Preparation of Tamanu Oil Nanoemulsions by Phase Inversion Temperature

Abstract

In this study, the phase inversion temperature (PIT) method was used to prepare a stable tamanu oil nanoemulsion at the lowest surfactant content. The factors affecting the formation of nanoemulsions such as type of surfactant, surfactant to oil ratio (SOR), and water content were investigated. The results showed that Tween 80 is suitable for making a stable nanoemulsion. The SOR is more than or equal to 1.5:1 produced emulsions with particle size less than 100 nm. The particle size decreased as SOR, and water content increased. A higher quantity of surfactant caused higher turbulence and affinity towards the aqueous phase, resulting in smaller droplets. Decreasing droplet size by increasing water content may result from a decreased viscosity of the surfactant at the interface that promotes fluidity and the easy movement of the oil phase towards the aqueous phase. The SOR of 3:1 and water content of 80% were selected due to cost, taste, and toxicity concerns. The impact of storage condition on nanoemulsion stability was also investigated. After one month, samples were stored in the refrigerator had an insignificant increase in absorbance. Particle size analysis also showed a similar result (< 20 nm).