Optimization of Hot-Melt Extrusion Processing for the Synthesis of Ionic Cocrystals

Cocrystals are multicomponent crystalline forms that are an appealing alternative to modify undesirable properties of drug substances, such as poor solubility and stability. Hot-melt extrusion (HME), a solvent-free, robust, and scalable technology, has been proven to be a suitable approach for cocrystallization of several drug-coformer pairs. However, HME has been mainly implemented for the synthesis of molecular cocrystals when most of the marketed products are manufactured in the form of ionic cocrystals. In this study, the synthesis of extruded fluoxetine HCl-succinic acid cocrystals was investigated using different screw configurations. Ionic cocrystals manufactured by HME showed complete transformation of the drug-coformer pair with high purity, improved intrinsic dissolution rates, and long-term storage stability when compared to their counterparts produced by solvent evaporation.