Quantitative evaluation of sparfloxacin binding to urological catheter surfaces

Our aim was to apply high-performance liquid chromatography method for quantitative evaluation of the total amount of sparfloxacin (SPA) immobilized on the surface of the antimicrobial urological catheters. The amounts of SPA bound to catheter were determined indirectly on the basis of the differences in SPA concentrations before and after the immobilization process (they have been shown to vary from 0.11 to 5.66 mg/g of catheter). We estimated the immobilization yield, which altered from 14% to 70% depending on the SPA concentration used. As in vitro release studies show, the antibiotic binds to the catheter matrix in two modes: relatively stable covalent bond and weak non-covalent bond. Antibacterial activity of the modified catheter samples with SPA was controlledby using the zone of inhibition test against gram positive and gram negative bacteria.