In silico Evaluation of Impurities Found in Some Generic Drugs of Piperacillin/Tazobactam

Characterization of impurities present in generic antimicrobial agents is not required according to the approval criteria for their sale worldwide. To assess the safety of generics, we conducted a structural estimation of impurities in six piperacillin/tazobactam generics and carried out an in silico analysis. Namely, these generics were compared with the brand name drug by HPLC and LC-MS. The mutagen that in silico analysis showed alert was detected in five of six generic products. It was estimated that this mutagen was an azido group of the precursor used in the synthesis process of tazobactam whose patent has expired. With regards to this mutagenic substance, pharmaceutical companies marketing a generic Piperacillin/Tazobactam product will have to check presence or absence of this mutagen before introducing the product to the market.