Colloidal properties of amiodarone in water at low concentration.

Amiodarone aqueous systems at concentrations C<or=3mg/mL were studied with different techniques (conductivity, solubility, ion-selective electrodes, pH, viscosity, polarizing microscopy, computational simulation, electron microscopy and fluorescence at various temperatures. The Krafft point (T(K)=70.6 degrees C) was determined. A partial phase diagram was plotted showing the critical micelle concentration (CMC) dependence on temperature, the solubility and a transition between a coacervate and an unstable gel below T(K) as a function of temperature. The nature of aggregates below T(K) at different concentrations was determined. Micellization is an entropy-driven process which is probably caused by a strong dehydration of the amiodarone backbone on micellization. CMC, micelle aggregation number and T(K) given in earlier literature were misinterpreted in the original articles and are re-interpreted in this work.
(Copyright 2009 Elsevier Inc. All rights reserved.)