Interaction of promethazine hydrochloride with TX-165 in aqueous, NaCl and urea media: a tensiometry and FTIR analysis

An experiment using surface tension was conducted to investigate the interactions of promethazine hydrochloride (PMT), with TX-165, at the interface in different ratios and solvents (water/50 mmol/kg NaCl, and 500 mmol/kg urea) at 298.15 K. A thorough FTIR study of the employed pure and mixed system was also conducted in the aqueous solution. PMT is a medication employed to manage and cure allergic conditions. Usually, NaCl media improved the surface properties of singular and mixed components over aqueous media, resulting in synergistic/attractive interactions among ingredients. TX-165’s composition at mixed monolayer (X1σ), surface excess concentration (Γmax), pC20, activity coefficient, and so on were evaluated. The achieved activity coefficient values are attained below one in each case, indicating the attractive interactions amongst ingredients. A negative Gibbs energy of adsorption (ΔGadso) was obtained all through, indicating spontaneity in the process. A negative excess free energy (ΔGexσ) was found at the mixed interface of PMT + TX-165, showing a higher surface stability of mixed monolayer than pure component monolayer. FTIR spectroscopy is used to study the spectrum of single and mixed amphiphiles to validate the interaction between PMT and TX-165. This study suggested that TX-165 surfactant might behave as an able antidepressant drug delivery agent.