Silver ciprofloxacin (CIPAG): a successful combination of chemically modified antibiotic in inorganic-organic hybrid.

The new silver(I) ionic, water soluble, compound {[Ag(CIPH) ₂ ]NO ₃ ∙0.75MeOH∙1.2H ₂ O} (CIPAG) was obtained by reacting silver(I) nitrate with the antibiotic ciprofloxacin (CIPH). The complex was characterized by m.p., mid-FT-IR, ¹ H-NMR, UV-Vis spectroscopic techniques. The crystal structures of both CIPAG and the hexahydrated neutral free drug {[CIPH]∙6(H ₂ O)} (2) were characterized by X-ray crystallography. Two neutral ligands are datively bonded to the metal ion through the piperidinic nitrogen atoms forming a cationic {[Ag(CIPH) ₂ ] ⁺ } counter part which is neutralized by a nitrate group. The antibacterial effect of CIPAG and the commercially available hydrochloric salt of the antibiotic ({[CIPH ₂ ⁺ ]∙Cl ^- } (3)) were tested against the bacterial species Pseudomonas aeruginosa (PAO1), Staphylococcus epidermidis (St. epidermidis) and Staphylococcus aureus (St. aureus) by the mean of minimum inhibitory concentration, minimum bactericidal concentration and their inhibitory zone (IZ). The influence of CIPAG and 3 against the formation of biofilm of PAO1 or St. aureus was also evaluated by mean of biofilm elimination concentration. The IZ caused by CIPAG which has been loaded in poly-hydroxyethylmethacrylate, is determined. The genotoxicity of CIPAG and 3 is tested in vitro against normal human corneal epithelial cells (HCET cells), by the presence of micronucleus in HCET cells and in vivo by mean of Allium cepa test.