Effects of preparation technologies and entrapment materials on encapsulation efficiencies of three constituents' liposomes / 中成药

ABSTRACT

AIM To prepare the liposomes loaded with celastrol,tanshinone Ⅱ A and tanshinone Ⅱ A sodium sulfonate and to evaluate the effects of preparation technologies and entrapment materials on the encapsulation efficiencies.METHODS The liposomes for three constituents were prepared by film dispersion method and reverse phase evaporation method,respectively.50％ Lecithin high potency,80％ egg yolk lecithin,92％ lecithin high potency and complex phospholipid (5 ∶ 1 for ratio of dipalmitoyl phosphatidylcholine to 50％ lecithin high potency) were served as entrapment materials.The encapsulation efficiencies were thus calculated based on the measured ean sizes and polydispersity of the liposomes.RESULTS Celastrol and tanshinone Ⅱ A sodium sulfonate liposomes accomplished by reverse phase evaporation method got the highest encapsulation efficiency when entrapped with 80％ egg yolk lecithin and 92％ lecithin high potency,respectively,which were higher than those prepared by film dispersion method.And celastrol liposomes exhibited an even superior performance than tanshinone Ⅱ A sodium sulfonate liposomes.Tanshinone Ⅱ A lipisome prepared by film dispersion method and then entrapped with 50％ lecithin high potency obtained its the highest value of encapsulation efficiency,which was much lower than those of another two liposomes.CONCLUSION Reverse phase evaporation method is appropriate for hydrophobic celastrol with multiple hydrogen bonds and hydrophilic sodium tanshinone Ⅱ A without hydrogen bonds to prepare their liposomes,while film dispersion method is applicable to hydrophobic tanshinone Ⅱ A without hydrogen bonds.