Foldvari M
College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada.
J Microencapsul. 1996 Sep-Oct;13(5):589-600. doi: 10.3109/02652049609026043.
Liposornes used for topical applications are often incorporated into a vehicle to achieve suitable viscosity and application properties. The effect of incorporation of liposomes into white petrolatum as a possible dermatological base was investigated. A number of formulae were developed to determine the type of petrolatum base that would be compatible with the liposomes. The physical appearance and stability of the vaseline-liposome (VL) preparations were determined by organoleptic analysis and microscopy. The effect of petrolatum base on the drug release from the liposomes was determined in a flow-through diffusion cell system using a model silastic polymer membrane as barrier. A base containing white petrolatum 46.7% (w/w), stearyl alcohol 6.7% (w/w), cholesterol 13.3 (w/w), Tween 80 16.7% (w/w) and Span 16.7% (w/w) was selected for diffusion studies, since the mixture of this base and liposome preparation, at 1:1.9 (w/w) ratios, provided a stable, dermatologically acceptable dosage form, in which the liposomes were uniformly distributed and their structures were preserved. Diffusion studies showed that the drug release rate decreases 2.5x when the liposomes are incorporated into the vaseline base; however, after a temporary decrease they seem to extend the duration of release beyond that of the original liposomal formula. These studies revealed a possibility of using white petrolatum in the topical application of liposomes.
用于局部应用的脂质体通常被加入到一种载体中，以获得合适的粘度和应用性能。研究了将脂质体加入到作为可能的皮肤病学基质的白凡士林中的效果。开发了许多配方来确定与脂质体相容的凡士林基质类型。通过感官分析和显微镜检查来确定凡士林 - 脂质体（VL）制剂的物理外观和稳定性。在流通扩散池系统中，使用模型硅橡胶聚合物膜作为屏障，测定凡士林基质对脂质体药物释放的影响。选择一种含有46.7%（w/w）白凡士林、6.7%（w/w）硬脂醇、13.3%（w/w）胆固醇、16.7%（w/w）吐温80和16.7%（w/w）司盘的基质进行扩散研究，因为该基质与脂质体制剂按1:1.9（w/w）比例混合时，可提供一种稳定的、皮肤病学上可接受的剂型，其中脂质体均匀分布且其结构得以保留。扩散研究表明，当脂质体加入到凡士林基质中时，药物释放速率降低2.5倍；然而，在短暂降低后，它们似乎能延长释放持续时间，超过原始脂质体制剂的释放持续时间。这些研究揭示了在脂质体局部应用中使用白凡士林的可能性。
