Physico-chemical study of the interaction of ceftriaxone sodium trihydrate antibiotic drug with surfactants in absence/presence of different additives at different temperatures

This book presents a comprehensive physico-chemical investigation of the interactions between the third-generation cephalosporin antibiotic ceftriaxone sodium trihydrate and selected cationic and nonionic surfactants in aqueous media. Emphasizing both fundamental understanding and pharmaceutical relevance, the study systematically explores micellization, clouding phenomena, and drug–surfactant binding under the influence of temperature variation and the presence of diverse additives. Using conductivity measurements, the book examines the micellization behavior of cetylpyridinium chloride in the presence of ceftriaxone sodium, highlighting the effects of drug concentration, electrolytes, hydrotropes, polyols, pH, and temperature on critical micelle concentration, degree of ionization, and counterion binding. The results demonstrate how different additives and thermal conditions either promote or hinder micelle formation, providing insight into the balance between hydrophobic and electrostatic interactions within mixed drug–surfactant systems. The clouding behavior of the nonionic surfactant Triton X-100 in the presence of ceftriaxone sodium is analyzed in detail through cloud point measurements. The influence of inorganic salts, organic electrolytes, hydrotropes, and polyols on phase separation is systematically evaluated. Thermodynamic parameters associated with clouding reveal the spontaneity, enthalpic nature, and entropy contributions of the phase separation process, offering a deeper understanding of solute–solvent and solute–solute interactions in nonionic surfactant systems. The book further investigates drug–surfactant binding using UV–Visible spectroscopic techniques, with binding constants determined from Benesi–Hildebrand analysis. The temperature dependence of binding provides valuable thermodynamic insight, indicating the dominant molecular forces involved in complex formation between ceftriaxone sodium and Triton X-100. Throughout the book, detailed thermodynamic analyses including Gibbs free energy, enthalpy, entropy changes, and enthalpy–entropy compensation are used to interpret experimental observations and elucidate the molecular mechanisms governing aggregation, phase separation, and binding phenomena. The work highlights the roles of hydrophobic interactions, electrostatic forces, ion–dipole interactions, hydrogen bonding, and π–π interactions in determining system behavior. Overall, this book serves as a valuable reference for researchers, postgraduate students, and professionals in physical chemistry, colloid and interface science, and pharmaceutical sciences. By integrating experimental rigor with thermodynamic interpretation, it provides important insights into drug–surfactant interactions and their relevance to pharmaceutical formulation, drug delivery, and biomimetic systems.