Radiation Sterilization for Medical Devices

This Summer I interned at Johnson & Johnson (where I still work)  and had the pleasure of going on several trips to facilities. The trip that stands out most to me was the sterilization facility where looking back on it now, is the most standard-dense place I have ever been to.  Validation of sterilized materials is outlined by ISO 11137 and has a strict set of practices that are mandated by the FDA.  Gamma and Electron Beam (E-Beam) sterilization methods are effective at removing undesired life from sterilized materials, however there is the risk that the radiation may break down the material themselves, resulting in the need for careful calibration and testing.  Material density is also a factor as some spots on the material may not receive the same level of radiation as others, reducing the effectiveness.  The engineers have a set dose of radiation for each particular item that they sterilize as it is a goal to use as little radiation as is safe despite low if non-existent residual rates.  One engineer told us that a day of working with the E-Beam machine would leave on him (all engineers constantly monitor their radiation exposure as defined in the standard) about the same radiation as eating a banana. The main reason for monitoring this is that if something were to go wrong , they would be able to tell how much radiation an individual was exposed to in order to save them. Most of the medical devices we saw were inside of individual vacuum sealed bags that go into the radiation machine with the device inside of them.  These bags are also tested to make sure that the seal is not worn out by the radiation.  Shipment to and from the facilities is also standardized as the sterilized devices are placed in containers based upon how invasive the device is. 

Most of these devices are meant for single use only, however; it is clear that many of these devices structurally can stand re-sterilization and reuse.  This reduces the cost of these devices to a fraction of their original cost, but this practice of reprocessing is controversial among those who have distrust in the validation procedures and motives of the production companies. Reprocessing of medical devices is a rather recent procedure that began with Category III (non-invasive) devices due to this skepticism.  Manufactures are not happy with this and aim to structure their contracts in such a way that marginalize the advantage of reprocessing single-use devices.  Medical costs are simply too much for many families to handle and techniques like this will help greatly.  The FDA has allowed for certain devices to be reprocessed but legislation is needed to further the program to more devices.  The best interest of the general public should outweigh the financial gain of the manufacturers. 



 Resources :
http://www.lso-inc.com/sterilization-validation-services/iso11137-gamma-ebeam-sterilization.html

http://medicaldesign.com/contract-manufacturing/electron-beam-sterilization-more-versatile-you-think

http://www.ucdmc.ucdavis.edu/sustainability/reprocessing.html