Particulate formulations based on chitosan for nose-to-brain delivery of drugs. A review

The treatment of central nervous system diseases is very difficult due to the inability of drugs to permeate into the brain from the bloodstream. The intranasal route of administration allows for rapid drug delivery directly from the nasal mucosa to the brain, minimizing systemic exposure. Chitosan is one of the most used excipient for nasal formulations due to its mucoadhesive and penetration enhancement properties. Several chitosan formulations have been proposed for the nose-to-brain delivery of drugs (solutions, suspension, gels, microemulsion, and powers). Particulate formulations can offer advantages over liquid medication, such as greater stability, greater convenience, and long residence time of the drug in the nasal cavity. This review provides a summary and discussion of recent data on nasal particulate formulations based on chitosan, its salts, and derivatives for nose-to-brain delivery of drugs. We also summarize the drugs studied for this administration route and the preparation methods of these formulations.