Binary co-crystals of the active pharmaceutical ingredient 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene and camphoric acid

Co-crystals comprising the active pharmaceutical ingredient 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene and camphoric acid in 1:1 and 3:2 stoichiometries have been prepared and characterized by single-crystal X-ray diffraction and other physicochemical techniques.