Preparation and optimization of Vitamin E acetate liposomes using a modified RESS process combined with response surface methodology

Abstract

Liposomes have attracted much attention in the pharmaceutical and cosmetic industries. In this study, the Vitamin E acetate (VEA) liposomes are prepared using a modified rapid expansion of supercritical solution (RESS) process. The effects of operation conditions (e.g., temperature, pressure, and the mass ratio of ethanol to CO2) on encapsulation efficiency (EE), polydispersity index (PDI), and Zeta-potential of the liposomes are investigated. Additionally, the response surface methodology (RSM) based on Box–Behnken design (BBD) is employed to reveal the interaction between the operation conditions and optimize the VEA liposomes preparation process. The high encapsulation efficiency of 98.63 ± 0.42% is obtained at the temperature of 59.55 °C, the pressure of 23.45 MPa, and the mass ratio of ethanol to CO2 of 0.36%. The particle size distribution and morphology of VEA liposomes indicate that liposomes prepared by this technology can meet the requirements of the Chinese Pharmacopeia Commission (2010). Eventually, the stability and in vitro release behaviors of VEA liposomes are determined. The results show that the prepared liposomes have good stability, and the slow and sustained release is observed during the in vitro release experiment.