Simulated moving bed chromatographic resolution of a chiral antitussive

The behavior of a laboratory simulated moving bed (SMB) unit for continuous chromatographic separation of enantiomers has been considered. This was applied to the resolution of a chiral antitussive agent, guaifenesin, on Chiralcel OD, during an experimental campaign involving nineteen runs. The application of recently developed criteria for the design and optimization of SMB units allows us to understand and rationalize the experimental results, as well as to indicate how to optimize the separation performances. A three-step procedure to determine the adsorption isotherms needed to apply these criteria is proposed; it is reliable and may be applied also where pure components are not available.