Seeking a common human factors language for the development and testing of injection devices

Injection devices include drug-device combination products incorporating a needle for subcutaneous medication delivery. Often utilized by patients and caregivers, it is important for injection device user interface (UI) design to be intuitive to use outside of a traditional healthcare setting. To ensure safety and efficacy, the FDA requires a human factors (HFs) assessment as part of a new drug application (NDA) for new drug products and through the abbreviated new drug application (ANDA) pathway for generic drug approval. Despite the importance of defining injection device features as part of the HFs assessment, no comprehensive list of related definitions has previously been established. This paper compiles such definitions creating a common language for use in HFs assessments. Specifically, injection device classifications and characteristics are defined and then related to UI features and common tasks required for successful devices use. Information presented can be applied during device development and testing creating a common language for engineers, designers, and regulators. The definitions may be especially impactful for the approval of generic injection devices as the ANDA pathway for generic drugs requires a UI comparison of the proposed generic device to that of the existing reference listed drug.