FDA Draft Guidance on Technical Considerations for Demonstrating The Reliability of Emergency-Use Injectors has been Published
This FDA emergency injector guidance published in April 2020, indicates how to select a marketing application route and how to make that application.
Because emergency injectors are used in uncontrolled situations by inexperienced (or even untrained) people reliability and ease of use has to be built into every stage of their design, manufacture and lifetime. Human factors studies play a significant role in ensuring that a functioning auto-injector will be used correctly at the time of a ‘single opportunity’. Because the nature of the device is single use, pen injector validation testing and process validation play a large role in ensuring that the pen is functioning correctly at the time of necessity. The FDA suggests that a maximum of 1 failure in 100,000 injection attempts is an acceptable level of risk.
Medical Engineering Technologies’ laboratories provide a full range of stability and performance testing. The Guidance states that any test failures should be investigated using a Fault Tree Analysis. Our experienced scientists can also assist in this process.
Testing should be carried out on final, packaged product at interim time points throughout its lifetime (accelerated ageing initially) to assess if there are any trends in performance. Other considerations in testing include resistance to transit and distribution simulation and whilst in the end user’s possession. The challenges should include storage conditions, orientation, vibration, shock, airborne dust, temperature, and pressure. Test methods particularly accelerated ageing should be validated. Sample sizes need a statistical rationale.
Needle performance is of particular interest during design validation. Features noted include resistance to bending and fracture, patency, and absence of particles. Key to successful performance is injection depth in different tissue types and through a variety of clothing options. Additional areas of concern are: does the needle reach its intended depth and then start the drug delivery? Also does it stay there until the dose is complete?
The human factors testing should include not only ease of use but also extraction from packaging, removal of any needle covers and the absence of any misleading indicators of a successful dose. All of this should be performed in a variety of environments to simulate actual use in controlled and chaotic situations.
This approach is targeted at ensuring that in the event of an emergency the correct dose will reliably delivered to the right place with no misunderstandings.
Contact MET for validation, batch release and periodic testing.