Department of Pharmaceutical Technology and Biopharmaceutics, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090 Vienna, Austria.
Pharmaceutics. 2011 May 30;3(2):275-306. doi: 10.3390/pharmaceutics3020275.
Mild non-ionic sucrose ester surfactants can be employed to produce lipid-based drug delivery systems for dermal application. Moreover, sucrose esters of intermediate lipophilicity such as sucrose stearate S-970 possess a peculiar rheological behavior which can be employed to create highly viscous semi-solid formulations without any further additives. Interestingly, it was possible to develop both viscous macroemulsions and fluid nanoemulsions with the same chemical composition merely by slight alteration of the production process. Optical light microscopy and cryo transmission electron microscopy (TEM) revealed that the sucrose ester led to the formation of an astonishing hydrophilic network at a concentration of only 5% w/w in the macroemulsion system. A small number of more finely structured aggregates composed of surplus surfactant were likewise detected in the nanoemulsions. These discoveries offer interesting possibilities to adapt the low viscosity of fluid O/W nanoemulsions for a more convenient application. Moreover, a simple and rapid production method for skin-friendly creamy O/W emulsions with excellent visual long-term stability is presented. It could be shown by franz-cell diffusion studies and in vitro tape stripping that the microviscosity within the semi-solid formulations was apparently not influenced by their increased macroviscosity: the release of three model drugs was not impaired by the complex network-like internal structure of the macroemulsions. These results indicate that the developed semi-solid emulsions with advantageous application properties are highly suitable for the unhindered delivery of lipophilic drugs despite their comparatively large particle size and high viscosity.
温和的非离子型蔗糖酯表面活性剂可用于制备用于经皮应用的脂质药物传递系统。此外，具有中等亲脂性的蔗糖酯，如硬脂酸蔗糖酯 S-970，具有独特的流变行为，可用于创建高粘性半固体制剂，而无需任何其他添加剂。有趣的是，仅通过轻微改变生产工艺，就可以用相同的化学成分开发粘性大乳剂和流体纳米乳剂。光学显微镜和冷冻传输电子显微镜（TEM）表明，在大乳剂系统中，仅以 5%w/w 的浓度，蔗糖酯就导致形成了惊人的亲水网络。在纳米乳液中还检测到少量由剩余表面活性剂组成的结构更精细的聚集物。这些发现为适应流体 O/W 纳米乳剂的低粘度以实现更方便的应用提供了有趣的可能性。此外，还提出了一种简单快速的生产方法，用于制备具有优异视觉长期稳定性的亲肤奶油状 O/W 乳液。Franz 细胞扩散研究和体外胶带剥离表明，半固体制剂中的微粘度显然不受其宏观粘度增加的影响：三种模型药物的释放并未受到大乳剂中复杂的网络状内部结构的影响。这些结果表明，尽管开发的半固体乳剂具有有利的应用性质，但由于其相对较大的粒径和高粘度，仍非常适合亲脂性药物的无阻传递。
