Evaluation of the Photostability of Ivermectin

Ivermectin (IVM) is a pharmaceutical antiparasitic agent with a broad range of medicinal properties that are comparable in impact to those of penicillin and aspirin. The molecule’s structural composition includes functional groups that indicate the potential for photoreactivity. However, there is a paucity of information regarding its photostability, particularly in tropical regions where parasitic diseases and intense solar radiation intersect. It would be beneficial to investigate the chemical transformation of this compound in a variety of natural aqueous environments under different irradiation sources. This knowledge gap motivated this study. Therefore, the chemical alterations of IVM were investigated in various natural aqueous media when exposed to solar radiation (UVA-Vis). In particular, an evaluation of its photostability was conducted at wavelengths of 350 and 254.5 nm. It is noteworthy that photodegradation occurred primarily at 350 nm. Additionally, IVM demonstrated photohemolytic effects on human erythrocytes, indicating phototoxicity. This suggests the presence of photoinduced mechanisms by this drug for the generation of free radicals, including singlet oxygen (¹O₂, type II mechanism), superoxide anion, and hydroxyl radical (^.O₂ and ^.OH, type I mechanism). The latter would also entail the interaction of the IVM molecule with the membrane of human red blood cells, which would signify a considerable biological impact. Furthermore, through computational calculations, potential photoproducts formed during IVM irradiation were deduced, simulating experimental conditions. Our findings contribute to an enhanced comprehension of IVM’s behavior under solar exposure, particularly in tropical contexts. Additional research is imperative to address its emerging biological activity status and potential implications for biomedical applications.