Inter-Departmental Program for Biotechnology, Technion - Israel Institute of Technology, Haifa 32000, Israel; The Russell Berrie Nanotechnology Institute, Technion - Israel Institute of Technology, Haifa 32000, Israel.
Int J Pharm. 2013 Dec 15;458(1):208-17. doi: 10.1016/j.ijpharm.2013.09.024. Epub 2013 Oct 3.
Self-microemulsifying drug delivery systems (SMEDDS) increase the solubility of lipophilic drugs. One barrier to their wide application is their liquid nature. We report on a new method to solidify SMEDDS-their incorporation in sponges made from a hydrophilic natural polymer. Using different freeze-drying schemes, sponges were prepared from alginate gels containing microemulsions. The sponges' structures were studied with scanning electron microscopy and small angle X-ray scattering. The oil droplets survived the drying process, and SMEDDS were present as 9 nm-sized objects in the dried sponges. The sponges were rehydrated in water, and evidence of the presence of SMEDDS in the rehydrated sponges was found. A model hydrophobic molecule, Nile red, was soluble in all dry and rehydrated sponges. SMEDDS containing Nile red were gradually released from the sponges, at a rate that depended on the drying method. The equilibrium water uptake of the sponges was also found to be influenced by the drying scheme. The combination of SMEDDS and sponges may be a way to overcome the disadvantages of each component separately, provide a solid dosage form for SMEDDS that can sustain the release of drugs and also enable utilization of hydrophilic sponges for the delivery of hydrophobic drugs.
自微乳药物传递系统 (SMEDDS) 能够增加脂溶性药物的溶解度。其广泛应用的一个障碍是其液体性质。我们报告了一种将 SMEDDS 固化的新方法——将其掺入由亲水性天然聚合物制成的海绵中。使用不同的冷冻干燥方案，从含有微乳液的藻酸盐凝胶中制备了海绵。使用扫描电子显微镜和小角 X 射线散射研究了海绵的结构。油滴在干燥过程中得以幸存，并且 SMEDDS 以 9nm 大小的物体形式存在于干燥的海绵中。海绵在水中重新水合，在再水合的海绵中发现了存在 SMEDDS 的证据。一种模型疏水分子，尼罗红，可溶于所有干燥和再水合的海绵中。含有尼罗红的 SMEDDS 从海绵中逐渐释放，释放速度取决于干燥方法。还发现海绵的平衡吸水率也受到干燥方案的影响。SMEDDS 和海绵的结合可能是克服两者各自缺点的一种方法，为 SMEDDS 提供一种可以持续释放药物的固体剂型，同时也能够利用亲水性海绵来输送疏水性药物。
