Efeito da esterilização por radiação ionizante em cápsulas gelatinosas duras vazias

Abstract

Hard capsules are made from gelatine, a polymer of organic origin obtained through the hydrolysis of collagen present in animal tissues. Gelatin can be degraded by microorganisms. Gamma irradiation is considered an effective sterilization process, however its application can alter the chemical structure of the product. The present work aimed to evaluate the effect of ionizing radiation by gamma rays in hard gelatin capsules in doses equivalent to 05 kGy, 15 kGy and 25 kGy. The effect was evaluated using physicochemical parameters of the capsules as moisture content, mass, body length, cap length and disintegration time. The characterization of the chemical effects was done by scanning electron microscopy, infrared spectroscopy in the infrared region, X-ray diffractometry and thermal analysis using differential scanning calorimetry techniques and thermogravimetry. Inoculations were carried out with a population of Bacillus subtilis, a gram-positive spore-forming gram-positive microorganism, in a substrate obtained by diluting the capsules to evaluate the sterilizing effect of gamma-ray radiation. The results show that gamma radiation does not interfere with physical parameters of the capsules and surface morphology. Chemical changes were detected, indicating the formation of crosslinking as a consequence of the interaction between gamma radiation and gelatin molecules. The results obtained allow us to conclude that the radiation is effective in the reduction of the microbial population and can be used as a sterilization technique of hard gelatin capsules but, the stability of pharmaceutical preparations with irradiated capsules in their formulation should be evaluated.