ABSTRACT
The increasing demand for quality by design (QbD) in analytical science is a logical consequence of the often chaotic method development practices in high-performance liquid chromatography (HPLC) that result from a trial and error approach, during which stumbling over new or disappearing peaks in the ultra high-performance liquid
8.1 Introduction ................................................................................................ 331 8.2 History of DryLab Development ................................................................ 332 8.3 Knowledge Management Document Is Mainly Used for
Post-Approval Changes ..............................................................................334 8.4 Isocratic Models.......................................................................................... 334
8.4.1 Case Study 1: pH Model ............................................................... 334 8.5 Gradient Models ......................................................................................... 335
8.5.1 Case Study 2: Gradient Time (tG) Model and Development of Step Gradients .......................................................................... 335
8.6 Simultaneous Change of Two Factors-2D Models ................................... 335 8.6.1 Case Study 3 ................................................................................. 335
8.7 Which Model Is the Most Efficient? ........................................................... 336 8.8 Which Modeling Tools to Select? ............................................................... 337 8.9 Multifactorial Modeling: The 3D Resolution Cube .................................... 338
8.9.1 Case Study 4 ................................................................................. 338 8.10 How to Find the Best Column? ................................................................... 338
8.10.1 Case Study 5 ................................................................................. 338 8.11 Robustness Modeling ..................................................................................344
