Design and labeling differences between generic and reference listed drug inhalers: human factors considerations in...

Area of Science:

• Pharmaceutical Sciences
• Medical Device Design
• Patient Adherence Research

Background:

• Generic inhalers are approved based on therapeutic equivalence to reference listed drugs (RLDs).
• However, subtle design and labeling differences between generic and RLD inhalers may affect usability and patient adherence.
• Limited comparative use data exists for these drug-device combination products, creating knowledge gaps regarding design variations and use errors.

Purpose of the Study:

• To systematically compare the physical characteristics, labeling, and instructional cues of reference listed drug (RLD) inhalers and their US FDA-approved generic counterparts.
• To identify specific design and labeling variations that could potentially lead to inhaler use errors.
• To understand the implications of these differences on product usability and patient adherence.

Main Methods:

• A systematic comparison of five RLD inhalers and eight US FDA-approved generic inhalers was conducted.
• A structured framework was employed to classify and analyze physical attributes, labeling elements, and instructional content.
• Data was sourced from publicly available materials, including the US FDA Orange Book.

Main Results:

• Significant differences were observed across all compared inhaler groups.
• Variations included device shape, mouthpiece design, dose counter placement, handling techniques, and instructional clarity.
• Group 1 exhibited the most pronounced differences, potentially leading to incorrect device handling, reduced drug deposition, and challenges in learning proper technique.

Conclusions:

• Design and labeling discrepancies between generic and RLD inhalers can introduce usability challenges, impacting correct usage and patient adherence.
• These differences may lead to cognitive and physical use errors.
• Future research should integrate user testing, digital human modeling, and diverse patient populations to further assess the impact of these variations.