Abstract:
The ferulic (FA)-niacinamide (NIC) cocrystals were prepared and the hydrogen bonds between FA and NIC in cocrystalline state and aqueous solution were studied. The solubility and UV light stability of FA-NIC cocrystals were analyzed. Infrared spectra and Hirshfeld surface analysis of FA-NIC cocrystals indicated that the FA-NIC cocrystals assembled via hydrogen bonds between FA and NIC in four locations, and the intensity of the hydrogen bonds were ranked from strong to weak as follows: III(O-H···O)>I≈II(O···H-N)>IV(O···H-C). Compared to free FA, FA-NIC cocrystals showed lower ultraviolet absorption and fluorescence intensity in aqueous solution, which confirmed that the FA-NIC cocrystals did not dissociate into individual components completely and the hydrogen bonds between NIC and FA still existed in aqueous solution. By cocrystallization with NIC, the solubility of FA increased approximately 88%, the UV light stability of FA increased 12.7%. This meant that FA was easy to be solvated and difficult to change its configuration due to the hydrogen bonds between FA and NIC in cocrystals. Namely, the solubility and UV light stability of FA were improved remarkably by cocrystallization with NIC, which was closely related to the hydrogen bonds between FA and NIC.