This invention describes a bioerodible fibrin material which is obtained by mixing fibrinogen and thrombin reconstituted or diluted with a particular high tonic strength medium, free of calcium. Such a fibrin-based biomaterial develops a tight structure with thin fibers and small pore size suitable for use as an anti-adhesion barrier. In this invention, thrombin is no longer the variable which governs the tightness and the porosity of the fibrin material obtained, but still controls the clotting time. The mechanical behavior, high-water capacity, and releasable retention properties for therapeutic agents of this fibrin structure causes the fibrin material to be ideally suited for use as a drug delivery device, capable of delivering proteins, hormones, enzymes, antibiotics, antineoplastic agents and even cells for local and systemic treatment of human and non-human patients.