Effect of sodium alginate and different types of oil on the physical properties of ultrasound-assisted nanoemulsions

The aim was to develop stable nanoemulsions as potential delivery systems for bioactive ingredients, pharmaceutical products, and nanoparticles dispersed in organic solvents. The effect of sodium alginate (SA) concentration (0.5, 1.0 and 1.5% w/w) and the type of oil (corn oil (CO), oleic acid (OA), olive oil, and unrefined and refined coconut oil), in combination with tween 80, on the quality of nanoemulsions produced by ultrasound was evaluated. CO and OA nanoemulsions with 0.5% SA showed the lowest droplet size, polydispersity index, and zeta potential. After ultrasonication, CO and OA nanoemulsions exhibited a reduction in droplet size, polydispersity index, and viscosity. Coarse emulsions showed near-Newtonian behavior while the nanoemulsions exhibited Newtonian behavior. Fourier-transform infrared spectroscopy did not reveal differences among SA solutions with OA and CO nanoemulsions. CO and OA nanoemulsions possessed a spherical and asymmetric branched structure, respectively. Stability studies revealed that nanoemulsions may be stable upon storage for 28 days at room temperature.