Fernández M S
Biochim Biophys Acta. 1980 Mar 27;597(1):83-91. doi: 10.1016/0005-2736(80)90152-2.
The formation of micelles of the local anesthetic tetracaine hydrochloride in aqueous phosphate buffer solution of pH 6.5 and ionic strength (I) 0.10 was examined at 22 degrees C by surface tension and using the fluorescent indicators perylene (peri-dinaphthalene) and 8-anilino-1-naphthalene sulfonic acid, sodium salt (ANS). The critical micelle concentration was located at 0.069, 0.071 and 0.063 M by measurements of surface tension, perylene solubilization and enhancement of ANS fluorescence, respectively. In contrast to other cationic surfactants, the anesthetic monomer did not show evidence of forming a fluorescent molecular complex with ANS under the experimental conditions of this study. The formation of micelles by tetracaine-HCl showed a pronounced effect on lipid membranes by inducing an abrupt decrease in the scattered light of egg lecithin liposomes at an anesthetic concentration roughly similar to its critical micelle concentration. This optical behaviour is characteristic of liposome damage and can be interpreted to mean that the lipids become solubilized into tetracaine-HCl micelles. The ability of this local anesthetic to form micelles can be taken as a manifestation of the same hydrophobic forces that lead to partitioning of the drug into membranes.
在22℃下，通过表面张力并使用荧光指示剂苝（并二萘）和8-苯胺基-1-萘磺酸（钠盐，ANS），研究了盐酸丁卡因（一种局部麻醉剂）在pH值为6.5、离子强度（I）为0.10的磷酸盐缓冲水溶液中胶束的形成。通过表面张力测量、苝增溶作用以及ANS荧光增强，测得临界胶束浓度分别为0.069 M、0.071 M和0.063 M。与其他阳离子表面活性剂不同，在本研究的实验条件下，麻醉剂单体未显示出与ANS形成荧光分子复合物的迹象。盐酸丁卡因形成胶束对脂质膜有显著影响，在麻醉剂浓度大致与其临界胶束浓度相近时，会导致卵磷脂脂质体的散射光突然降低。这种光学行为是脂质体损伤的特征，可解释为脂质溶解到盐酸丁卡因胶束中。这种局部麻醉剂形成胶束的能力可被视为导致药物分配到膜中的相同疏水作用力的一种表现。
