Formulation strategies for nose-to-brain delivery of therapeutic molecules

New Opportunity to Formulate Intranasal Vaccines and Drug Delivery Systems Based on Chitosan

“…The gels have an emollient effect, reducing the irritation of the nasal mucosa. Due to the increased viscosity, the fraction of the swallowed substance decreases and a larger amount is thus available at the nasal level for cellular uptake [ 117 ].…”

“…Toxicity tests performed on thermo-sensitive hydrogel based on Pluronic and loaded with chitosan microspheres with lorazepam did not indicate toxicity or irritation to the nasal mucosa [ 117 ].…”

“…Microspheres can form a system of continuous drug release; they also protect drugs against enzyme degradation [ 117 ]. They can be obtained by spray drying, double emulsification, or complexation with other substances [ 131 ].…”

“…Chitosan microemulsion with rivastigmine for intranasal administration has a high potential for distribution in the brain due to mucoadhesive properties, an increased viscosity, and a high contact angle [ 117 ].…”

“…Nano-lipid carriers (NLC) are lipid-based drug delivery systems with an increased stability compared to solid lipid nanoparticles [ 135 ]. Lipid carrier nanostructures have a high capacity to incorporate drugs, have a low water content, and have the ability to incorporate molecules very well during storage, avoiding the premature release of drugs [ 117 , 136 ]. Chitosan-coated nanostructured lipid carriers improve drug absorption and their contact time with the mucosa [ 135 ].…”