测定25℃条件下油烯基聚氧乙烯(20)醚在乙酸丁酯/水介质中的相图,探讨生物表面活性剂脱氧胆酸钠(NaDC)对体系相行为和流变性质的影响。进一步对上述体系所形成的溶致液晶进行对姜黄素的保护和体外释放研究。结果表明:体系中存在六角相和立方相,加入NaDC后六角相缩小,立方相消失。这些溶致液晶相在稳态剪切条件下均表现为剪切稀释的性质;但立方状液晶表现出较突出的弹性性质,表现在tan6〈0.1,而六角状液晶表现典型的黏弹性性质(tanδ为0.47~0.54),而且加入NaDC使六角状液晶的特征松弛时间增大。在光照下溶致液晶对姜黄素有保护作用,加入NaDC可使保护作用增强。这些液晶相对姜黄素有一定的缓释效果,NaDC的加入延长了其释放到达平衡所需要的时问,增强缓释效果。
The phase diagram of oleyl polyoxyethylene (20) ether/butyl acetate/water was determined at 25 ℃, and the influence of the biosurfactant sodium deoxycholate (NaDC) on the phase behavior and theological properties of the system was investigated. Furthermore, the protection and in vitro release behavior of curcumin in the liquid crystals were studied. Hexagonal and cubic crystals were found in the ternary system. When adding NaDC, the area of hexagonal phase became smaller and the cubic phase disappeared. All investigated samples followed a shear-thinning behavior under steady shear. The cubic crystals showed high elasticity with tan 0 values less than 0.1, while the hexagonal crystals demonstrated typical visco-elasticity with tan 0 values between 0.47 and 0.54. The characteristic relaxation time of the hexagonal crystals increased after adding NaDC. Curcumin could be protected by the liquid crystals against sun light. Surcumin solved in the liquid crystals exhibited slow release behavior. Moreover, the protection effect was enhanced and the equilibrium time of release was extended in NaDC containing systems.