Considerations for the selection and/or development of generic inhalers
With the above FDA expectations in mind, other considerations for the selection and/or development of generic inhalers to minimize the need to conduct a CUHF study (or, if such a study is unavoidable, increase the likelihood of a successful CUHF study) include:
- Closely studying the RLD product’s labeling, physical product, and workflow, and determine which (sub)steps would constitute a critical task for a combination product.
- Considering which device from a variety of potential delivery devices will likely pose the slightest difference from a combination product critical task and/or interchangeable-use perspective by conducting one or more of the following activities:
- A Perception-Cognition-Action (PCA) task analysis –A task analysis that breaks down each step of use into three components: perception, cognition, and action. It will help the intended user understand what each task requires.
- A design critique/expert review –A methodological and independent review from one or preferably several human factors experts who use their knowledge and experience to interact with the device through the eyes of the intended user.
- A benchmark usability test of multiple potential delivery –A type of usability test devices to evaluate device use with RLD-experienced participants during which you document use errors and perform root cause analysis to determine if any potential delivery devices’ design features are at the root of the interaction issues RLD-experienced participants’ have.
- Developing labeling for the proposed generic inhaler that matches the RLD product’s labeling as closely as possible, only making text and/or graphical changes when essential to reflect key design differences.
- Conducting a pilot CUHF study per the proposed CUHF’s test method but with a smaller sample size in order to:
- Evaluate the CUHF’s test method to identify any issues that might hinder the conduct of a successful CUHF study.
- Confirm the likely sample size needed for a full CUHF study to achieve the necessary level of statistical power.
- Help determine whether there is a need to refine further the generic inhaler’s user interface from an interchangeable-use perspective.
Smoothing the way to an ANDA submission
The route to market for a generic inhaler can be smoother when developers take the applicable HF requirements and considerations for generic device development efforts into account before selecting a device to use for the combination product. The need to conduct a costly and time-consuming CUHF study can be avoided with careful design planning and execution.
Engaging one or more human factors professionals who will help conduct the necessary activities and provide expert advice along the way can help to avoid unforeseen challenges related to labeling, comparative task, and/or physical differences between a proposed generic and RLD that impact combination product critical task performance.
