Radiosensitivity and Dosimetric Features of Sultamicillin Tosylate: An ESR Study

Abstract. 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 1, 3, 6, 10 and 15 kGy and ESR spectra were recorded at room temperatures. Variations of different spectroscopic parameters with irradiation dose and storage time were evaluated using data derived from experimental ESR spectra which exhibited five different resonance peaks. The resonance peak heights decayed slowely 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.