**4. Concept of nanoemulsions within lipid‐based formulation**

The potentiality of nanoemulsions within lipid‐based drug delivery systems was explored almost four decades ago. In simple term, nanoemulsions are the emulsions comprising nanosized droplets and they are well dispersed, transparent and kinetically stable for several months. Their physical stability can be improved by careful selection of surfactants and the ratio of oil/water/surfactant and also the efficiency of equipment used to reduce droplet sizes. Not only for oral delivery, nanoemulsions are used as greater transmucosal and transdermal drug delivery vehicles due to their remarkable wetting, spreading and penetration abilities.
