The Absorption of Cephalosporin on Vinyl Polymers to Form Antibacterial Surfaces

In order to obtain antimicrobial polymer compositions potentially suitable for catheter fabrication, a cephalosporin was bonded to ethylene-vinyl alcohol copolymers and to their derivatives containing hydrophilic positively or negatively charged groups. The polymers were characterized by chemical and physico-chemical techniques. The antibiotic was adsorbed at a density of 1.3 mg/cm ² onto the unaffected polymer surface. The density was increased up to 1.78 mg/cm ² when the polymer was derivatized. The elution rate of the antibiotic from the surfaces and its antimicrobial activity were determined. The underivatized polymer has shown antimicrobial activity for 24 h whereas the carboxylated polymer was active for 72 h. During this time 32% of the antibiotic was eluted from the underivatized polymer and approximately 15% from the derivatized polymer.