The present paper discusses a comparative study concerning performance efficiency and sustainable impact of three purification processes for degenotoxification of Active Pharmaceutical Ingredients (APIs) post reaction streams: recrystalization., flash chromatography and organic solvent  nanofiltration (OSN).  Two case studies in each process were selected for evaluation of the separation technologies featuring the same model API being Mometasone furoate (Meta) glucocorticoid and two genotoxic impurities (GTIs).  Me mesylate (MeMS) and 4-dimethylaminopyridine (DMAP) were chosen as model impurities due to their incidental appearance in glucocorticoids based on a common methanesulfonylation manufactiring step.  Successful degenotoxification was achieved in all cases concerning DMAP and MeMS reaching final GTI levels below the regulatory thresholds with the exception of DMAP using recrystalization.