Understanding Relative Response Factors: How HPLC-CAD Helped Resolve a Misleading Impurity Concern

Lior Stern, Analytical R&D, TAPI, Netanya, Israel (lior.stern@tapi.com)

The use of HPLC with a Corona aerosol detector (CAD) enabled a clearer understanding of impurity assessment during process scale up development. CAD-based quantification and correlation with UV data demonstrated that a newly observed unknown impurity, despite its high relative response, posed no real quality or safety risk. This rapid and efficient approach allowed mitigation of an unnecessary impurity-related risk without full impurity identification, highlighting the value of CAD in fast, data-driven decision-making tool.