Influence of additives on the interaction of antidepressant drug with TX-165 surfactant: Surface tension and FTIR analyses

• Imipramine hydrochloride (IMP) and TX-165 interaction were performed using surface tension and FTIR methods. • Effects of NaCl/urea were evaluated on surface property of IMP + TX-165 mixtures. • Higher negative interaction parameters ( β σ ) denoted interaction between components. • Negative Gibbs adsorption energy ( Δ G a d s o ) illustrating that monomers adsorb spontaneously. • FTIR analysis also exposed the fine interaction among constituents. Surfactant is a principal substance entity in drug formulation that binds to drug monomers. Herein, interaction between the antidepressant drug imipramine hydrochloride (IMP) and TX-165 surfactant were carried out using surface tension and FTIR techniques. Through the surface tension measurements, we were able to discern what was happening at the interface by evaluating the interface parameters. The effect of NaCl and urea of fixed concentration were also evaluated on surface behavior of mixtures of IMP + TX-165 using surface tension method. First component (TX-165) composition at the interface ( X 1 σ ) in the case of IMP + TX-165 mixture is ranges from 0.7533 to 0.9522 over the entire employed mole fraction ( α 1 ) of TX-165, viewing the high composition of TX-165 compared with IMP at the mixed surface (IMP + TX-165). Higher attained negative interaction parameters ( β σ ) values denoted the valuable interaction between employed components at the interface. The surface excess concentration ( Γ max ) value of TX-165 is more than the Γ max value of IMP, showing that TX-165 privileged a compressed/tightly packed layout at the interface, means displayed higher surface activity than IMP. Mixture pC 20 values were noticeably larger than pure IMP, together with their value enhanced via raising α 1 and became above the pC 20 values of both employed pure constituents at the highest employed α 1 . Gibbs energy of adsorption ( Δ G a d o ) pure and mixed employed amphiphiles studied were attained negative, suggesting the formation of spontaneous mixed interfaces. FTIR analysis exposed that the wavelength shifting in constituents’ mixture arose compared with singular constituent making clear the interaction among constituents. An effective delivery of antidepressants could be achieved with the use of TX-165 surfactant, according to the results of the present study.