Chemical Characterization

Chemical characterization shall precede any biological testing in the workflow used to establish the biological safety of medical devices, as required by ISO 10993. The chemical characterization helps replace certain biological tests and identify the additional tests if needed, to address the biological safety. Hence chemical characterization has been given greater importance.

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Extractable and Leachable (E&L) testing is performed to identify and quantify the chemical compounds in the medical device that could release from the medical device and raise potential toxicity concerns. The types of analysis carried out are exhaustive extractions (assessed by gravimetric analysis), simulated-use extractions, accelerated aging studies, and leachable studies. Extraction solutions are typically evaluated depending on the solvent utilized by LC-MS, GC-MS and ICP-MS. The list of compounds detected in the Extractable and Leachable (E&L) and their concentrations are reported.

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The information on the material of construction of the medical device or medical devices, including polymers, metals, ceramics, composites and chemicals associated with device production such as plasticizers, fillers, additives, cleaning agents and release agents plays a vital role in proper designing of E&L tests. The raw material data provided by the supplier can help build a picture of chemical composition. The device class, clinical intended use and contact times shall be considered in carefully designing the Extractable and Leachable (E&L) test.