Radiation Processing of Polymers for Medical and Pharmaceutical Applications Darmawan Darwis,* Erizal, B. Abbas, Farah Nurlidar, D. Pribadi Putra Summary: The use of ionizing radiation for the preparation of polymeric biomaterials is one of the examples of the application of atomic energy for the benefit of humanity. Radiation processing is based on the use of high energy ionizing radiation to induce chemical and biological changes in irradiated systems. High energy electron (EB) under 10 keV and gamma irradiation are the most frequently used of ionizing radiation for synthesis, modification of polymers, and sterilization of medical devices. Potential biomedical and pharmaceutical applications of these polymers are implants, topical dressings, injectable formulations, drug delivery devices, diagnostic assays, and immobilized enzyme. Through radiation crosslinking or degradation processes, polymers with specific characteristics can be prepared. The advantages of radiation processing include the absent of any chemical residues (since no chemical additives are requires to initiate the reactions), can be used at all temperatures, can be limited to the surface only and in certain cases, the synthesis/modification of materials can be combined with sterilization. Keywords: biomaterial; crosslinking; degradation; electron beam; gamma irradiation; polymer; radiation processing; sterilizationbiomaterial Introduction Radiation processing can be defined as exposure of materials with high energy radiation (ionizing radiation) to change their physical, chemical or biological char- acteristics, to increase their usefulness and safe, or to reduce their impact on the environment. [1–3] High energy electron (electron beam), gamma rays emitted by radioactive nuclides, and X-rays (brems- strahlung) emitted by energetic electrons are the most frequently used of ionizing radiation in industry. The principal indus- trial applications of ionizing radiation are sterilization of health care products includ- ing pharmaceuticals, irradiation of food and agriculture products (for various end objectives, such as disinfestation, shelf life extension, sprout inhibition, pest control and sterilization), and materials modifica- tion (such as polymerization, polymer crosslinking, grafting, and degradation, and gemstone colorization). [4–5] The advantage of radiation process compare to traditional process is the absent of any chemical residues (since no chemical additives are requires to initiate the reactions). It can be used at all temperature and can be limited to the surface only. In certain cases the synthesis/modification of materials can be combined with sterilization. For sterilization purposes, process val- idation plays a very important role in quality assurance and quality control as emphasized by various documents of the International Organization for Standard- ization (ISO); in ISO 11137.1. For example, process validation is understood as a Center for Application of Isotopes and Radiation Technology, National Nuclear Energy Agency, Jl. Lebak Bulus Raya No. 49, Jakarta 12070, Indonesia Fax: (þ62) 21 7691607; E-mail: darmawan_p3tir@batan.go.id Macromol. Symp. 2015, 353, 15–23 DOI: 10.1002/masy.201550302 | 15 © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim wileyonlinelibrary.com