Influence of radiation sterilization on the stability of trifluorothymidine

The influence of radiation sterilization on the stability of trifluorothymi dine (TFT) was investigated. TFT was irradiated under ambient atmosphere wi th a Co-60-source and with an electron accelerator at 25, 50, and 100 kGy, respectively. The radiation-induced effects were determined by chromatograp hic and spectroscopic methods as well as potentiometrically with a fluoride selective electrode. TFT was moderately stable to ionizing radiation. The degradation induced by electron-beam irradiation was significantly (P = 95% ) smaller than by gamma -irradiation. The radiolysis products amounted to a bout 0.25% after electron-beam irradiation at 25 kGy, and to about 0.50% af ter gamma -irradiation, respectively. The main irradiation product was 5-tr ifluoromethyluracil (TFMU). In addition five further impurities were detect ed with HPLC. Identification of degradation products was performed using HP LC-ESI-MS. A degradation path of TFT after radiation sterilization was show n. (C) 2001 Elsevier Science B.V. All rights reserved.