A recent study in Experimental & Molecular Medicine analyzed a wide range of scientific breakthroughs to explore how medicines can get past the BBB and be delivered directly to the brain.

The nose seemed to offer an almost perfect back door to the brain. It is a fast, needle-free route that could bypass the blood-brain barrier altogether while also escaping the liver’s first round of drug breakdown. However, the nose is highly efficient at clearing or destroying foreign substances, leaving very little time for drugs to be absorbed before they are cleared out.

They found that advanced delivery systems may give drug molecules enough protection to survive the journey through the nose, using three possible strategies. Nanoparticles could give drugs a protective coat that helps them cling to mucus, carry their cargo safely and reach smell-related tissue.