Construction of Pickering emulsion based on modified artificial bezoar/Acorus tatarinowii essential oil: Ozone stability evaluation and in vitro release and in vivo evaluation

Essential oils, key active components in traditional Chinese medicine (TCM) with broad pharmacological activities, are prone to oxidation and degradation during storage and use, limiting their clinical application. This study, guided by the concept of "combination of medicine and adjuvant", uses PEG 20,000 modified artificial bezoar (MAB) as a Pickering emulsion stabilizer to encapsulate Acorus tatarinowii essential oil (ATEO). The MAB shows increased contact angle and remarkable changes in surface morphology and chemical structure. Single-factor experiments optimize the emulsion preparation conditions: MAB concentration at 15 mg/mL, oil phase volume fraction at 60 %, shear rate at 12,000 rpm, and shear time at 2 min. The resulting Pickering emulsion is of O/W type, with a particle size of 1300 nm and a zeta potential of 32.50 mV, exhibiting good stability. Ozone stability tests reveal that the Pickering emulsion effectively reduces the peroxide value (POV) and malondialdehyde value (MDA) of ATEO, curbing the oxidative degradation of its major components. In vitro and in vivo release behavior studies show that the Pickering emulsion encapsulated ATEO exhibits different regulatory effects on α- and β-asarone. Overall, this study offers a novel and effective strategy for enhancing the oxidative stability of essential oils in TCM. • Pickering emulsion enhances Lingzhu Pulvis oil stability via "combination of medicine and adjuvant". • Modified artificial bezoar (MAB) stabilizes O/W Pickering emulsions via optimized preparation conditions. • MAB-stabilized Pickering emulsion vs. oil/physical mixtures: component/property changes under ozone. • In vitro / in vivo release differences between oil and MAB emulsion.