Neurodegenerative diseases are a significant cause of mortality worldwide, and the blood-brain barrier (BBB) poses a significant challenge for drug delivery. An intranasal route is a prominent approach among the various methods to bypass the BBB. There are different pathways involved in intranasal drug delivery. The drawbacks of this method include mucociliary clearance, enzymatic degradation and poor drug permeation. Novel nanoformulations and intranasal drug-delivery devices offer promising solutions to overcome these challenges. Nanoformulations include polymeric nanoparticles, lipid-based nanoparticles, microspheres, liposomes and noisomes. Additionally, intranasal devices could be utilized to enhance drug-delivery efficacy. Therefore, intranasal drug-delivery systems show potential for treating neurodegenerative diseases through trigeminal or olfactory pathways, which can significantly improve patient outcomes.
Keywords: blood–brain barrier; drug-delivery system; intranasal; nanoparticle; neurodegenerative.
Neurodegenerative diseases cause severe illness worldwide, over a sixth of the world's population suffer from these diseases in which 10–15% of the world's population lose their life. The presence of the blood–brain barrier (BBB) is one of the major drawbacks for the treatment. There are many ways to bypass the BBB, the intranasal route was found to be prominent among all routes. The drug is transported across epithelial cells by passive diffusion. Drawbacks, adverse reactions and physicochemical properties of the drug affect drug availability in the brain. These drawbacks can be solved by using novel nano formulations and intranasal drug-delivery devices. Nano formulations deliver drugs with negligible disadvantages; several nano formulations suitable for nose-to-brain targeting include polymeric nanoparticles, lipid-based nanoparticles, microspheres, liposomes and niosomes. Delivery devices such as atomizers, nebulizers, pressurized olfactory devices metered-dose spray pumps and pressurized metered dose inhaler systems, dry powder inhalers, and powder devices have been used to deliver drugs to the brain through the intranasal route. The intranasal drug-delivery system could be a promising approach to treat neurodegenerative diseases, which could save the lives of a large patient population.