Miyazaki, T.
Kaneko, T.
Yoshimura, T.
Crucq, AS.
Tilquin, Bernard
[UCL]
Fundamental information on radiosterilization of ceftazidime was obtained by electron spin resonance (ESR) measurement of free radicals produced in gamma-ray-irradiated ceftazidime at 4.2-295 K. Three types of free radicals are produced by gamma-irradiation. The first one shows septet lines in an ESR spectrum and decays at 230 K: it is assigned as a .C(CH3)(2)COOH radical. The second one shows triplet lines and decays at 293 K: it is assigned as iminoxyl radicals (>C=N-O.). The third one shows a broad singlet line and survives even at 295 K. The plausible assignment of this spectrum is discussed. It is concluded that an O-C bond of the gamma-irradiated ceftazidime is ruptured, producing the iminoxyl radicals and .C(CH3)(2)COOH radicals. The yields of free radicals increase linearly with the increasing dose of gamma-irradiation up to 10 kGy at 295 K as well as 77 K. Half of the radicals that show a broad singlet line survive at 295 K upon storage of the irradiated ceftazidime for 159 days. It is concluded that the ESR measurement of free radicals gives a good method for discrimination of irradiated antibiotics from non-irradiated ones and an estimation of an irradiation dose.
Référence bibliographique |
Miyazaki, T. ; Kaneko, T. ; Yoshimura, T. ; Crucq, AS. ; Tilquin, Bernard. Electron-spin-resonance Study of Radiosterilization of Antibiotics - Ceftazidime. In: Journal of Pharmaceutical Sciences, Vol. 83, no. 1, p. 68-71 (1994) |
Permalien |
http://hdl.handle.net/2078.1/49190 |