Electro-oxidation of cytostatic drugs: Experimental and theoretical identification of by-products and evaluation of ecotoxicological effects

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 334; pp. 1820 - 1827
• Main Authors: Barışçı, Sibel, Turkay, Ozge, Ulusoy, Ebru, Şeker, Mine Gül, Yüksel, Ebubekir, Dimoglo, Anatoli
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.02.2018
• Subjects: Capecitabine; Cytostatic; DFT modelling; Electro-oxidation; Methotrexate; Toxicity; Methotrexate; Capecitabine; Cytostatic; Toxicity; DFT modelling; Electro-oxidation
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2017.11.105

•The electro-oxidation of cytostatic drugs MTX and CPC has been studied.•The highest degradation efficiencies for both drugs was provided with CD of 30 mA cm−2.•The degradation rates were the most rapid in the neutral media for both compounds.•Metabolites of both drugs were detected by LC–MS-MS and DFT.•Ecotoxicity analysis showed that the metabolites of MTX should be of environmental concern. Methotrexate (MTX) and Capecitabine (CPC) as mostly used cytostatic drugs were degraded by electro-oxidation process in this study. Ti/IrO2-RuO2 electrode was used to provide anodic oxidation. The effect of change of current density, initial pH of the solution and supporting electrolyte concentration on electro-oxidation of cytostatic drugs was evaluated. Current density of 30 mA/cm2, neutral pH and supporting electrolyte concentration of 200 mg L−1 were determined as optimum operational parameters. After oxidation process, the transformation by-products of cytostatic drugs were identified by LC–MS-MS analysis. Density functional theory (DFT) modelling was performed and the calculations were given in harmony with analytic results. In addition, toxicity evaluation on the electro-oxidation was assessed due to the possible toxic effect of the metabolites after treatment process. Indeed, the transformation by-products of MTX showed toxic effects after treatment, however; the metabolites CPC did not cause toxicity although lower removal efficiency.