Solid-core technology is becoming increasingly popular for UHPLC/HPLC separations. This seminar examines the theory behind the increased efficiency, faster analysis and lower back pressure claims. It will demonstrate how reduction in band broadening with these phases enables chromatographic separations to be performed in most cases, with increased resolution and higher sensitivity, compared to fully porous phases. We then continue by discussing practical aspects for rapid method development with optimized workflows allowing a better understanding of how to develop faster HPLC/UHPLC analyses. Example separations for various compound classes and analyte mixtures are shown to demonstrate these parameters. We also consider pH as a key variable in our method development protocols. Some consideration will be made to the transfer of methods from fully porous to solid-core particles.