Summary
Nasal drug delivery has evolved since the 1950s from locally administered treatments to systemically acting therapies for depression, seizures, vaccines and more. There has also been a transition from small molecules to biomolecules like peptides, mAbs and oligonucleotides. The nasal cavity enables systemic absorption through vascularization, reduced enzymatic activity and no hepatic first pass metabolism. The nasal route enables rescue medications like epinephrine and glucagon as well as durable treatments such a sumatriptan and zavegepant for migraine headaches.
A key to advancing administration through the nose is the transport mechanisms associated with olfactory, lymph and immune cells. Animal studies and in vitro studies are beginning to determine potential drug pathways via perineuronal and perivascular routes from the nose into the brain. As research begins to unlock these mechanisms, nasal formulations can be optimized for CNS indications. Nasal vaccines are entering a new era with the first self-administered influenza vaccine. This development may transform public access and the future for nasal vaccines. Targeting the cervical lymph nodes via the nasal cavity may also become a transformative route for nasal drug delivery. The future continues to evolve with exciting new opportunities.