery
systems for brain targeting have been included and dealt in this review.
Conclusion: Lipid based formulations can be designated as the current and future generation of drug
delivery systems as these possess tremendous potential to bypass BBB and reach the target site due to
their small size and ability to dodge the reticular endothelial system. However, these nanostructures
need to be investigated intensively to successfully reach the clinical trials stage.