The Effect of Gamma Radiation on Cephalosporin and Amino glycosides Antibiotics

Abstract

The microbial contamination of pharmaceutical preparations is considered to be a common problem which has been reported for several medicaments. Thus, many of the ingredients used in pharmaceutical formulations can become substrates for microorganisms when the right conditions are present. In this regard, one hundred antibiotic samples were collected from the Egyptian pharmacies. These samples were tested for their microbial load. Then, the isolated organisms were identified. After that, the active ingredients of the drugs were irradiated in order to determine the sterilization dose. The efficiency of the sterilization was tested using organoleptic properties (e.g., color, solubility, pH measurement, HPLC (High Performance Liquid Chromatography)), which were used in order to determine the effect of sterilization on the drug structure and the microbial load. The results revealed that the fungal isolates were more predominant than bacteria, with the percentage of 88.3% and 11.7% respectively. The dose response curve for the two fungal isolates MAM-F15 and MAM-F48 showed that 6.0 kGy and 5.0 kGy reduced the viable count of the two fungal isolates completely. Thus, the dose of 5.0 kGy reduced the viable count of MAM-F15 by 4.48log cycles, while 4.0 kGy reduced the viable count of MAM-F48 by 3.58 log cycles. The doses, tested for the sterilization of active ingredients of Amikacin, Ceftazidime and Cefotaxime, were 3.0, 5.0, 7.0, 10.0 and 25.0 kGy. The dose of 3.0kGy was sufficient to reduce the microbial load. On the other hand, the higher gamma radiation doses could not degrade the chemical structure of the active ingredients as determined by HPLC, indicating the stability of the drugs for sterilization by the gamma radiation