Exploring potential coformers for oxyresveratrol using principal component analysis

Oxyresveratrol (OXY) exhibits poor bioavailability due to its low solubility. Cocrystals are effective in improving solubility of OXY. In this study, principal component analysis (PCA) was employed for coformer selection using 5 variables (solubility parameter, logP, hydrogen bonding acceptor, hydrogen bonding donor and molecular volume). According to PCA analyses, nicotinamide (NCT) and proline (PRO) were grouped as the potential coformers. OXY-PRO and OXY-NCT cocrystals were obtained using a liquid assisted grinding method. The thermal and diffraction characteristics of both cocrystals were different from their starting materials. Based on FTIR and Raman spectroscopy, both interactions between the amide group of NCT and the phenolic hydroxyl groups of OXY, as well as π-π interactions between the aromatic rings of OXY and the pyridine ring of NCT were involved in the cocrystal formation. For OXY-PRO cocrystal, the carboxylate group of PRO interacted with the hydroxyl groups of OXY, OXY-NCT and OXY-PRO cocrystals enhanced the solubility and dissolution of OXY. Accordingly, PCA proved to be an effective technique in screening potential coformers for OXY and probably for other compounds. The improved solubility and dissolution of OXY in the form of cocrystal may provide a benefit for the use of OXY for pharmaceutical applications.