Intranasal delivery of lipid nanoparticles: A ground-breaking approach for brain targeting

In the present scenario, various novel delivery systems are available for drug delivery to systemic circulation. So, to accomplish a greater therapeutic effect, the nature of the drug delivery is very important. This delivery is one of the innovative approaches where the drug is targeted to the brain through the nasal cavity. As we know, the human brain is the most crucial part of the body that controls various functions of our system. So, safely reaching the targeted site of the brain is necessary to achieve brain specificity. This delivery system helps us to tackle the problems that may arise in the other delivery system and helps the drug reach the brain without any difficulties. The major obstacles we faced during this delivery were the blood-brain barrier (BBB) and the brain-cerebrospinal fluid barrier. So, if we target the drug to the brain, then we have to overcome these challenges, and before that, we must have a clear understanding of the targeted site and the mechanism behind the drug targeting. Advancements in science and technology have helped discover many recent strategies and formulations available for intranasal delivery. The development of lipid nanoparticles is one of the primitive approaches for targeting any type of drug(hydrophilic/lipophilic) in the brain. So, the aim of this review mainly focused on the mechanism of intranasal delivery, the devices used, and some recent strategies like the development of lipid nanoparticles, surface-modified lipid nanocarriers, and nose-to-brain patches. This review article also includes a few FDA-approved formulations for nose-to-brain delivery and their regulatory aspects related to clinical trials and future perspectives.