Preparation and Characterization of Aripiprazole Cocrystals with Coformers of Multihydroxybenzene Compounds

A novel co-crystal of aripiprazole (ARI), the active substance in the atypical antipsychotic Abilify, with orcinol (ORC) as a coformer, was prepared, characterized, and compared with other ARI co-crystals with dihydroxy- and trihydroxy-benzene coformers [catechol (CAT), resorcinol (RES), and phloroglucinol (PHL)] reported previously (Nanubolu, J. B.; Ravikumar, K. CrystEngComm 2016, 18, 1024–1038). Three preparation methods were used: neat grinding (NG), liquid-assisted grinding (LAG), and solvent evaporation (SE). Based on single-crystal X-ray diffraction (SC-XRD) measurements, the crystal structure of the ARI–ORC co-crystal was determined to be monoclinic. The melting point of ARI–ORC co-crystal was found to be 184–185 °C, higher than existing ARI co-crystals with multihydroxybenzene coformers. Additionally, the ARI–ORC co-crystal showed the highest dissolution rate among those in the test group in an acetonitrile–water 10/90 cosolvent. We investigated how the co-crystallization pathway and the dissolut...