Ferrit Mónica, del Valle Carmen, Martínez Fernando
Departmant of Physical-Chemistry, Faculty of Pharmacy, University of Granada, Campus Cartuja s/n, 18071 Granada, Spain.
Eur J Pharm Sci. 2007 Jul;31(3-4):211-20. doi: 10.1016/j.ejps.2007.03.011. Epub 2007 Apr 3.
In this research, the effects of micellar systems on alkaline hydrolysis reactions of acetylsalicylic acid (ASA) and triflusal (TFL) were found to be dependant upon the surfactant charge within the micelle. In cationic micelles, there is a catalytic effect at low concentrations of surfactant. However, this reaction is inhibited at higher surfactant concentrations. In anionic micelles, a catalytic effect occurs, while in zwitterionic and non-ionic micelles there is an inhibitory effect. Such reactions are attributable to changes in reactants on the micellar surface, or to the fact that both reactants are found in different microenvironments. The pseudophase (PS) and ion-exchange (PPIE) models were found to be consistent with the experimental result. Furthermore, the association constants for both drugs could be determined together with micellar rate constants in heterogeneous media.
在本研究中，发现胶束体系对乙酰水杨酸（ASA）和曲氟柳（TFL）碱性水解反应的影响取决于胶束内表面活性剂的电荷。在阳离子胶束中，低浓度表面活性剂时有催化作用。然而，在较高表面活性剂浓度下该反应受到抑制。在阴离子胶束中，会产生催化作用，而在两性离子和非离子胶束中则有抑制作用。此类反应归因于胶束表面反应物的变化，或者两种反应物处于不同微环境这一事实。发现假相（PS）和离子交换（PPIE）模型与实验结果一致。此外，两种药物的缔合常数以及非均相介质中的胶束速率常数均可确定。
