Analysis of Elastomers for Medical Applications

Elastomers are used widely in the medical, pharmaceutical and healthcare industries.  Material advances over the years have resulted in “cleaner” elastomers for such applications, transitioning from e.g. the use of standard diene-type  rubbers (e.g. EPDM and Nitrile) which contain relatively high levels of reaction products/breakdown products and potentially harmful compounds, such as nitrosamines, to e.g. butyl, chlorobutyl and bromobutyl rubbers which have low extractables due to improved manufacturing processes using low levels of additives and high curing efficiency.  These changes have been driven by regulatory requirements for the use of materials which will not harm the end user / patient and which are compatible with the biological environment in which a medical device may be used.  Extractables and leachables continue to be an area under ever increasing scrutiny by the organizations such as the Food and Drugs Administration (FDA) and the European Medicines Agency (EMEA).  Medical device, pharmaceutical and healthcare companies must demonstrate that the patient is not exposed to harmful species from the container closure system.  This includes interaction from not only the container closure system but also secondary packaging, the storage environment and processing equipment

A variety of analytical techniques are used to generate a suitable regulatory data package.  Gas chromatography and liquid chromatography along with mass spectrometry are key techniques, particularly those such as GCxGC-TOFMS which offer an enhanced level of separation and, hence, identification capability  Samples preparation and route of analysis will depend on the application in question.  Key information is gathered up front to determine suitable extraction media and extraction technique.  For elastomers / rubbers, the case for special case compounds (e.g. nitrosamines) must also be considered and accounted for.  Extracts are then analyzed and all data compared to commercial spectral libraries and proprietary internal company libraries to enable identification of compounds and thus generate an extractables profile for the product. Data evaluation will determine if there are any potentially harmful compounds which will require further assessment for leachables, and /or toxicological assessments.

All testing is performed in accordance with PQRI recommendations and analytical limits for extractables and leachables testing. As low as reasonably practical (ALARP) levels must additionally be considered for special case species, such as MBT and nitrosamines.