Advances in Aerosol Formulation for Targeted Delivery of Therapeutic Agents from Nose to Brain

The intricate anatomical and physiological barriers that prohibit pharmaceuticals from entering the brain continue to provide a noteworthy hurdle to the efficient distribution of medications to brain tissues. These barriers prevent the movement of active therapeutic agents into the brain. The present manuscript aims to describe the various aspects of brain-targeted drug delivery through the nasal route. The primary transport mechanism for drug absorption from the nose to the brain is the paracellular/extracellular mechanism, which allows for rapid drug transfer. The transcellular/intracellular pathway involves the transfer across a lipoidal channel, which regulates the entry or exit of anions, organic cations, and peptides. Spectroscopy and PET (positron emission tomography) are two common methods used for assessing drug distribution. MRI (Magnetic resonance imaging) is another imaging method used to assess the efficacy of aerosol drug delivery from nose to brain. It can identify emphysema, drug-induced harm, mucus discharge, oedema, and vascular remodeling. The olfactory epithelium's position in the nasal cavity makes it difficult for drugs to reach the desired target. Bi-directional aerosol systems and tools like the "OptiNose" can help decrease extranasal particle deposition and increase particle deposition efficiency in the primary nasal pathway. Direct medicine administration from N-T-B, however, can reduce the dose administered and make it easier to attain an effective concentration at the site of activity, and it has the potential to be commercialized.