An overview of Intranasal Thermoreversible In-situ Gel for brain-targeted drug delivery

Intranasal delivery of drugs is a promising alternative for bypassing the blood-brain barrier, avoiding systemic side effects of pharmaceuticals, and reducing doses to be provided. The drug reaches the central nervous system through olfactory and trigeminal nerve pathways. Recent developments have been made in designing intranasal drug delivery systems for central nervous system therapies to the brain, with a particular focus on thermoreversible hydrogels. These hydrogels possess sol-to-gel transition in response to temperature changes. Various natural, synthetic and semi-synthetic polymers can use for the formulation of thermoversible hydrogels. The mucoadhesive polymers can be incorporated into the gel to improve the retention time of gel at the nasal mucosa. Different kinds of nasal drug delivery models, including in vivo, in vitro and ex vivo models can be employed to evaluate drug transporter interactions, drug absorption, permeability, toxicity, and electrophysiology in nasal mucosa.