Medical devices can be damaged by the presence of oxygen or moisture during sterilization and during the shelf life of the product. To remove oxygen and moisture, medical device producers use a few in line procedures in combination with a desiccant within packages are vacuum packaging and nitrogen or argon purging and flushing. These procedures are costly and inefficient and do not completely ensure the complete removal of oxygen. 'Active' packaging does more than simply provide a barrier to outside influences. It can control, and even react to, events taking place inside the package. Active packaging systems are increasingly used in medical devices, pharmaceuticals, and foods. Such systems scavenge oxygen gas within the package and improve product shelf life and safety. Oxygen absorbers from active packaging systems provide an efficient alternative to vacuuming and gas-flushing technologies. Two scavenging films of particular interest are called CSP-1940 and CSP-1941 from CSP Technologies, USA. CSP-1940 scavenging film removes O2 and moisture, whereas CSP-1941 absorbs only O2. The mode of activation for O2 scavenging for both CSP scavenging films is UV radiation, and the activation equipment and process are easy to implement and validate. These films have been incorporated into new drug applications in both USA and the European Union. CSP’s core technology focuses on a patented three-phase polymeric system that generates a micro architecture of one polymer within another. By combining two immiscible polymers with a particulate, CSP creates a network of interconnected channels that facilitate the controlled transport of small molecules throughout the blend. Uniformly dispersed, the pathways allow the diffusion of volatile substances into, out of, or through the material, enabling it to be custom formulated to absorb moisture, gases, odors, and aldehydes; release nutrients, biocides, flavors, or fragrances; or modify the transport properties of particular plastics. Many commercially available products today use this three-phase polymeric system in protecting and enhancing the products’ useful life. The CSP scavenging films’ polymer system is a blend of components. The first is an oxidizable base polymer, poly (ethylene methylacrylate cyclohexenyl methylacrylate) (EMCM) The second component is a masterbatch consisting of a transition metal catalyst and a non migratory photo initiator, in addition to a channeling agent and a base polymer. The non migratory photo initiator allows the packager to initiate the O2 scavenging mechanism just prior to filling, which maximizes the capacity of the active scavenging component. Upon UV-radiation activation, the polymer system of the CSP scavenging films absorbs residual O2 (via irreversible bonding) in the package headspace and additional O2 that may permeate through the primary packaging barrier. UV radiation initially excites the photo initiator. A transitional metal catalyst helps initiate a chain reaction with EMCM, in turn making it more reactive with Oxygen. The CSP scavenging films transition to the color brown over time as EMCM reacts with Oxygen. This change of color provides a visual cue that the CSP scavenging films are functioning properly. More importantly, EMCM is unique in that no degradation products are generated as a result of the Oxygen scavenging process. (Source: mddionline.com)