Makale 2000-2009 yılları

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Browsing Makale 2000-2009 yılları by All Authors "Korkmaz, Mustafa"

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    Effects of radiation on carbapenems : ESR identification and dosimetric features of gamma irradiated solid meropenem trihydrate
    (Taylor and Francis Ltd., 2006) Tepe Çam, Semra; Polat, Mustafa; Korkmaz, Mustafa; TAEK-SANAEM
    In the present work, effects of gamma radiation on solid meropenem trihydrate (MPT), which is the active ingredient of carbapenem antibiotics, were investigated by electron spin resonance (ESR)spectroscopy.Irradiated MPT presents an ESR spectrum consisting of many resonance peaks.Heights measured with respect to the spectrum baseline of these resonance peaks were used to explore the evolutions of the radicalic species responsible for the experimental spectrum under different conditions. Variations of the denoted 11 peak heights with microwave power, sample temperature and applied radiation doses and decay of the involved radicalic species at room and at high temperatures were studied. On the basis of the results derived from these studies, a molecular model consisting of the presence of four different radicalic species was proposed, and spectroscopic parameters of these species were calculated through spectrum simulation calculations. The dosimetric potential of MPT was also explored and it was concluded that MPT presents the characteristics of normal and accidental dosimetric materials.
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    Radiation sensitivity and dosimetric features of sultamicillin tosylate : an electron spin resonance study
    (Taylor & Francis, 2009) Tepe Çam, Semra; Polat, Mustafa; Korkmaz, Mustafa; TAEK-SANAEM
    Particular interest now centers on the preparation of steril-unit dose preparations. When preparations are purified from microorganisms using classic sterilization techniques, serious degradations may occur especially in temperature sensitive drugs and drug active components. Sultamicillin is the tosylate salt of double ester of sulbactam plus ampicillin. Sultamicillin tosylate (SULT) has previously been shown to be clinically and bacteriologically effective in a variety of infections. The use of high-energy radiation such as gamma rays for the sterilization of pharmaceuticals offers considerable interest because of the clear advantages this process has, compared to other methods of sterilization. However, radiosensitivity of irradiated pharmaceutical is important in this respect. Thus, radiosensitivity of SULT and its potential use as a dosimetric material were investigated by Electron Spin Resonance (ESR) spectroscopy in the present work. Samples of SULT powder were irradiated at doses of 3, 6, 10 and 15 kGy and ESR spectra were recorded at room and at different temperatures. Variations of different spectroscopic parameters with irradiation dose, temperature, and storage time were evaluated using data derived from experimental ESR spectra which exhibited five different resonance peaks. Stabilities of the radiolytic intermediates at high temperatures were also investigated through annealing studies performed at 340, 345 and 350 K. Rapid decrease in the resonance peak heights above 325 K was considered as a manifestation of unstable character of the radiolytical intermediates at high temperature although they decayed relatively slowly at room temperature. Seven different mathematical functions have been tried to fit experimental dose-response data and a power function of the applied dose was found to describe best the dose-response data.