High internal phase emulsions solely stabilized by natural oil-based nonionic surfactants as tea tree oil transporter

Abstract

The stable high internal phase emulsions (HIPEs) were solely stabilized by Palm kernel oil ethoxylates (SOE-N-60) and used as the delivery system of tea tree oil (TTO). The effects of internal phase volume fraction, SOE-N-60 concentration and emulsification time on the stability of HIPEs were studied systematically by Mastersizer 2000 instrument, Lx POL polarizing microscope and rheometer, etc. The experimental results demonstrated that stable HIPEs with internal phase fraction of 84 vol% can be only prepared with 5 wt% surfactant concentrations. Microscopy images showed that the deformation of emulsion droplet and the particle size distribution of the HIPEs were polydispersity. Rheological tests also proved that the emulsion exhibited elastic-gel properties and deformation recovery degree could reach 90 %. The antibacterial experiment indicated that HIPEs prepared by natural oil-based surfactant can effectively protect the encapsulated tea tree oil (TTO), which not only increased the bioavailability of tea tree oil, but also effectively solved the disadvantages of TTO such as volatile and hydrophobic. In addition, the HIPEs stabilized by SOE-N-60 had excellent stability, which will broaden its potential applications in medicine, food and personal care.