Nasal mucosa offers advantages to deliver drugs to brain via olfactory route thus provides rapid onset of drug
action and hence faster therapeutic effect. Therefore, various strategies have been proposed to improve the delivery of different
drugs to brain including liposomes, colloidal drug carriers, micelles, chimeric peptide technology and nanotechnology
through nasal route. The low blood level of folates is the primary cause of depression in Alzheimer’s disease. Folic
acid is a water soluble vitamin showing difficulty in crossing the blood brain barrier and thus was formulated as niosomal
nasal drug delivery systems to target the brain. In the present work, folic acid niosomes were prepared using different nonionic
surfactants i.e., span 20, span 60, span 80, tween 20, tween 80 and cholesterol by using lipid layer hydration technique.
These were evaluated for particle size, viscosity, osmotic shock, entrapment efficiency and in vitro drug release.
The influence of different formulation variables such as surfactant type, surfactant concentration, and cholesterol concentration
was optimized for required size distribution, viscosity, entrapment efficiency and in vitro release. The prepared
niosomes were in the size range of 3.05–5.625µm. Niosomes prepared with span 60 and cholesterol in the ratio of
1:1(50mg: 50mg) shown higher entrapment efficiency of 69.42% and better in vitro drug release of 64.2% at the end of 12
hrs and therefore considered as optimized formulation. The stability studies were carried out by storing niosomes at 4±1°C
and 25±1°C and showed good stability over the period of storage. The release of drug from niosomes followed anomalous
diffusion and obeyed first order release kinetics. Ex-vivo perfusion studies were also performed by using rat model, about
48.15% of drug was found to be absorbed through nasal cavity at the end of 6 hrs.