Aggregation behavior of sodium salt of ibuprofen with conventional and gemini surfactant

Aggregation behavior of sodium salt of ibuprofen (SIBU) and conventional surfactant - hexadecyltrimethylammonium bromide (HTAB) along with gemini surfactant - 1,6-Bis(N-hexadecyl-N,N-dimethylammonium)hexane dibromide (16-6-16) mixtures have been carried out at 298.15 K by employing tensiometric method. Different hypothetical models for instance, Clint, Rubingh, as well as, Rosen was engaged to obtain the nature of interaction amid the drug and surfactant in the solution and at the interface. Gemini surfactant is more effective in decreasing the critical micelle concentration (cmc) of the drug as compared to conventional surfactant. The mixed systems show lower cmc value in comparison to ideal cmc (cmcid) value representing the non-ideal behavior of present solution mixture of drug and surfactant. The nonideality of the mixed system also stated in terms of the interaction parameter (βm/βσ). Additional parameters concerning tensiometry methods, for instance, micellar mole fraction of mixed micelles/mixed interface (X1m/X1σ), area occupied per amphiphile molecule (Amin), surface excess concentration (Γmax), etc. were computed and discussed one by one. Packing parameters were also evaluated and discussed. The ΔGom and ΔGoads values for every studied solution were achieved to be negative i.e., micellization, as well as adsorption processes, are energetically favorable and the value of ΔGoads were more negative than their corresponding ΔGom, showing that work is done in transferring the amphiphilic monomers from interface to the micellar stage across the aqueous solution to form micelles.