Leachable components in polymeric medical implants and disposables: a brief critical review

This paper presents a brief, critical analysis of the role of potential leachable ingredients in polymeric implants in relation to performance characteristics when in contact with the physiologic environment. Leaching is the reverse phenomenon of sorption, in which diffusing small molecules, such as additives, are removed by constant or non-constant rates from the bulk to the surface of polymeric materials from which they enter the physiologic milieu. Improved extraction procedures must be accompanied by thorough physico-chemical, mechanical, and biological testings aimed at the better simulation of the in vivo performance. There is a need to develop potentially non-leaching additives for polymers intended for biomedical uses.