18Nasal delivery has become a growing area of interest for drug administration as a consequence of several 19 practical advantages, such as ease of administration and non-invasiveness. Moreover, the avoidance of hepatic 20 first-pass metabolism and rapid and efficient absorption across the permeable nasal mucosa offer a promising 21 alternative to other traditional administration routes, such as oral or parenteral delivery. In fact, nasal delivery 22 has been proposed for a number of applications, including local, systemic, direct nose-to-brain and mucosal 23 vaccine delivery. Nanoemulsions, due to their stability, small droplet size and optimal solubilization properties,