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.