RADIOSTERILIZATION AND STEAM AUTOCLAVING STERILIZATION EFFECTS ON PHOSPHITE ANTIOXIDANT STABILITY

While the radiosterilization by gamma rays, is mainly employed for med ical devices, this procedure is not commonly used to sterilize and dec ontaminate raw material and finished product used in the pharmaceutica l industry. Depending on the countries, the requirements for obtaining approval to treat this class of product with gamma rays may be differ ent. Usually it is the responsibility of the manufacturer to demonstra te not only the integrity of the irradiated product, but also its effi ciency, safety and quality. Our work consists of a comparative study o f the effects of gamma radiotreatment at 25 kGy and steam sterilisatio n on phosphite antioxidant incorporated in polypropylene. The gamma ra diosensitivity compared with thermolability of this antioxidant was st udied by reversed phase HPLC, Fourier Transform Infrared (IRFT) and Di fferential Scanning Calorimetry (DSC). The results obtained proved tha t the phosphite incorporated into the polymer and treated with the two types of sterilisation is rapidly oxidized in phosphate. Nevertheless , this oxidation is more important when using radiotreatment at 25 kGy .