Zwitterionic Cocrystals of Flavonoids and Proline: Solid-State Characterization, Pharmaceutical Properties, and Pharmacokinetic Performance

We utilized the concepts of crystal engineering to acquire cocrystals of d/l-proline with a variety of flavonoids and further evaluated the impact on solubility and pharmacokinetic of flavonoids. We have synthesized and characterized six d/l-proline cocrystals with flavonoids and their single crystal structures were revealed. The powder dissolution profiles were determined and the pharmacokinetic properties for Kae-l-Pro were analyzed and compared with the corresponding physical mixture. d/l-Proline was found to be a suitable coformer for a variety of structural similar flavonoids. This study may offer an alternative approach for the development of these widely used flavonoids.