Polymeric Nanocarrier-Based Drug Formulations for Enhancing Nose-to-Brain Delivery

Neurological-related diseases are among the most debilitating and difficult to manage. Many possible pharmacological treatments for neurological diseases struggle to cross the blood–brain barrier (BBB) to achieve concentrations that can produce a therapeutic benefit. This is primarily because of the existence of the BBB, which poses significant hurdles for both therapeutic and diagnostic efforts by restricting the entry of most medications. Nasal-to-brain drug transportation has surfaced as an encouraging approach to tackle the difficulties linked with conventional drug administration techniques for neurological disorders. In response, innovative methods for improving drug delivery focus on breaking down the BBB via physical techniques, including optical and photothermal therapy, electrical stimulation, and acoustic or mechanical stimulation. Nanocarriers represent a promising approach for facilitating nasal systemic and brain delivery of active compounds. Hence, the achievement of therapeutically relevant concentrations of exogenous molecules within the body is significantly contingent upon the nanocarriers’ capability to surpass biological barriers. Polymers in nanocarrier formulations can result in significantly enhanced nose-to-brain drug delivery by protecting drugs from premature biodegradation, increasing permeability, improving mucoadhesion, and targeting specific cells in the brain. Polymeric nanocarriers are frequently functionalized with cell-penetrating peptides to further improve the specificity of the loaded therapeutic molecules. This review focuses on the use of nanocarrier-based therapeutic agents to enhance the efficacy of nose-to-brain delivery systems.