Formation of Diacerein − fumaric acid eutectic as a multi-component system for the functionality enhancement

Abstract The present study aimed to enhance physico-mechanical properties of poorly soluble drug Diacerein (DIA) using crystal engineering approach. Fumaric acid (FMA) was competent enough to generate a novel solid form of DIA by acetone assisted grinding method and was fully characterized. A lower melting depression and maximum enthalpy of fusion resulted from phase diagram and Tammann's triangle of binary system revealed the formation of eutectic mixture with molar ratio of 1: 2 (DIA: FMA). It was further confirmed by PXRD and FT-IR spectra. The topographical differences were observed in case of eutectic by SEM analysis imparting its better flow and packability. Pharmaceutical behaviors in terms of solubility, dissolution, tabletability, compressibility and stability suggested superior functionality of eutectic compared to DIA alone. Pharmacokinetic study of eutectic demonstrated 1.77 times greater bioavailability. Thus, the concept of crystal engineering was successful to prepare DIA-FMA eutectic as a potential way for improving material functionality.