title: EPR studies of free radicals decay and survival in gamma irradiated aminoglycoside antibiotics: sisomicin, tobramycin and paromomycin.
abstract: Radiation sterilization technology is more actively used now that any time because of its many advantages. Gamma radiation has high penetrating power, relatively low chemical reactivity and causes small temperature rise. But on the other hand radiosterilization can lead to radiolytic products appearing, in example free radicals. Free radicals in radiative sterilized sisomicin, tobramycin and paromomycin were studied by electron paramagnetic resonance (EPR) spectroscopy. Dose of gamma irradiation of 25kGy was used. Concentrations and properties of free radicals in irradiated antibiotics were studied. EPR spectra were recorded for samples stored in air and argon. For gamma irradiated antibiotics strong EPR lines were recorded. One- and two-exponential functions were fitted to experimental points during testing and researching of time influence of the antibiotics storage to studied parameters of EPR lines. Our study of free radicals in radiosterilized antibiotics indicates the need for characterization of medicinal substances prior to sterilization process using EPR values. We propose the concentration of free radicals and other spectroscopic parameters as useful factors to select the optimal type of sterilization for the individual drug. The important parameters are i.a. the τ time constants and K constants of exponential functions. Time constants τ give us information about the speed of free radicals concentration decrease in radiated medicinal substances. The constant K(0) shows the free radicals concentration in irradiated medicament after long time of storage.
authors: Department of Biophysics, School of Pharmacy, Medical University of Silesia, Jedności 8, 41-200 Sosnowiec, Poland. swilczynski@sum.edu.pl
authors: Sławomir
authors: S
authors: Wilczyński
authors: Barbara
authors: B
authors: Pilawa
authors: Robert
authors: R
authors: Koprowski
authors: Zygmunt
authors: Z
authors: Wróbel
authors: Marta
authors: M
authors: Ptaszkiewicz
authors: Jan
authors: J
authors: Swakoń
authors: Paweł
authors: P
authors: Olko
mesh_terms: D000465:Algorithms; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000528:radiation effects*; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000032:analysis*; D005720:Gamma Rays; D006801:Humans; D007700:Kinetics; D008543:Melanins / Q000378:metabolism; D010303:Paromomycin / Q000737:chemistry / Q000528:radiation effects*; D012853:Sisomicin / Q000737:chemistry / Q000528:radiation effects*; D013242:Sterilization / Q000379:methods*; D014031:Tobramycin / Q000737:chemistry / Q000528:radiation effects*
chemical_list: D000900:Anti-Bacterial Agents; D005609:Free Radicals; D008543:Melanins; D010303:Paromomycin; D014031:Tobramycin; D012853:Sisomicin