Antibiotic-impregnated fibrin glue in ocular surgery: in vitro antibacterial activity.

A strategy to reduce postoperative ocular infections might consist in maintaining a high antibiotic concentration in the eye by using a topical slow-release drug formulation. Fibrin glue is widely used in ocular surgery. Vancomycin, teicoplanin, cephalothin and gentamicin were added to a 500 IU/ml thrombin solution, their concentrations in 1 g fibrin glue being 500 microg for vancomycin and 400 microg for the other drugs. The in vitro antibacterial activity of antibiotic-impregnated fibrin glue was evaluated against a recent clinical isolate of Staphylococcus epidermidis. Moreover the antibiotic elution from fibrin discs in saline was assayed for up to 96 h. Fibrin glue properties were maintained when thrombin was reconstituted with a CaCl2 solution additioned with the antibiotics tested. All antibiotic fibrin mixtures exhibited good antistaphylococcal activity immediately after the preparation. A prolonged inhibition (4 days) of S. epidermidis growth was observed with teicoplanin discs. Gentamicin and teicoplanin levels were higher than those of the other antibiotics. The results suggest that the fibrin glycopeptide and/or gentamicin mixtures can be used, both prophylactically and therapeutically, in ocular surgery.