October 18-21, 2015
Single-use films in biopharmaceutical and biotechnology industries are mainly made from polymers such as PE, EVA and EVOH. Depending upon the environmental aggressiveness during various stages of the polymer lifetime, additives are added to protect them such as substituted hindered phenols acting as antioxidants, melt (processing) stabilizers, and to some extent as photo-antioxidants.
Ionizing radiation effects on polymers have been widely investigated. They consist mainly of free radicals production. These free radicals can in turn lead to degradation and or crosslinking phenomena (release of gases, discoloration, changes in mechanical properties and gas permeability, degradation and leaching of polymer additives into solvents, etc.) whose extent depends on many factors. In contrast, there is little information on the effect of ionizing radiation on the additive package properties used in multilayer packaging films. A specific influence on chemical transformations of phenols is induced as well.
Strong discoloration of the polymer stabilized with phenolic antioxidants originates for instance mainly from the reaction products of the stabilizers. The color development can be attributed to the formation of conjugated diene compounds, arising as a consequence of trapping of radicals by phenolics. The discoloration depends on the structure and concentration of the phenolic transformation products.
As a result of the described complexity, a huge variety of potential extractable compounds can be expected from antioxidants. This work focuses of highlighting the degradation products we may expect from the thermal and radiative degradation of the primary and secondary anti-oxidants and to address complexity of identifying properly the by-products one may detect in extractable study applied to pharmaceutical single use products.
Samuel Dorey, Fanny Gaston, Nathalie Dupuy, Sylvain Marque, and Gerard Audran, "Identification of antioxidant by-products based on their specific chemistry and their potential detection during SUS extractable study" in "Single-Use Technologies: Bridging Polymer Science to Biotechnology Applications", Ekta Mahajan, Genentech, Inc., USA Gary Lye, University College London, UK Eds, ECI Symposium Series, (2015). http://dc.engconfintl.org/biopoly/41