Penicillinase is the enzyme that inactivates the antibiotic, hydrolyzing β-lactam nucleus and leading to inactivation of biological product. In this study, we obtained a combined kinetics: chemical and enzymatic degradation of the penicillin in enzymatic aqueous medium. Thus, we have obtained kinetic parameters of β-lactamase action with attenuated activity on penicillin G, by the separation of the two effects.