Irritation and Sensitization Potential of Approved Topical and Transdermal Delivery Systems: A Retrospective Study

This retrospective study analyzed the irritation and sensitization (I/S) potential of 30 generic topical and transdermal delivery systems (TDS) approved between 2012 and 2022. The study found that TDS products are generally well-designed, with limited instances of I/S failures. Four applications had at least one failed irritation study, primarily due to study design challenges, while only one application had a failed sensitization study. The failures did not correlate with specific inactive ingredients. The findings suggest that generic TDS products are typically effective in minimizing I/S reactions, though further research is needed to explore the impact of TDS design on I/S potential.