Physicochemical properties, binary and ternary phase diagrams of ketoprofen

Compared to simulated moving bed (SMB) chromatography, fractional crystallization is a simple and economical method for enantioseparation. Therefore, the coupling of SMB chromatography and fractional crystallization is suggested for enantioseparation of racemic compounds. In this work, a nonsteroidal antiinflammatory drug, ketoprofen (Kp), was chosen to be studied. Kp was verified as a racemic compound by FTIR, PXRD, and thermodynamic calculations. To derive the condition where pure ( S )‐Kp could be crystallized from a solution, which was previously enantiomerically enriched, the binary melting phase diagram and the ternary solubility phase diagram in the mixed solvent of ethanol and water over a temperature range of 15–30°C were obtained. From these phase diagrams the eutectic point was determined as 91.6% mole percent ( S )‐Kp from the binary phase diagram and 91% from the ternary phase diagram. The results may provide valuable experiment data for the possibility of coupling fractional crystallization with SMB for Kp separation. Chirality 16:541–548, 2004. © 2004 Wiley‐Liss, Inc.