Due to a continuous increase in consumer demand for better product efficacy, the boundary between the cosmetics field and topical pharmaceuticals is becoming harder to distinguish. To obtain a cosmetic effect, certain penetration of the active compound into the skin is required, although the active compound should not be systemically absorbed after its topical application [5]. The penetration of the active compound through the skin is influenced by several factors, such as the molecular size, the degree of ionization, lipophilicity [3], the synergy between the base component of the formula and the active compound and the synergy between the formulation and the skin [6]. Considering the composition of the skin structure and its barrier property, it seems that a lipid-based formulation will be one of the most appropriate ones for topical application of active compounds [7]. Hence, the emulsion system specifically in the nanoscale range and its process approach in regard to these selection variables will be discussed in detail in this review.