Corticoids Photodegradation in Homogenous and Micro-heterogeneous Media. Cytotoxicity of Photoproducts

R. DANIEL CACCIARI; MARIANELA S. VILLAVERDEA; FLORENCIA MENIS; EUGENIA REYNOSO; CAROLA SABINI; HERNÁN A. MONTEJANO; MARÍA A. BIASUTTI

Villa Carlos Paz

Encuentro; XIII ELAFOT; 2017

The use of biologically active substances with anti-inflammatory properties such as corticosteroids has increased considerably in the last decades. Particularly, the compounds of our interest: Prednisolone (Predn), Prednisone (Pred) and Dexamethasone (Dx) belong to the family of glucocorticoids (GC) most commonly used.Two aspects related to the interaction of the pharmaceuticals with light are of great interest. On the one hand the photostability of these compounds during their production and storage, and on the other hand their photodecomposition in less aggressive species to the environment when the drugs are removed, metabolized or not, throughout effluents. These GC absorb UV-B radiation and may participate in photochemical processes, which can result in their own decomposition by unimolecular photodegradation or by the attack of reactive oxygen species (ROS) generated from the interaction of the GCs excited states with oxygen. In these sense, kinetic and mechanistic aspects of the direct photodegradation of GCs have been studied in aqueous and micro-heterogeneous medium under different atmospheric conditions by stationary and time-resolved techniques. Also, the cytotoxicity of the GCs and the photoproducts generated in different atmospheres were evaluated on model cell lines.