α-生育酚脂质体的配方优化及其稳定性分析

To protect the activity of α-tocopherol and improve its stability, α-tocopherol liposomes were prepared by using thin film hydration method with egg yolk lecithin and cholesterol as wall materials and Tween 80 as emulsifier. The effects of the mass ratio of phospholipids to cholesterol, the mass ratio of phospholipids to α-tocopherol, and the volume of absolute ethanol on the quality of liposomes were analyzed by single factor experiments with the entrapment efficiency, particle size, and Zeta potential as indexes. Based on the single factor experiments, response surface methodology was adopted to optimize the formula of α-tocopherol liposome with the entrapment efficiency of α-tocopherol as response value, and the influence of different factors on the stability of α-tocopherol liposomes was investigated. Results show that the optimum parameters for the preparation of α-tocopherol liposome were as follows: phospholipid, 280.00 mg; mass ratio of phospholipids to cholesterol, 6.22:1; mass ratio of phospholipids to α-tocopherol, 18.70:1; absolute ethanol, 14.65 mL. Under these conditions, the entrapment efficiency of α-tocopherol liposomes was 87.39±1.12%, the average particle size was 181.30±3.45 nm (PDI=0.201±0.013), and the Zeta potential value was -38.90±0.32 mV. The spherical structure of α-tocopherol liposomes, which has uniform size and good dispersion, was observed by electron microscope. Stability analysis results suggest that liposomes could be well stabilized at a sucrose concentration of 0.5% or less, but pH, ion concentration, heating temperature and time, as well as storage temperature and time all significantly affected the stability. The study indicates that liposomes can maintain the activity of α-tocopherol and improve its bioavailability to effectively expand the range of applications.