Structural characterization and in-situ synthesis of quaternary ionic-cocrystal of isoniazid from un-ionized coformers

Abstract

Abstract Isoniazid is an important antitubercular compound and part of fixed-dose combinations (FDCs) that renders poor chemical stability to solid state form and has proved itself as a compound that successfully gives cocrystals with carboxylic acid derivatives. Cinnamic and benzoic acids having antioxidant and antitubercular activity, may lead to crystalline new solid form with improved pharmaceutical properties. Ionic-cocrystal is a recent and relatively undiscovered solid form with academic and industrial interest. In this study we report an ionic-cocrystal of isoniazid with carboxylic acid derivatives having four different molecules (INH, 2,5-dihydroxybenzoic acid (25DHBA), 2,4-dihydroxycinnamic acid (24DHCA) and a Water molecule) in a single crystal. The synthesized Ionic-cocrystal is characterized by IR, PXRD, solid-state NMR and single crystal XRD.