Nanoemulsion-based nasal drug delivery system of olive oil for attenuation of alzheimer's disease (AD) symptoms: preparation, characterization and stability evaluation

The prevalence of Alzheimer's disease (AD) is increasing and one of the factors that can lead to AD is oxidative stress. Olive oil, a strong antioxidant is expected to reverse the action of oxidative stress. Hence, NE-based nasal delivery system is believed to improve olive oil targeted to the brain. In this study, olive oil nanoemulsion was formulated by using phase inversion temperature. Characteristics of prepared nanoemulsions namely; droplet sizes, particles size distribution, zeta potential and pH value were investigated. Stability of the nanoemulsions were also assessed. Results revealed that the droplets size of both 2% and 3% nanoemulsion achieved nano droplet range of< 0.2 µm and uniformly distributed. The value of zeta potentials showed that both nanoemulsion were highly stable and the pH values were within the nasal pH range (4.5-6.5). Based on stability analysis, the nanoemulsion were unstable. In conclusion, NEs with optimal characteristics were successfully prepared, however the stability test results showed that both nanoemulsions were unstable.