Synthesis and Spectroscopic Characterization of Co-Crystals of Fluconazole with Succinic Acid and Urea as Coformer

Abstract

Co-crystal engineering is an important aspect of pharmaceutical development as it enables the obtainment of structural varieties of drug forms of same active pharmaceutical compounds while maintaining or improving physico-chemical and therapeutic activities of the active pharmaceutical compounds. In this work, we report the green synthesis of two co-crystals of fluconazole with succinic acid and urea. White block single crystals were obtained after slow evaporation of ethanolic solution of fluconazole (FLU) with the coformers (succinic acid and urea) in 1:1 molar ratio and were characterized using UV and Fourier Transform Infrared (FTIR) spectroscopy. FTIR spectra of the co-crystals confirms the formation of the co-crystals in solid state with the appearance of diagnostic FTIR bands of both fluconazole functional groups and those of the coformers (succinic acid and urea) in succinic acid-fluconazole (SFLU) and urea-fluconazole (UFU) respectively. UV-Vis spectra also features the π-π* absorption maxima of fluconazole in the co-crystals, providing additional evidence for the formation of the co-crystals.