Kogan Anna, Aserin Abraham, Garti Nissim
Casali Institute of Applied Chemistry, The Institute of Chemistry, E. Safra Campus, Givat Ram, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel.
J Colloid Interface Sci. 2007 Nov 15;315(2):637-47. doi: 10.1016/j.jcis.2007.06.087. Epub 2007 Jul 31.
Solubilization capacity and structural transformations in nonionic microemulsions characterized by a large continuous isotropic region forming dilutable self-assembled nanodroplets containing solubilized carbamazepine, were studied along dilution lines 73 and 82 (70 and 80 wt% surfactant and 30 and 20 wt% of oil phase, respectively). The preparations were based on pharma-grade ingredients, water, R-(+)-limonene, ethanol, propylene glycol, and Tween 60. Solubilization capacity (SC) of the drug was dependent on the microstructure of the microemulsion and on the surfactant-to-oil phase weight ratio. The SC in the concentrate (reversed micelles) was 15 times higher than its solubility in the oil. Transition of the W/O microemulsion to a bicontinuous phase and to O/W droplets were indentified by electrical conductivity, viscosity, SAXS, and SD-NMR measurements. Once the system is diluted to 90 wt% aqueous phase, the SC is 10 and 16-fold higher, along dilution lines 73 and 82, respectively, than in pure water. Being solubilized, carbamazepine serves as a cosurfactant therefore it affects the curvatures of the microstructures and consequently the boundaries of the structural regions and the transition points between the different phases. Dilutable microemulsions are promising new carbamazepine vehicles for oral intake.
研究了以大的连续各向同性区域为特征的非离子微乳液的增溶能力和结构转变，该区域形成了含有增溶卡马西平的可稀释自组装纳米液滴，沿着稀释线73和82（分别为70 wt%和80 wt%的表面活性剂以及30 wt%和20 wt%的油相）进行研究。制剂基于药用级成分、水、R-(+)-柠檬烯、乙醇、丙二醇和吐温60。药物的增溶能力（SC）取决于微乳液的微观结构以及表面活性剂与油相的重量比。浓缩物（反胶束）中的SC比其在油中的溶解度高15倍。通过电导率、粘度、小角X射线散射（SAXS）和自旋扩散核磁共振（SD-NMR）测量确定了W/O微乳液向双连续相和向O/W液滴的转变。一旦系统稀释至90 wt%的水相，沿着稀释线73和82，SC分别比在纯水中高10倍和16倍。卡马西平被增溶后作为助表面活性剂，因此它会影响微观结构的曲率，进而影响结构区域的边界以及不同相之间的转变点。可稀释微乳液是有前景的新型卡马西平口服给药载体。
