Study on mixed association behaviour of sodium salt of ibuprofen (IBF) and TX-165 mixture in different media

Sodium salt of ibuprofen (IBF) drug, a non-steroidal anti-inflammatory, and TX-165 nonionic surfactant mixture with diverse mole fraction (α₁) of TX-165 at a temperature of 298.15 K was investigated by the tensiometry method to evaluate dissimilar physico-chemical characteristics. UV–visible spectroscopy was also utilized to determine the interactions amongst IBF and TX-165. The interaction amongst IBF and TX-165 was also assessed employing 100 mmol·kg⁻¹ NaCl and 500 mmol·kg⁻¹ urea solvents other than the aqueous solution. Ideal cmc (cmc^id) value of mixed systems (IBF + TX-165) achieved by tensiometric measurements was remarkably over the critical micelle concentration (cmc) value. Accordingly, it was validated that IBF and TX-165 interact well, and interaction also rises due to an increase in TX-165’s α₁. The cmc values for entire singular and mixtures of urea media were higher compared with those for aqueous system, while in NaCl media, they were much lower than those for aqueous systems. Clint, Motomura, Maeda, and Rubingh, hypothetical models have been applied to reveal aggregation and thermodynamic properties. Employed ingredients activity coefficients for micellar solutions were always under one, demonstrating the nonideal behaviour together with intermolecular interactions amongst ingredients. As a result of the obtained excess free energy being negative in all cases, the mixed micelles have more stability than their singular ingredients’ micelles. Interaction amongst IBF and TX-165 with each other was also attained well through a UV–visible study. According to the results, TX-165 has the potential to be an applicable ingredient for the delivery of drugs.

Graphical Abstract