Conductivity Study on the Impact of Ethanol and Temperature on SDS Aggregation in the Presence of Promethazine Hydrochloride

Abstract

This study investigates the impact of ethanol (EtOH) content and temperature on the PMH + SDS sy tem, focusing on counterion binding, degree of ionization, critical micelle concentration (CMC), and thermodynamic properties. The addition of EtOH is found to enhance and delay the assembly of the PMH + SDS mixture, influencing micelle formation. The CMC values decrease with increasing EtOH concentration, indicating altered interactions between water molecules and SDS. Temperature fluctuations also affect the CMC, with an increase observed as temperature rises. Thermodynamic analysis reveals o consistently negative Gibbs free energy (  G m ) values, suggesting the spontaneous and 0 exothermic nature of micellization facilitated by PMH. Enthalpy change (  H m ) values 0 indicate hydrophobic interactions, while positive entropy change (  S m ) values signify enhanced water molecule randomness in the micelle's core. The presence of aqueous EtOH is found to influence hydroph bic interactions between SDS and PMH, emphasizing the role of additives in altering the surfactant-drug mixture's hydration and structure. Overall, this study provides valuable insights into the complex the modynamics governing mixed surfactant systems.