Effect of Mixed Emulsifier on the Physicochemical Properties of Avocado Oil Nano-emulsions

The objective of this study was to provide insights into the synthesis and characterization of oil-in-water nano-emulsions system prepared using mixed surfactant to induce nano-colloid formation. Nano-emulsions (NE) were obtained by pre-homogenization continued with ultrasonication of herbal drug loaded avocado oil, hydrogenated lecithin (HL), and d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) in the aqueous phase. The NE constituted with vary of surfactant ratio, surfactant to oil ratio, and oil content to investigate the physicochemical properties and storage stability. Thus, the morphology NE was examined and performed in regularly spherical shape distributed within 33–270 nm. Where the forming of micelle was increasing the polydispersity index and confirmed by TEM analysis. The results indicated that particle size of the nano-emulsions was majorly affected by the surfactant ratio and surfactant concentration. Moreover, the presence of TPGS decrease the phase transition region until completely eliminate it and make the NE become thermally stable. To investigate the stability of NE, visual observation was done and found that the unstable NE run into phase separation less than 24 hours. In contrast, the stable NE was found to be stable more than 365 days where found affected by the presence of micelle. The current result suggests that mixing TPGS and HL enhance the NE stability and induce micelle formation significantly. On the other hand, TPGS perform significant improvement in stability of NE and establish it be promising lipophilic compound carrier.