Preparation and characterization of clove essential oil-loaded liposomes

•Ethanol injection method was applied to encapsulate clove essential oil into liposomes.•Liposomes were made either from Phospholipon 80H, Phospholipon 90H or Lipoid S100.•The liposome formulations proved stability after 2months of storage at 4°C.•The formulations protect eugenol from degradation induced by UV light exposure.•Eugenol loaded liposomes maintain the DPPH scavenging activity of free Eug. In this study, suitable formulations of natural soybean phospholipid vesicles were developed to improve the stability of clove essential oil and its main component, eugenol. Using an ethanol injection method, saturated (Phospholipon 80H, Phospholipon 90H) and unsaturated soybean (Lipoid S100) phospholipids, in combination with cholesterol, were used to prepare liposomes at various eugenol and clove essential oil concentrations. Liposomal batches were characterized and compared for their size, polydispersity index, Zeta potential, loading rate, encapsulation efficiency and morphology. The liposomes were tested for their stability after storing them for 2months at 4°C by monitoring changes in their mean size, polydispersity index and encapsulation efficiency (EE) values. It was found that liposomes exhibited nanometric oligolamellar and spherical shaped vesicles and protected eugenol from degradation induced by UV exposure; they also maintained the DPPH-scavenging activity of free eugenol. Liposomes constitute a suitable system for encapsulation of volatile unstable essential oil constituents.