Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), 381 Royal Parade, Parkville, VIC 3052, Australia; CSIRO Materials Science and Engineering, Bag 10, Clayton South MDC, VIC 3169, Australia.
CSIRO Materials Science and Engineering, Bag 10, Clayton South MDC, VIC 3169, Australia.
J Colloid Interface Sci. 2013 Feb 15;392:288-296. doi: 10.1016/j.jcis.2012.09.051. Epub 2012 Oct 8.
Liquid crystalline nanostructured particles, such as cubosomes and hexosomes, are most often colloidally stabilised using the tri-block co-polymer Pluronic® F127. Although the effect of F127 on the internal particle nanostructure has been well studied, the associative aspects of F127 with cubosomes and hexosomes are poorly understood. In this study the quantitative association of F127 with phytantriol-based cubosomes and hexosomes was investigated. The amount of free F127 in the dispersions was determined using pressure ultra-filtration. The percentage of F127 associated with the particles plateaued with increasing F127 concentration above the critical aggregation concentration. Hence the free concentration of F127 in the dispersion medium was proposed as a key factor governing association below the CMC, and partitioning of F127 between micelles and particles occurred above the CMC. The association of F127 with the particles was irreversible on dilution. The F127 associated with both the external and internal surfaces of the phytantriol cubosomes. The effects of lipid and F127 concentration, lipid type, dilution of the dispersions and internal nanostructure were also elucidated. A greater amount of F127 was associated with cubosomes comprised of glyceryl monooleate (GMO) than those prepared using phytantriol. Hexosomes prepared using a mixture of phytantriol and vitamin E acetate (vitEA) had a greater amount of F127 associated with them than phytantriol cubosomes. Hexosomes prepared using selachyl alcohol had less F127 associated with them than phytantriol:vitEA-based hexosomes and GMO-based cubosomes. This indicated that both the lipid from which the particles are composed and the particle internal nanostructure have an influence on the association of F127 with lyotropic liquid crystalline nanostructured particles.
液晶纳米结构粒子，如立方纳米囊和六方纳米囊，通常使用三嵌段共聚物 Pluronic® F127 进行胶体稳定。尽管 F127 对粒子内部纳米结构的影响已经得到了很好的研究，但 F127 与立方纳米囊和六方纳米囊的缔合方面的理解还很有限。在这项研究中，定量研究了 F127 与植物醇基立方纳米囊和六方纳米囊的缔合。通过压力超滤测定分散体中游离 F127 的量。随着临界聚集浓度以上的 F127 浓度的增加，F127 与粒子的缔合百分比达到平台。因此，在 CMC 以下，分散介质中游离 F127 的浓度被认为是控制缔合的关键因素，而 F127 在胶束和粒子之间的分配则发生在 CMC 以上。稀释时，F127 与粒子的缔合是不可逆的。F127 与植物醇立方纳米囊的内外表面都发生了缔合。还阐明了脂质和 F127 浓度、脂质类型、分散体的稀释和内部纳米结构的影响。用甘油单油酸酯 (GMO) 制备的立方纳米囊比用植物醇制备的立方纳米囊与更多的 F127 缔合。用植物醇和维生素 E 醋酸酯 (vitEA) 的混合物制备的六方纳米囊与它们缔合的 F127 比植物醇立方纳米囊多。用鲨肝醇制备的六方纳米囊与植物醇:vitEA 基六方纳米囊和 GMO 基立方纳米囊相比，与它们缔合的 F127 较少。这表明，粒子的组成脂质和粒子的内部纳米结构都对 F127 与溶致液晶纳米结构粒子的缔合有影响。
