Autori: G. Damian, G. Schmutzer, D. Petrisor
Editorial: INOE&INFM, Journal of Optoelectronics and Advanced Materials, 9(3), p.680-683, 2007.
Electron Paramagnetic Resonance (EPR) spectroscopy was used to study the behavior of the light-induced free radicals in the nifedipine [C17H18N2O6, 3,5-pyridine dicarboxylic acid, 1,4-dihydro-2,6-dimethyl-4-(2-nitro-phenyl)- dimethyl ester], and
to characterize the specific features of these radicals. Powder samples of nifedipine were investigated for a comparison between radiation damage in drug and in active substance. The nifedipine has not EPR signal before illumination or before UV irradiation, but the relative yielding of free radicals, appeared after irradiation, depends on the exposed time. By computer simulation of experimental spectra, some spectroscopic properties and suggestions concerning possible structure of the free radicals are discussed in this paper. Two radical species was found in pharmaceutical formulation tablets corresponding to active substance and ingredients.
Cuvinte cheie: EPR spectroscopy, Free radicals, Nifedipine