DIRECTING DRUGS TO THE BRAIN: A MULTIFACETED PERSPECTIVE ON NASAL DELIVERY SYSTEMS

Abstract

The blood–brain barrier (BBB) poses a significant challenge in delivering therapeutic agents to the central nervous system (CNS), limiting the effectiveness of many pharmacological interventions. Nose-to-brain delivery has emerged as a promising, noninvasive strategy that enables direct transport of drugs from the nasal cavity to the brain, bypassing systemic circulation and the BBB. This review highlights the multifaceted aspects of intranasal drug delivery, including anatomical pathways (olfactory and trigeminal routes), physicochemical considerations of drugs, formulation strategies, and carrier-based systems such as nanoparticles, liposomes, and mucoadhesive gels. Advances in nanotechnology, bioadhesive polymers, and targeted delivery systems have further improved drug retention and brain bioavailability. Clinical applications span a wide range of CNS disorders, including Alzheimer’s disease, Parkinson’s disease, epilepsy, depression, and brain tumors. Despite its potential, challenges such as mucociliary clearance, limited drug volume capacity, and variability in patient anatomy remain. This review underscores the significance of noseto-brain drug delivery as a versatile and patient-friendly approach, paving the way for future innovations in CNS therapeutics.