Elast-Eon polymers are a class of materials suitable for use in long-term implantable medical devices. They are the copolymers of methylene diphenyl diisocyanate (MDI) based polyurethanes and hydroxyl-terminated polydimethyl siloxane, and as a result combine the biostability and biocompatibility of silicones with the mechanical properties of polyurethanes. In order to ensure product safety and meet regulatory requirements, it is important to confirm the absence or presence of toxic 4,4′-methylene dianiline (MDA) in aqueous extracts of Elast-Eon. The present work focusses on the development of an analytical technique to detect any leachable MDA from Elast-Eon polymers. No traces of MDA could be detected in the aqueous extracts from Elast-Eon, or from sterilized and aged (accelerated oxidized) samples of Elast-Eon.