Interactions and Solubilization of Poorly Soluble Drugs in Aerosol‐OT Micelles

Abstract

Absorption spectroscopy, conductivity, and surface tension measurements were carried out at 298 K to study the solubilization of poorly soluble drugs sulfamethoxazole (SMX) and trimethoprim (TMP) in Aerosol‐OT (AOT) micellar media. The binding constants of SMX and TMP to AOT micelles were determined by applying the Benesi–Hildebrand equation. A comparison of the binding constants indicates that the binding tendency of TMP with AOT micelles is higher than that of SMX. To better analyze the incorporation of drugs into anionic AOT micellar media, surface tension measurements were performed in the presence of SMX and TMP in aqueous media. The influence of TMP and SMX on the surface properties of AOT was determined using the Gibbs Adsorption Isotherm. Changes in the surface properties of AOT determined by surface tension measurements in the presence of drugs are in good agreement with the binding constants determined spectrophotometrically. Calculated surface parameters indicate higher incorporation of TMP with AOT than that of SMX. Comparison of the aqueous solubility of TMP and SMX with micellar media indicated solubility enhancements for both poorly soluble drugs. A special attempt was made to highlight simultaneous interactions of TMP and SMX with AOT using both surface tension and conductometric measurements that can be used to determine counterion‐binding parameters.

Self-assembling of surface active drug amitriptyline hydrochloride in association with additives: Role of surface activity in the pharmaceutical applications

“…The CMC of amphiphilic drug AMT was determined by measuring a change in the surface tension and electrical conductivity with various concentrations of AMT in water and in the presence of additives as described in detail previously (Florence and Atwood 1998;Gokturk and Aslan, 2014;Gokturk and Tamer, 2018). The CMC of AMT obtained through different measurements are consistent with the values in literature (3.48x10 -2 mol/L) (Schreier et al, 2000).…”

“…Amin (Å 2 molecule -1 ) is determined from the value of max by the Eq.2. (NA is the Avogadro constant); (Florence and Atwood 1998;Gokturk and Tamer, 2018).…”