The nano-CuCl2.2H2O salt was prepared by the ball milling method. The association parameters for bulk and nano-CuCl2 salts in H2O are estimated at different temperatures using the conductivity method by applying the Fuoss–Shedlovsky equation and it was higher for nano-CuCl2 than bulk CuCl2 salt. The interaction between the cation (Cu2+) and ligand (ceftriaxone) in H2O was determined also by the conductometric method. Two stoichiometric complexes 1/2 and 1/1 (M/L) are estimated and follow the order Kf (1/1) > Kf (1 : 2) and ∆Gf (1/1) > ∆Gf (1/2) for (M : L) (in negative values) indicate the favorable of formation of (1/1) complex compared to the (1 : 2) complex. The Gibbs free energies change was increased in negative signs with increasing the temperature. The antimicrobial activities of CFT, bulk Cu-CFT complex, and nano-Cu-CFT complex were studied on LB agar by the disc diffusion technique against clinical isolates of gram-negative bacteria (Klebsiella pneumonia and Pseudomonas aeruginosa) and Fungi (Candida albicans). It was observed that (CFT) has a higher zone of inhibition and antibacterial activity than that of bulk and nano-Cu-CFT complexes in Klebsiella pneumonia and Pseudomonas aeruginosa (gram-negative bacteria). The nano-Cu-CFT complex showed a higher clear zone of inhibition and antifungal activity against candida than bulk Cu-CFT complex while the absence of the inhibition zone in CFT, so nano-Cu-CFT complex, can be used as an antifungal drug.

The association and thermodynamic association parameters for CdBr 2 were determined by the conductometric method in pure water and in a mixture of water−ethanol (0.30 mass fraction of ethanol) at different temperatures. The values of ion pair association was also calculated and found that CdBr 2 in ceftazidime drug has greater values compared to that in the absence of ceftazidime. Also, the complex formation constants and thermodynamic parameters for complex formation between CdBr 2 with ceftazidime as a ligand were also determined by the conductometric method. From the interaction of CdBr 2 with ceftazidime, two stoichiometric complexes were obtained 1:1 and 1:2. The complex K f and ΔG f are greater in the case of 1:1 than that of 1:2 (CdBr 2 / ceftazidime) complexes in 0% ethanol and in 30% ethanol solvents indicating easier complex formation. The formation constants decreased with increased temperature. The negative values of ΔG f for complexation indicate the spontaneity of the complex formation process and that the spontaneity increased with temperature. The negative values of ΔH f show the exothermic nature of the complexation and indicate that the complexation processes are more favored at low temperatures. The ΔS f values for the complexation are positive, confirming that the complex formation is entropically favorable. Significance of the study is to give a lot of data which can be easily obtained for following the very toxic heavy metal cadmium ions.

T he solubility is one of the vital parameters to attain the specified concentration of the drug in circulation for the desired (anticipated) pharmacologic response. This work aimed to calculate ion-solvent interaction, the density of ethanol-water (EtOH-H2O) mixtures; the density of oxytetracycline (OTC) saturated solutions, different volumes of solvation (Van der Waals volume, molar volume and electrostriction volume and solvated radii (ro)) from solubility data. It was found that; the activity coefficient (γ_±) of OTC were decreased by increasing the EtOH content in (EtOH-H2O) mixture used and also the logγ_± decrease within the rise in temperature. The densities and also the molar volume of OTC decrease by increasing the quantitative ratio of EtOH and also was increased by rising in temperature. The electrostriction volumes and therefore the solvated radii (ro) of OTC are increased as the EtOH content increase and also are increased by the rise in temperature.