The adsorption of Doripenem (beta-lactam antibiotic belonging to the subgroup carbapenem) from aqueous solution using bentonite as the adsorbent was studied at various pH of the solution. The doripenem loaded in bentonite which called doripenem-bentonite composite was subsequently used as the antibacterial agent. The effect of pH on the adsorption of doripenem onto bentonite was studied at pH 2 to 10 at an initial concentration of 200 mg/L and temperature of 30oC. The kinetics of adsorption was also studied, and the results were adjusted by pseudo-first-order and pseudo-second-order models, and the result indicates that pseudo-first-order gave better performance in representing the kinetics data of adsorption of doripenem onto bentonite. The adsorption isotherm of doripenem onto bentonite could be described well by the Langmuir model. Buffer solution at pH 3 gave better release of doripenem from the surface of bentonite. The microbiological testing results indicate that doripenem-bentonite composite has potential application to inhibit the growth of Staphylococcus aureus and other bacteria
