Effect of Oil Type, Aliphatic Alcohol, and Ionic Surfactants on the Formation and Stability of Ceramide-2 Enriched Nanoemulsions

Abstract

Oil-in-water nanoemulsions are finding increasing use as delivery systems to encapsulate lipophilic bioactive components in personal care and pharmaceutical. The aim of this study was to optimize the composition and stability of ceramide-2 nanoemulsions. The nanoemulsions were prepared by high pressure homogenizer emulsification method using sodium dilauramidoglutamide lysine (DLGL) as surfactant. Results showed that the oil type and concentration had an appreciable impact on the particle size and stability of the ceramide-2 enriched nanoemulsions. The presence of the aliphatic alcohol altered the curvature of the surfactant molecular and increased the stability of nanoemulsions. The zeta potential of nanoemulsions decreased with the addition of cetyl trimethyl ammonium chloride (1631), which weakens the electrostatic interactions between droplets and lowers the stability of the nanoemulsions. The particle size decreased with increasing concentrations of both sodium dodecyl sulfate (SDS) and cocoamidopropyl betaine (CAB). The variation of zeta potential with SDS and CAB was insignificant, which was attributed to the high zeta potential value resulted from anionic gemini surfactant DLGL. The instability mechanism of nanoemulsions was the Ostwald ripening. This study demonstrated that the addition of aliphatic alcohol, SDS, or CAB was beneficial to the stability of ceramide-2 nanoemulsions and decreased the Ostwald ripening rate.