Physico-chemical parameters for the assembly of moxifloxacin hydrochloride and cetyltrimethylammonium chloride mixture in aqueous and alcoholic media

Abstract

The aggregation behavior of the mixture of cetyltrimethylammonium chloride (CTAC), a cationic surfactant, and moxifloxacin hydrochloride (MFH), a fourth-generation fluoroquinolone antibiotic drug, has been studied using the conductivity technique in aqueous and alcoholic (EtOH, 1-PrOH, and 2-BuOH) media. The study was performed at several temperatures between 298.15 and 323.15 K at 5 K intervals. The assembly has been characterized by evaluating the micellar parameters, such as the critical micelle concentration (CMC) and the counter ion binding (β), of the CTAC + MFH mixture. The values of the CMC for the assembly of the CTAC + MFH mixture were reliant on the composition of alcohols in the mixed solvents and the temperature. The CMC values of the CTAC + MFH mixture increased with increasing temperature; that is, assembly was delayed by increased temperature. The micellization of the CTAC + MFH mixed system was delayed in alcoholic media. The observed -ΔGm0 values for the association of the CTAC + MFH mixed system demonstrated a spontaneous aggregation process under all study conditions. Based on the -ΔHm0 and +ΔSm0 values, the association of the CTAC + MFH mixture is exothermic and the interaction forces acting between the CTAC and MFH species are hydrophobic, ion–dipole, and electrostatic interactions. The transfer properties and enthalpy–entropy compensation were also assessed and described comprehensively.