Elution of six antibiotics bonded to polyethylene vascular grafts sealed with three proteins

The elution of six antistaphylococcal antibiotics from vascular polyethylene grafts sealed with albumin, gelatin, or collagen were studied in an in vitro system. The antibiotics tested were pefloxacin, vancomycin, teicoplanin, fusidic acid, pristinamycin, and rifampicin. The grafts were impregnated by simple soaking in antibiotic (1 mg/ml). The data were fitted to an exponential model and antibiotic half-lives (t(1/2)) were calculated from the regression lines. Ah the antibiotics tested were bound to the protein sealants. Antibiotic release varied with the type of antibiotic and the sealant. Rifampicin was eluted most slowly, particularly with albumin- and gelatin-sealed grafts, with t(1/2) at 4-5.5 hr and antibiotic activity was still found at 48 hr. The glycopeptides were also eluted more slowly fi om albumin or gelatin sealant than from collagen. Although large quantities of glycopeptides were initially bound, they were quickly eluted (t(1/2) = 30-44 min) and there was no residual antibiotic activity at 24 hr. Pefloxacin, pristinamycin, and fusidic acid bound to collagen or gelatin sealants were the most rapidly eluted, with t(1/2) of 3-14 min, but they were eluted more slowly from albumin-sealed grafts, with t(1/2) of 22-90 min. In vitro studies can be useful for evaluating the binding of antibiotics to protein-sealed grafts before animal experiments or human testing. (C) 1996 Academic Press