**5. Mechanism of SNEF**

In nanoemulsions, entropy change favors dispersion as compared to the energy required to increase the surface area of dispersion. SNEF mainly involves surface free energy which is used by nanoemulsion to produce new surface area in oil and water system can be represented in following equation

$$
\Delta G = \sum N \pi r^2 \sigma \tag{1}
$$

Where ∆G is the surface free energy associated, N is the number of droplets of radius r and ó represents the interfacial energy [17]. Emulsifying agent stabilizes the emulsion when two phases immiscible concerning time to decrease interfacial area. In nanoemulsions, coalescence is avoided due to droplets of monolayer which reduce interfacial energy required for the formulation of nanoemulsion. Free energy required for formulations is low, positive or negative [18].
