本研究擬以氫化磷脂質(hydrogenated lecithin, HL)混合硬脂酸(stearic acid, SA)製備微脂粒包覆維生素E醋酸酯(dl-α-tocopheryl acetate, VEA)或天然維生素E(α-tocopherol, VE)，期望能開發出可長期儲存安定之配方。並透過粒徑(particle size)、粒徑分佈係數(polydispersity index)、界面電位(zeta potential)及螢光偏極化(fluorescence polarization)的量測，來探討微脂粒之理化現象。進一步使用穿透式電子顯微鏡(transmission electron microscope, TEM)直接觀察微脂粒結構，可證實微脂粒之形成與構造。同時篩選出較安定之微脂粒配方，分別進行兩種不同維生素E之包覆效率(entrapment efficiency，EE%)實驗。結果發現以組成配方HL/SA:VEA及HL/SA:VE(9/1:1(莫耳比))，為儲存穩定天數(Stable days)最長的配方(<63 days)，而HL/SA:VEA及HL/SA:VE(5/5:1(莫耳比))，則是包覆效率最高的配方(＞80 %)。除此之外，透過體外皮膚穿透實驗，分別比較兩種微脂粒包覆VEA或VE與兩種不同維生素E分散液之皮膚穿透效率。由實驗結果得知，分散在水溶液中之不同維生素E均無法穿透皮膚，但以混合HL/SA微脂粒包覆VE或VEA則具有皮膚滲透之效果。 This research aimed to mix hydrogenated lecithin (HL) with stearic acid (SA) to encapsulate dl-?tocopheryl acetate (VEA) or ?tocopherol (VE) for development of a stable formula. The average particle size, polydispersity index, zeta potential and fluorescence polarization were measured to study phenomenon of liposome. Transmission electron microscope, TEM has been used for observation of liposomes structure directly. Furthermore a reliable liposomal formulation was selected to carry out experiment of entrapment efficiency for VEA and VE.
The result showed that formulas of HL/SA:VEA and HL/SA:VE(9/1:1, molar ratio) can be stored up to 63 stable days and formulas of HL/SA:VEA and HL/SA:VE(5/5:1, molar ratio) expressed the highest entrapment efficiency. In addition, VEA or VE dispersion and the liposomes entrapped vitamin E were utilized to evaluate the permeation efficiency by skin penetration of drug in vitro. As the result shown, VEA or VE dispersion cannot penetrate into skin, but liposomes entrapped VE or VEA can.
