Welin-Berger K, Bergenståhl B
AstraZeneca, SE-151 85, Södertälje, Sweden.
Int J Pharm. 2000 May 10;200(2):249-60. doi: 10.1016/s0378-5173(00)00395-1.
The stability of submicron emulsions of different local anesthetic/analgesic substances was investigated in the presence and absence of different hydrophobic excipients (ripening inhibitors). Ostwald ripening was believed to be the underlying mechanism for the instability of these emulsions. In the absence of ripening inhibitors, the mean droplet size of the emulsions increased from 100 nm to about 4-5 microm within an hour of manufacture. The addition of a small amount of a second component of lower solubility to the disperse phase decreased the rate of Ostwald ripening, producing good stability of the emulsions. The efficiency of the ripening inhibitors was directly proportional to their solubility in the disperse phase, i.e. the water. The lower the solubility, the more effective the stabilization of the emulsions. The experimentally observed rates of increase in droplet size in the emulsions were closely correlated with those predicted according to the Liftshitz-Slezov-Wagner (LSW) theory.
在有和没有不同疏水辅料（熟化抑制剂）的情况下，研究了不同局部麻醉/镇痛物质的亚微米乳剂的稳定性。奥氏熟化被认为是这些乳剂不稳定的潜在机制。在没有熟化抑制剂的情况下，乳剂的平均液滴尺寸在制备后一小时内从100纳米增加到约4-5微米。向分散相中添加少量溶解度较低的第二组分降低了奥氏熟化速率，使乳剂具有良好的稳定性。熟化抑制剂的效率与其在分散相即水中的溶解度成正比。溶解度越低，乳剂的稳定效果越有效。实验观察到的乳剂中液滴尺寸增加速率与根据 Lifshitz-Slezov-Wagner（LSW）理论预测的速率密切相关。
