CEFTAZIDIME KINETICS OF DIFFUSION IN INOCULATED AGAR PLATES

The ceftazidime concentration in agar plates inoculated with Pseudomon as aeruginosa was determined by high-performance liquid chromatography at fixed points (3, 6, 9, 12, and 15 mm) from the disk center and at fixed times (2, 4, 6, 16, and 24 h) to study the antibiotic kinetics o f diffusion. A statistical difference between the concentrations deter mined in the presence of microorganisms and in uninoculated plates aft er 16 and 24 h was evidenced and was probably ascribable to the drug h ydrolysis carried out by the induced beta-lactamase.