Cyclosporine Purification Using Liquid-Liquid Chromatography

The objective of this study was to pre-purify crude cyclosporine with an initial HPLC purity of 81.4%. The separation was performed on a 35ml miniLiLi column in ascending mode with extrusion. The solvent system enabled fine separation of apolar impurities before collection of the main cyclosporine fraction. More polar isomers were subsequently removed during the extrusion stage. The main fraction was recovered with a 71% yield, after which crystallisation increased the cyclosporine purity to the required quality. The CPC step served as an effective industrial pre-purification stage before the final high-selectivity purification or crystallisation step. Key result: CPC separated both apolar and polar impurities from crude cyclosporine and recovered the main product fraction at 71% yield, preparing it for final polishing.