|On-line coupling of RPLC and chiral SFC for the analysis of pharmaceutical compounds
|Comprehensive Chromatography - The State of the Art
|Ms Marion Iguiniz
|Mrs Estelle Corbel
Mr Nicolas Roques
Dr Sabine Heinisch
|Institut des Sciences Analytiques, UMR5280, Université de Lyon, 5 rue de la Doua, 69100 Villeurbanne
Abstract Information :
For pharmaceutical industry, quality is of prime importance and has to be managed from the early stages of drug the second enantiomer should be considered in the same manner as for other impurities. It is therefore necessary to develop, at least, two independent separation methods. A RPLC method is generally used to assess the achiral purity while a chiral method is used to evaluate the enantiomeric purity.
In the recent decades two-dimensional (2D) chromatography has emerged as a valuable tool for pharmaceuticals, biomedical research, and other fields. In particular, 2D-LC has been successfully applied to the achiral−chiral analysis of pharmaceuticals since the end of the 1980's. However, most part of chiral methods were developed in normal phase liquid chromatography and that is a problem for the implementation of a 2D-LC system. Indeed, the incompatibility of RPLC and NPLC mobile phases makes this approach very challenging. We therefore investigated SFC instead of NPLC as second chiral dimension for the RPLC x SFC separation of drugs. In addition to being a greener technique, SFC is more versatile than NPLC and leads to much faster analysis times, suitable for a second dimension in comprehensive 2D-LC.
This study was carried out with a pharmaceutical sample in the early stages of development, provided by Oril Industrie. First part of the study was dedicated to the development of the chiral SFC second dimension, the first dimension of the 2D system being the method used for quality control of the pharmaceutical sample. We studied the effect of injecting polar sample solvent into a supercritical mobile phase, as well as experimental and instrumental aspects related to the interface of the system. It was very interesting to notice that the use of water as co-solvent additive allowed to increase the injected volume in second dimension, without peak distortion issues. The operating conditions were then optimized with a view to implement a 2D system in selective comprehensive mode (sRPLCxSFC), using chiral SFC in the second one. Finally the developed sLCxSFC system was successfully applied to the achiral-chiral analysis of the pharmaceutical sample.
These results allowed us to obtain both chemical and enantiomeric purity of an active principle ingredient in one single analysis.