Attack of cefotaxime by different radicals: comparison of the effects.

Free radicals are physiological products and can react to administrated drugs. Metabolic transformations by radical mechanisms are, therefore, possible. A fundamental study of radio-induced degradation of aqueous solutions of sodium cefotaxime, a third generation cephalosporin, was realized to describe these possible radical mechanisms. Different radicals produced by the radiolysis method (.OH, N3., Br2.-, Tbut., eaq- + .OH, and exq- + Tbut.) were successively used to induce the radical mechanisms and their effects were compared. All these radicals induce the formation of a same main radiolysis product identified as anticefotaxime. Radical mechanisms induced by N3., Tbut., and eaq- include chain reactions to explain the formation of anticefotaxime contrary to those induced by .OH and Br2.-.