Diffusion of antibiotics from a polytetrafluoroethylene-benzalkonium surface.

The ability to bond antibiotics non-covalently to polytetrafluoroethylene surfaces was evaluated in an animal model. Grafts soaked or bonded in (14)C-penicillin were placed in subcutaneous pockets in rats and harvested at various time intervals. The amount of antibiotic present on grafts and in local tissue were evaluated by liquid scintillation counting. Antibiotic bonding resulted in higher concentrations of antibiotic present on the graft at implantation. Diffusion of antibiotics from the graft into surrounding tissues was also slowed by the bonding process. However, all grafts retained minimal activity at the end of 24 hours. The possibility of managing vascular prostheses with antibiotic bonding and local antibiotic irrigation is raised.