Abstract: This study was undertaken to prepare medium-chain fatty acid (MCFA)-VC complex liposome using lecithin and cholesterol as membrane materials and optimize the preparation process. Four preparation methods including thin film method, high pressure-thin film method, double emulsification method and high pressure-double emulsification method were compared in terms of entrapment efficiency and liposomal particle size. As a result, high pressure-double emulsification method was found to be the best method. One-facto-at-a-time experiments were carried out to determine the optimal preparation conditions as follows: total lipid material cocentration of 5.0 g/100 mL, MCFAs concentration of 10.0 mg/mL, VC concentration of 3.0 mg/mL, lecithin/absolute ethanol ratio of 1:10 (g/mL), mass ratio of lecithin to cholesterol of 4:1, mass ratio of Tween to total lipid material of 3:10, mass ratio of VE to lecithin of 5:1, and twice repeated ultramicroemulsification at 120 MPa, respectively. <br /> Under these optimal conditions, the entrapment efficiencies of MCFA and VC were 49.01% and 54.19%, respectively and a mean particle size of 90.3 nm was achieved. The three indexes had little change during storage at 4 ℃ for 15 days, thus indicating excellent stability at low storage temperature.

Key words: medium-chain fatty acids；VC； liposome；dynamic high pressure microfluidization (DHPM)；entrapment efficiency, stability