Isostructural Multicomponent Gliclazide Crystals with Improved Solubility

This study focused on pharmaceutical isostructural multicomponent crystals and compared their physicochemical properties. Gliclazide (GLI), a drug used for treating diabetes mellitus, formed isostructural multicomponent crystals with 4-aminopyridine and 3,4-diaminopyridine. The structures of these crystals were determined by single-crystal X-ray structure analysis. These crystals were categorized as salts because they showed proton transfer. The crystal structures revealed a robust one-dimensional hydrogen bond chain of GLI by the crystallographic 2 1 screw axis along the b -axis and the interaction between these two chains, which includes the coformer, to construct a dimeric structure were crucial to the isostructurality. These salts showed a promising dissolution rate that was higher relative to that of the raw material. Interestingly, although both are isostructural, 4-aminopyridine salt showed a faster dissolution rate than 3,4-diaminopyridine salt.