title: Free radical formation in chloramphenicol heated at different temperatures and the best thermal sterilization conditions - application of EPR spectroscopy and UV spectrophotometry.
abstract: Free radicals in thermally treated chloramphenicol were examined by electron paramagnetic resonance (EPR) spectroscopy. The parameters and shape of EPR spectra were analysed and free radical concentrations were obtained in the tested drug samples. Chloramphenicol was thermally sterilized at pharmacopeia conditions: 100 °C (120 min). Sterilization was also carried out at different conditions, 110 °C (60 min) and 120 °C (30 min), for comparison with pharmacopeia settings. Microbiological analysis was performed on the samples to confirm sterility. The aim of this work was to determine the concentration of free radicals in chloramphenicol following thermal sterilization at pharmacopeia conditions and compare this with other sets of conditions [110 °C (60 min) and 120 °C (30 min)]. The best conditions of thermal sterilization are determined as those that kill microorganisms and produce the lowest amounts of free radicals in this drug. It was concluded that the optimal temperatures and times for the thermal sterilization of chloramphenicol are 100 °C and 120 min and 110 °C and 60 min. A temperature of 120 °C coupled with a heating time of 30 min was rejected for thermal sterilization because of the high amount of free radicals produced by the drug samples.
authors.affiliation: a Department of Biophysics , School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia in Katowice , Sosnowiec , Poland.
authors.forename: Paweł
authors.initials: P
authors.lastname: Ramos
authors.affiliation: a Department of Biophysics , School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia in Katowice , Sosnowiec , Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Pilawa
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000378:metabolism; D002701:Chloramphenicol / Q000737:chemistry* / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D005609:Free Radicals / Q000737:chemistry* / Q000378:metabolism; D006358:Hot Temperature; D008872:Microwaves; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013242:Sterilization / Q000379:methods*
chemical_list: D000900:Anti-Bacterial Agents; D005609:Free Radicals; D002701:Chloramphenicol
keywords: Chloramphenicol; EPR spectra; EPR spectroscopy; free radicals; thermal sterilization