Drugs radio-sterilization

The major disadvantage of radio-sterilization is the peculiarity of the radiation chemistry induced simultaneously to sterilization, which requires a special study the irradiated drug is thus considered as a "new" drug. While micro organisms are killed, various products of degradation of the main compounds may appear in traces amounts though they are often the same as in thermal sterilization. 

The HPLC-UV-DAD was used for the analysis of final products results showed that many related compounds of cefotaxime were present prior to irradiation. Some of them had maxima around 320-380 nm and could be responsible for the change in color of the dissolved irradiated drug. The radiolytic products (25 kGy) were present in traces and were all below the qualification limit of0.1%.TheHPLC-UV-MS results showed that some radiolytic products detected were impurities already present in the non-irradiated cefotaxime and increased after irradiation. The other products were unique to radio-sterilization [14]. 

At the radio-sterilization doses, simulation predicts a greater loss than in the experimental results, possibly because some radiolytic products react with the water radiolysis radicals thus protecting the drug solute [16]. The simulations also predict similar solute concentrations without dose rate effects for E-beam or gamma irradiations whereas the opposite isfound in experimental results [17].The complexity ofthe radiolysis mechanisms at sterilization doses appears with the increase ofthe analytical efficiency. 

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