Takegami Shigehiko, Kitamura Keisuke, Kawada Hiroto, Matsumoto Yu, Kitade Tatsuya, Ishida Hiroharu, Nagata Chieyo
Kyoto Pharmaceutical University, Kyoto, Japan.
Chem Pharm Bull (Tokyo). 2008 Aug;56(8):1097-102. doi: 10.1248/cpb.56.1097.
A new lipid nano-emulsion (LNE) was prepared from soybean oil and phosphatidylcholine (PC) employing two cosurfactants, sodium palmitate (PA) for reduced droplet size and sucrose palmitate (SP) for stability enhancement. The mean droplet size of LNEs prepared at a PA/PC (w/w) ratio of larger than 1/10 was found to be ca. 50 nm by dynamic light scattering and atomic force microscopy. However, during the 12-month storage, the PA/PC (1/10)-LNE showed an increase in mean droplet size and broadening of the droplet size distribution due to coalescence of the LNE particles. In a saline solution, the coalescence proceeded very rapidly, i.e., the mean droplet size increased to more than 150 nm within 0.5 h. To suppress the coalescence of LNE particles, four sucrose fatty acid esters of different chain lengths were examined as candidate cosurfactants. The results showed that PA/SP/PC (1/4/10)-LNE could maintain a mean droplet size around 50 nm for 12 months. In a saline solution, the mean droplet size could be maintained within 100 nm even after 24 h. Slight formation of flocculation in the LNEs depending on the storage period was suggested by measurement of the 31P nuclear magnetic resonance line width of the LNEs.
采用两种助表面活性剂制备了一种新型脂质纳米乳剂（LNE），其中用棕榈酸钠（PA）降低液滴尺寸，用蔗糖棕榈酸酯（SP）增强稳定性，原料为大豆油和磷脂酰胆碱（PC）。通过动态光散射和原子力显微镜发现，当PA/PC（w/w）比大于1/10时制备的LNE的平均液滴尺寸约为50 nm。然而，在12个月的储存期内，PA/PC（1/10）-LNE由于LNE颗粒的聚结，平均液滴尺寸增加，液滴尺寸分布变宽。在盐溶液中，聚结进行得非常迅速，即在0.5小时内平均液滴尺寸增加到150 nm以上。为了抑制LNE颗粒的聚结，研究了四种不同链长的蔗糖脂肪酸酯作为候选助表面活性剂。结果表明，PA/SP/PC（1/4/10）-LNE在12个月内可以将平均液滴尺寸维持在50 nm左右。在盐溶液中，即使在24小时后，平均液滴尺寸也可以维持在100 nm以内。通过测量LNE的31P核磁共振线宽表明，LNE中会根据储存时间轻微形成絮凝。
