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Updated: Jul 11, 2026

Self-Nanoemulsification of Healthy Oils to Enhance the Solubility of Lipophilic Drugs
Published on: July 27, 2022
Degree of counterion binding on water in oil microemulsions
E Fernández1, L García-Río, P Rodríguez-Dafonte
1Departamento de Química Física, Facultad de Química, Universidad de Santiago de Compostela, 15782 Santiago, Spain.
Abstract:
An ion-exchange process has been used to prepare HOT from NaOT (sodium bis(2-ethylhexyl)sulfosuccinate), where the Na(+) counterion has been replaced by H(+). The acidity function, H(0), of the aqueous core of HOT-based microemulsions decreases with W from H(0) approximately 0.6 at W>20 to H(0)=-1.4 at W=2. On the basis of the H(0) acidity function of the aqueous core and the dependence of H(0) on acid concentration, we have been able to determine the degree of counterion binding (beta) in microemulsions with a value of beta approximately 0.92 which is practically independent of the water content of the system.
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