Generic chiral method development in supercritical fluid chromatography and ultra-performance supercritical fluid chromatography

• Investigation of the effect of different parameters in chiral SFC with polysaccharide-based selectors.
• Definition of a chiral separation strategy for SFC.
• Evaluation of the strategy with a novel 20-compound test set.
• Method transfer from a conventional to an ultra-performance SFC system.

The development of chiral separation methods in pharmaceutical industry is often a very tedious, labour intensive and expensive process. A trial-and-error approach remains frequently used, given the unpredictable nature of enantioselectivity. To speed-up this process and to maximize the efficiency of method development, a generic chiral separation strategy for SFC is proposed in this study. To define such strategy, the effect of different chromatographic parameters on the enantioselectivity is investigated and evaluated. Subsequently, optimization steps are defined to improve a chiral separation in terms of resolution, analysis time, etc. or to induce separation when initially not obtained. The defined strategy proved its applicability and efficiency with the successful separation of a novel 20-compound test set. In a second stage, the method transfer from a conventional to an ultra-performance SFC system is investigated for the screening step of the separation strategy. The method transfer proved to be very easy and straightforward. Similar enantioresolution values, but slightly shorter analysis times were obtained on the ultra-performance equipment. Nevertheless, even more benefit may be expected in ultra-performance SFC when customized sub-2 μm chiral stationary phases will become available.