?-radiolytic degradation of rosuvastatin in the air-saturated aqueous solution

Widespread environmental occurrence and persistence of pharmaceuticals have attracted great concern due to their incomplete removal by conventional wastewater treatment technologies. The use of radiation technology has proven to be a good and successful alternative where highly reactive species lead to high degradation level of pharmaceuticals. Among the most commonly prescribed pharmaceuticals is rosuvastatin (ROSU), cholesterol -lowering agent, which has been detected as a contaminant in wastewater and natural waters. The aim of the present study was to investigate the gamma-radiolytic degradation of ROSU in aqueous solutions under different conditions. The focus was given to the most applicable conditions, the degradation of ROSU in air, where dominant reactions of center dot OH radicals with ROSU are expected. Therefore, the reaction rate constant of ROSU with center dot OH radicals (2.15 +/- 0.07 x 1010 M-1 s-1) was determined by laser flash photolysis. By combined gamma-radiolysis and mass spectrometry study, the reaction mechanism of radiation degradation of ROSU was proposed and the radiolytic products were identified.

Automated summary

The widespread occurrence and persistence of pharmaceuticals in the environment have raised concerns due to their incomplete removal by conventional wastewater treatment methods. Radiation technology has been proven to be an effective alternative, as highly reactive species lead to high levels of pharmaceutical degradation. This study focuses on the gamma-radiolytic degradation of rosuvastatin (ROSU) under different conditions, particularly in air where the dominant reaction is expected to be with center dot OH radicals. The reaction rate constant between ROSU and center dot OH radicals was determined to be 2.15 +/- 0.07 x 1010 M-1 s-1 using laser flash photolysis. The proposed reaction mechanism and identified radiolytic products of ROSU degradation were determined through combined gamma-radiolysis and mass spectrometry analysis.