Aggregation Behavior and Micellization Thermodynamics of Cetyltrimethylammonium Bromide–Ofloxacin Mixture in Glucose and Urea Media

Abstract

—This research utilizes conductivity measurements to provide insight into the temperature-driven micellization of cetyltrimethylammonium bromide (CTAB) with the antibiotic drug ofloxacin (OFX), while also highlighting the impact of urea and glucose on the aggregation of the CTAB–OFX combination. The addition of OFX facilitated the micellization of CTAB. Glucose, via hydrogen bonding with water molecules, makes the solvent environment less favorable for the hydrophobic segments of the CTAB and urea, by diminishing hydrophobic interactions, impeding micelle formation, hence elevating the CMC of the CTAB–OFX mixture. The interaction between CTAB and OFX has been characterized employing physicochemical variables (counterion dissociation, α; and CMC) and thermodynamic parameters (entropy of micellization, ΔS\(_{m}^{0}\); Gibbs energy of micellization, ΔG\(_{m}^{0}\); and enthalpy of micellization, ΔH\(_{m}^{0}\)). The spontaneity of micellization in the CTAB–OFX combination in both water and urea/glucose conditions is depicted by the negative ΔG\(_{m}^{0}\) results. Negative ΔS\(_{m}^{0}\) and ΔH\(_{m}^{0}\) values indicate the predominance of H-bonding, while positive ΔS\(_{m}^{0}\) and ΔH\(_{m}^{0}\) values denote a hydrophobic relationship. The CTAB–OFX combination’s +ΔS\(_{m}^{0}\) and –ΔH\(_{m}^{0}\) results reveal that both hydrophobic and electrostatic interactions are most probably engaged in the OFX-induced micellization of CTAB. The findings provide essential insights for researchers seeking to enhance parameters such as temperature, surfactant concentration, and the additive (urea and glucose) content, thereby augmenting the efficacy and resilience of drug delivery systems.