NOSE TO BRAIN DRUG DELIVERY SYSTEM: A REVIEW

Nose-to-brain drug delivery has emerged as a promising noninvasive strategy to bypass the blood–brain barrier (BBB), enabling rapid and targeted transport of therapeutic agents directly to the central nervous system (CNS). This route utilizes the unique anatomical and physiological connections of the olfactory and trigeminal nerves, offering a direct pathway for drugs to reach various brain regions while minimizing systemic exposure. Recent advances in formulation science—including nanoparticles, liposomes, polymeric carriers, in situ gels, and mucoadhesive systems—have significantly enhanced drug retention, permeability, and stability within the nasal cavity. These innovations address major challenges such as mucociliary clearance, limited absorption surface area, enzymatic degradation, and variability in nasal physiology. Nose-to-brain delivery has shown strong potential in the treatment of neurological disorders such as Alzheimer’s disease, Parkinson’s disease, epilepsy, brain tumors, and acute CNS conditions, providing improved onset of action and enhanced therapeutic efficacy. Despite its advantages, translation to clinical practice remains limited due to formulation constraints, safety concerns, dose reproducibility, and a lack of standardized regulatory pathways. This review summarizes current mechanisms, formulation strategies, therapeutic applications, and future prospects of nose-to-brain drug delivery systems, highlighting their growing relevance in modern neurotherapeutics.