Preparation of myricetin-caffeine cocrystal and its single crystal analysis

Myricetin(MYR)was cocrystallized with caffeine(CAF)by suspension and the single crystal of MYR-CAF cocrystal was cultured by slow solvent evaporation. Cocrystals obtained by two different methods were the same in crystal form after characterization with X-ray diffraction. Structural analysis of single crystal of MYR-CAF showed that its crystal system and the space group were monoclinic and P2₁/n, respectively. In MYR-CAF cocrystal, 4′-OH in ring B and 7-OH in ring A of MYR interacted with CAF at(8)C=N and(2)C=O through hydrogen bonds. In comparison to the original MYR crystal, the intrinsic dissolution rate of MYR was significantly enhanced for about 17-fold after cocrystallization with CAF.