Dr Varin Titapiwatanakun - Cocrystal engineering of oxyresveratrol

Oxyresveratrol (ORV) is a compound found in the heartwood of Artocarpus lakoocha Roxburgh (Moraceae). It has diverse biological and therapeutic activities covering antioxidant, anti-inflammatory, neuroprotective, antimicrobial. However, it has poor water solubility, oral availability and stability which challenge to delivery design and product development. Cocrystal engineering has been reported to be able to modify the physicochemical properties of a chemical compound and produce a superior chemical candidate for formulation design. 77 cocrystal formers with various functional groups were used for cocrystal screening via grinding, liquid-assisted grinding, solvent evaporation and slurry methods. Eight cocrystals (ORV with citric acid, glutaric acid, betaine, L-proline, isonicotinamide, nicotinamide, urea and ethyl maltol) were successfully produced and characteristic crystal properties were confirmed by powder X-ray diffraction, low frequency Raman spectroscopy and thermal analysis. The ORV-citric acid cocrystal showed enhanced solubility and permeability across the human intestinal tract. While the crystal structures of ORV-betaine and ORV-proline cocrystals were identified and solved by single-crystal X-ray diffraction. Therefore, cocrystallization could be applied to design novel parent molecules including drugs, herbal substances and vitamin for innovative delivery systems.