2.2.4 Preparation of nanoemulsion
The nanoemulsions were prepared using spontaneous nanoemulsification method [17] the oil phase was heated gently at 24-50 c for 5 min surfactant and co-surfactant (smix) were mixed together and heat at same temperature .oil and smix were mixed to from homogenous isotropic mixtures and were slowly titrated with aqueous phase to obtain clear and transparent nanoemulsions. the order of addition of excipients is very important for nanoemuisions formulation.Nanoemulsion are formed only if surfactant is mixed with oil phase followed by addition of water ,Addition of surfactants to aqueous phase followed by addition oil phase leads to formation of macroscopic emulsions, This is a key differentiation test from micro emulsion. which are not influenced by order of addition of excipients[18]. Drug loaded nanoemulsions were prepared in similar manner by adding the Drug (12mg) to oil phase curcumin solution was prepared in 20 (V/V) tween 80 solution in distilled water