title: Attempts at correlation of the radiolytic species of irradiated solid-state captopril studied by multi-frequency EPR and HPLC.
abstract: The purpose of this study was to provide insight into the processes that occur after the irradiation of solid-state drugs. Electron paramagnetic resonance (EPR) experiments were performed at two different frequencies, X-band (about 9.5 GHz) and Q-band (about 34 GHz), to identify the radicals present in irradiated captopril. The results confirmed that an irradiated drug can trap several main radicals. Moreover, the radical composition varied as a function of the treatment. In addition, non-volatile final products were studied by liquid chromatography coupled to UV and to mass spectrometry (LC-MS). The variation of the radical composition did not influence the profile of the final products; this appears to indicate that, in the case of captopril, the trapped radicals observed by EPR are not the main precursors of the final products. Finally, high-performance liquid chromatography data appear to indicate that radiosterilization of captopril is feasible.
authors.affiliation: Laboratory of Chemical and Physicochemical Analysis of Drugs, UCL, B.1200 Brussels, Belgium. alix.engalytcheff@cham.ucl.ac.be
authors.forename: Alix
authors.initials: A
authors.lastname: Engalytcheff
authors.forename: René
authors.initials: R
authors.lastname: Debuyst
authors.forename: Gauthier C A M
authors.initials: GC
authors.lastname: Vanhaelewyn
authors.forename: Freddy J
authors.initials: FJ
authors.lastname: Callens
authors.forename: Bernard
authors.initials: B
authors.lastname: Tilquin
mesh_terms: D002216:Captopril / Q000737:chemistry / Q000528:radiation effects*; D002851:Chromatography, High Pressure Liquid; D004578:Electron Spin Resonance Spectroscopy; D013058:Mass Spectrometry; D014961:X-Ray Diffraction
chemical_list: D002216:Captopril