Chiral Resolution of RS-Oxiracetam upon Cocrystallization with Pharmaceutically Acceptable Inorganic Salts

Ionic cocrystals (ICCs) of racemic RS-oxiracetam and of its active S-enantiomer of pharmaceutical interest with the pharmaceutically acceptable salts calcium and magnesium chloride were synthesized and structurally characterized. The cocrystallization of RS-oxiracetam with MgCl2 resulted in chiral resolution with formation of an S-OXI·MgCl2·5H2O/R-OXI·MgCl2·5H2O conglomerate. Ternary phase diagrams of RS-oxiracetam/inorganic salt/solvent were constructed to determine the overall compositions for which the ICCs are the only stable phases in suspension. In addition, single crystals of S-oxiracetam were grown, and its structure was determined