Modified Amber Particles as a Stabilizer to Construct Oil-in-Water Pickering Emulsions for Improved Thermal Stability of Essential Oil.

Lingzhu Pulvis is a classic formulation for treating febrile convulsions in children. However, essential oil (AT-EO) in this prescription is prone to volatilization and oxidation, compromising the efficacy and quality control of this formulation. Herein, based on the concept of "combination of medicine and adjuvant", Pickering emulsion technology was applied to enhance the stability of AT-EO using modified amber as a stabilizer. Amber was a resinous medicinal powder in Lingzhu Pulvis and was modified into a suitable stabilizer for Pickering emulsion through surface modification. A thermal stability study indicated that Pickering emulsion, stabilized by modified amber, exhibited a higher retention rate of AT-EO and lower levels of peroxide value and malondialdehyde content compared to those of the pure AT-EO group after heat treatment at 40 °C for 1, 3, and 8 h. Additionally, component analysis in content and composition revealed that the volatile components of AT-EO in the Pickering emulsion were more stable during the thermal treatment process. This study convincingly illustrates the potential of a Pickering emulsion stabilized with modified medicinal powders to improve the thermal stability of the essential oil.