LAUSR

Abstract The interaction between ceftriaxone sodium trihydrate (CFT) drug and surfactants such as tetradecyltrimethylammonium bromide (TTAB), Triton X-100 (TX-100), and Tween-80 (TW-80) was studied under various conditions by using three different physico-chemical methods. CFT is used for the treatment of lung infections, urinary bladder, bone, joint, gonorrhea, meningitis, etc., depending on the bacterial disease. Different parameters such as critical micelle concentration (cmc), various thermodynamic parameters for drug-TTAB aqueous mixtures in an ethanol solvent, etc., have been measured. The varying cmc value of TTAB with the addition of CFT in the TTAB solution signifies the existence of interaction between TTAB and CFT. This interaction and the cmc values of mixtures of drug and TTAB, depend upon the employed concentration of alcohols and the system temperature. Negative values of the standard free energy of micellization (ΔGom), were obtained for all cases; this indicates the spontaneous nature of the currently employed system of drug and surfactant mixtures. Parameters such as heat capacity (ΔC°p.m.) and various transfer energies were also evaluated and are discussed. In the case of the cloud point (CP) method the phase separation of TX-100 in an aqueous system was intensified in the presence of CFT. The standard free energy of clouding (ΔGoc), for the (CFT-TX-100) system was evaluated and found to be positive; this indicates the non-spontaneous characteristic of this clouding action. For the system of CFT-TW-80 mixtures, the value of the binding constant (Kb) is dependent on temperature, and the types of solvent of different composition in both aqueous and alcoholic mediums. Therefore, hydrogen bonding and electrostatic interactions are important due to the binding interaction between CFT and TW-80.