Abstract: The preparation of oil-in-water type polyprenols nanoemulsion from Ginkgo biloba L.leaves polyprenols with inversed phase emulsification (EIP) method was studied.On the basis of single factor,the effects of factors,such as hydrophile-lipophile balance (HLB) number,proportion of emulsifier to polyprenol,mixing time,emulsionizing temperature,and mixing rate,on the preparation process and average diameter of polyprenols nanoemulsion were investigated.The preparation conditions,i.e.,mixing time,emulsionizing temperature,and mixing rate,were also optimized by using response surface method (RSM).Results showed that the optimum conditions were mixing time 12 min,emulsionizing temperature 60 ℃,and mixing rate 17 000 r/min.Under these conditions,the average diameter of polyprenols nanoemulsion was the minimum and the RSD of the actual value (97 nm) with the fitted value (92 nm) was 2.7% (<5%),and the distribution coefficient of particle diameters was 0.383.The optimal parameters obtained by simulating this model were reliable in predicting the actual operation,and had certain guiding significance.The centrifugal stability,storage stability,diepersity,and freezing-thawing dispersity of polyprenol nanoemulsion under the optimum conditions showed good uniformity and reached 1-level.The freezing-thawing centrifugation stability of polyprenol nanoemulsion showed preliminary visible uniformity,which was 2-level,and kept 2-level.

Key words: Ginkgo biloba L., polyprenols, nanoemulsion, response surface method