Gamma irradiation sterilizations

Finally, gamma irradiation sterilized products are safe products. Gamma radiation leaves no residues, and at doses used for sterilization it does not have sufficient energy to induce radioactivity in materials it traverses. Furthermore, gamma irradiation does not pose a radioactive waste problem. The radioactive material is completely contained, and when sources become too weak for industrial purposes there are contractual agreements to ensure their return to their source of supply, where they may either be disposed of or resold for installation in research irradiators. 

IV. INDUSTRIAL-SCALE COBALT-60 GAMMA IRRADIATION STERILIZATION... 

Pascaud RS, Evans WT, McCullagh PJJ, FitzPatrick DP. Influence of gamma-irradiation sterilization and temperature on the fracture toughness of ultra-high-molecular-weight polyethylene. Biomaterials 1997 May 18(10) 727-35. 

Sandoli RL, WC Ghiorse, EL Madsen (1996) Regulation of microbial phenanthrene mineralization in sediment samples by sorbent-sorbate contact time, inocula and gamma irradiation-induced sterilization artifacts. Environ Toxicol Chem 15 1901-1907. 

Polyethylene and polystyrene are examples of plastics subject to environmental stress cracking. Crack resistance tests have shown that surfactants, alcohols, organic acids, vegetable and mineral oils, and ethers provide an active environment for stress cracking of polyethylene. Table 6 lists typical sterile devices and plastic materials used to fabricate them, while Tables 7-9 list the potential effects of sterilization processes on polymeric materials. The effect of gamma irradiation on elastomeric closures has been studied by the Parenteral Drug Association [15]. 

As for the relative suitability of an electron beam (EB) facility vis-a-vis a cobalt-60 gamma facility, a key point is that although the ultimate chemistry is nearly identical in both cases, there is a notable difference in the penetration of the radiations. Another point is that the large capacity and consequent cost of EB machines require a relatively large production rate to justify their use. On the other hand, the EB machine, not being a radioactive source, is completely safe when switched off. Overall, since the sixties, sterilization by irradiation has steadily increased. However, most of this is by cobalt-60 gamma irradiation, the EB machines accounting for about a fifth or sixth of the total number of facilities. 

Gordon, B., Agalloco, J., et al. Sterilization of pharmaceuticals by gamma irradiation. J. Parenteral Sci Tech technical report 11.42 (suppl.) 1988. 

Figure 4.17 Growth of Lyophyllum tylicolor under certain defined conditions using humus. The humus was collected from a Pinus densiflora forest in the suburbs of Kyoto and brought to the laboratory at Kyoto University. As a pretreatment, the humus was dressed with 0, 5, 10, and 20 mg of urea per 1 gram of fresh material (from left to right) and incubated at 20°C. After 5 days, it was dried at 40°C, sterilized by gamma-irradiation, put in the plastic cup (23 mm in inner diam and 47 mm in depth), inoculated with hyphal suspension of this fungus, and incubated again at 20°C. Photograph was taken after further 10 days. (From Yamanaka, T., Ph.D. diss., Kyoto University, 2002. With permission.)...

TR 11 Sterilization of Parenterals by Gamma Irradiation, 1988 TR 13 Fundamentals of an Environmental Monitoring Program, 2001 TR 22 Process Simulation Testing for Aseptically Filled Products, 1996 TR 26 Sterilizing Filtration of Liquids, 1998... 

Memisoglu-Bilensoy, E.,and Hincal, A. A. (2006), Sterile injectable cyclodextrin nanoparticles Effects of gamma irradiation and autoclaving, Int. I. Pharm., 311,203-208. 

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