Quality by Design: Multidimensional exploration of the design space in high performance liquid chromatography method development for better robustness before validation

Robust HPLC separations lead to fewer analysis failures and better method transfer as well as providing an assurance of quality. This work presents the systematic development of an optimal, robust, fast UHPLC method for the simultaneous assay of two APIs of an eye drop sample and their impurities, in accordance with Quality by Design principles. Chromatography software is employed to effectively generate design spaces (Method Operable Design Regions), which are subsequently employed to determine the final method conditions and to evaluate robustness prior to validation.

► A fast and robust UHPLC method for the simultaneous assay of two APIs and impurities was developed.
► The workflow adhered to follow Quality by Design principles.
► Modern software was used to gain scientific insight and to reduce experimental workload.
► Chromatography software was used to model retention behavior and to visualize robustness.
► A novel software module was used for 6 factor robustness evaluation and tolerance determination.