Schmidts T, Dobler D, Nissing C, Runkel F
Institute of Biopharmaceutical Technology, University of Applied Sciences Giessen-Friedberg, Wiesenstr. 14, 35390 Giessen, Germany.
J Colloid Interface Sci. 2009 Oct 1;338(1):184-92. doi: 10.1016/j.jcis.2009.06.033. Epub 2009 Jun 18.
Multiple W/O/W emulsions for topical application using Span 80 as a lipophilic emulsifier were prepared. Several hydrophilic emulsifiers were tested in respect of their suitability for the preparation of multiple emulsions. In addition, the effect of different oil-phase compositions on emulsion stability was investigated. The physicochemical parameters of the formulations were characterized and their long-term stability was evaluated by means of rheological measurements, droplet size observations and conductivity analysis. As discovered, the modification of an oil-phase composition results in a decrease in the diffusion coefficient of water and water-soluble substances and, consequently, in enhanced stability. The influence of the release of electrolytes from the inner to the outer water phase on the emulsion stability behaviour was investigated. It was found, that the effect of the hydrophilic emulsifiers on the formulation properties is related not only to its HLB value, but rather to its chemical composition. As a result, polyethoxylated ethers of fatty alcohols (C=16-18) with HLBs between 15.3 and 16.2 appear to be the most suitable ones for creating stable formulations.
制备了以Span 80作为亲脂性乳化剂的用于局部应用的多重水包油包水型乳液。测试了几种亲水性乳化剂制备多重乳液的适用性。此外，研究了不同油相组成对乳液稳定性的影响。对制剂的理化参数进行了表征，并通过流变学测量、液滴尺寸观察和电导率分析评估了它们的长期稳定性。结果发现，油相组成的改变会导致水和水溶性物质的扩散系数降低，从而提高稳定性。研究了电解质从内水相释放到外水相对乳液稳定性行为的影响。发现亲水性乳化剂对制剂性质的影响不仅与其HLB值有关，更与其化学组成有关。因此，HLB值在15.3至16.2之间的脂肪醇（C = 16 - 18）的聚乙氧基化醚似乎是制备稳定制剂最合适的乳化剂。
