**3. Composition of SNEF**

#### **3.1 Lipid/oil phase**

Choice of specific lipid phase has critical importance in the formulation of optimized SNEF. Maximum capacity of lipid to solubilize selected drug and high drug loading


**Table 1.** *Commonly used oils in SNEF.*


#### **Table 2.**

*Commonly used surfactants in SNEF [14].*

capacity are the major criteria for selections of lipid for the development of nanoemulsion. Oil phase has a great ability to increase drug loading capacity for transport of drug in systemic circulation by an increase in absorption of PWSDs [12]. Omega oil is essential fatty acids that the human body needs for metabolic functioning. Human body needs Essential Fatty acids (EFAs) to remove toxic harmful waste products, cell membrane repair and to get optimum nutrition. Main objective of EFAs to generate prostaglandins which controls functions such as blood pressure, heart rate, regulating inflammation, blood clotting etc. Omega oil also helps in treatment of breast, colon and prostate cancer [13]. Some are mentioned in **Table 1**.

#### **3.2 Surfactants**

For design and development of optimized SNEF large no. of compounds have properties of surfactants but few orally acceptable such as nonionic surfactants having low HLB. A large number of surfactant is associated with toxicity. Hence the safety is a major concern while a selection of Surfactant molecule (**Table 2**) [12].
