Differential scanning calorimetry: A screening tool for the development of diacerein eutectics

Abstract

The application of DSC technique has been employed for better understanding the behavior of multi-component solid forms of poorly water-soluble drugs. Therefore, the purpose of the present work was to investigate the binary system of Diacerein (DIC) by preparing multi-component adducts using various coformers. DIC and different coformers were co-grounded with various solvents at 1:1, 2:1, and 1:2 M ratios. These solid forms were characterized using DSC, PXRD, FT-IR, and SEM. DSC analysis preliminary characterized that aliphatic and phenolic acid are competent enough to co-crystallize with DIC with lower melting endotherms via acetone assisted grinding method. The results of PXRD, FT-IR, and SEM confirmed the formation of two novel eutectics of DIC with fumaric acid (FUM) and 2, 4-dihydroxybenzoic (DIH) acid. Two eutectics, i.e., DIC-FUM (1:2) and DIC-DIH (1:3) with exact stoichiometry were further identified by using Tamman’s triangle. The representative samples were subjected to kinetic solubility measurements. Both the produced eutectics showed superior solubility compared to DIC alone with their stable nature. Hence, a low melting depression eutectic could be resolved via DSC analysis applied as a diagnostic tool in designing the multi-component solid forms of the targeted drug molecule.