Effect of Emulsifiers on Physical Properties and Stability of Oral Rice Bran Oil Nanoemulsions

Abstract:

The objective of this research was to investigate the effects of emulsifier types and concentrations on the physical properties and stability of rice bran oil O/W nanoemulsions for oral administration. The nanoemulsions were formulated by using 10% of rice bran oil (RBO) as an oil phase and either single emulsifier (1,3,5% sodium caseinate (SC) or 4,6,8% polysorbate 80 (P80)) or mixed emulsifiers (1,3,5% SC and 4,6,8% P80). The nanoemulsions were prepared by Microfluidizer^® at 1,500 bar for five cycles and evaluated for droplet size, polydispersity index (PDI), zeta potential, pH, and viscosity. Their physical stability was tested under heating-cooling cycles for six cycles. The results indicated that the nanoemulsions with SC (162.50-163.48 nm) had a larger droplet size than those with P80 (90.11-105.94 nm). The concentration of SC had no significant effect on the droplet size, whereas increasing the P80 concentration resulted in a significant decrease in the droplet size. For the formulations with mixed emulsifiers, an increase in the concentration of the second emulsifier leaded to a decrease in the droplet size. All nanoemulsions had narrow size distribution (PDI < 0.2), negative charge, neutral pH value, and low viscosity. The nanoemulsions with alone SC showed a larger negative charge value as compared to those with alone P80 and mixed emulsifiers. All formulations with a single emulsifier were physically stable under heating-cooling cycles for six cycles, whereas the nanoemulsions with mixed emulsifiers showed good stability for only those with the low SC concentration (1%). The rice bran oil O/W nanoemulsions obtained from this study could be developed as oral delivery systems for further applications in the pharmaceutical and food industries.

• Periodical: Key Engineering Materials (Volume 859)
• Pages: 197-202
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.859.197
• Online since: August 2020
• Authors: Punnarut Nongnuan, Dusadee Charnvanich*
• Keywords: Oral Nanoemulsion, Physical Stability, Polysorbate 80, Rice Bran Oil, Sodium Caseinate

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