Westesen K, Wehler T
Institute of Pharmaceutical Technology, Braunschweig, Germany.
J Pharm Sci. 1992 Aug;81(8):777-86. doi: 10.1002/jps.2600810812.
Photon correlation spectroscopy, nuclear magnetic resonance spectroscopy, electron microscopy, and small-angle X-ray scattering were used for the structural characterization of a model oil-in-water emulsion containing particles in the submicrometer size range. Additionally, small-angle X-ray diffraction, wide-angle X-ray diffraction, and differential scanning calorimetry were applied to raw materials and to binary mixtures. The majority of emulsion droplets have the characteristic of an ideal emulsion droplet, that is, a liquid lipid core covered by an emulsifier monolayer. However, the system contains a certain excess of emulsifier. Particles with bi- and/or oligolayer structures can be deduced. Double-emulsion droplets were detected. Large unilamellar vesicles were not found; however, the existence of small unilamellar liposomes (also referred to as small unilamellar vesicles or SUVs) seems likely. The proportion of all small nonmonolayer structures was quantified by nuclear magnetic resonance spectroscopy. No mixed micellar structures were detectable. Lysophospholipids were not detected in the aqueous phase, indicating their predominant incorporation into the emulsifier layers. Water-soluble phospholipid degradation products were found in the water phase. The existence of at least several monolayers of phospholipids does not seem to be a prerequisite for a stable soybean oil-in-water emulsion, in general.
采用光子相关光谱法、核磁共振光谱法、电子显微镜和小角X射线散射对一种含有亚微米尺寸颗粒的水包油型乳液模型进行结构表征。此外，还对原材料和二元混合物进行了小角X射线衍射、广角X射线衍射和差示扫描量热法分析。大多数乳液滴具有理想乳液滴的特征，即由乳化剂单层覆盖的液态脂质核。然而，该体系含有一定量过量的乳化剂。可以推断存在具有双层和/或多层结构的颗粒。检测到了双乳液滴。未发现大单层囊泡；然而，小单层脂质体（也称为小单层囊泡或SUV）似乎有可能存在。通过核磁共振光谱法对所有小的非单层结构的比例进行了定量。未检测到混合胶束结构。在水相中未检测到溶血磷脂，表明它们主要掺入了乳化剂层中。在水相中发现了水溶性磷脂降解产物。一般来说，至少几层磷脂的存在似乎不是稳定的大豆水包油乳液的先决条件。
