Conductometric Study of Influence of Urea on Interactions of Sodium Dodecyl Sulfate with Cefradine

Interaction of anionic surfactant, sodium dodecyl sulfate (SDS) with antibiotic drug cefradine monohydrate (CFD) were carried out in H2O/low concentration urea medium through conductivity measurement. The variation of critical micelle concentration (CMC) of SDS with the addition of drug (CFD) discloses the presence of interaction between SDS and CFD. The CMC of SDS were attained to dwindle in the presence of CFD. The attained values of CMC show U-shaped behavior as a function of temperature. The effect of urea on the CMC values was observed to be reduced as compared to aqueous medium which is different from the most of the reports mentioned in the literature. The estimated negative values of Gibbs free energy of micellization (Delta G(m)degrees) express that micellization is thermodynamically spontaneous within the entire systems investigated. The magnitudes of CFD mediated enthalpy of micellization (Delta Pi(m)degrees) as well as entropy of micellization (Delta S-m degrees) for SDS were achieved and clarified in details.