Synthesis, crystal structure, and solubility study of a supramolecular assembly cocrystal formed by levofloxacin and nicotinic acid

•A novel cocrystal structure of levofloxacin and nicotinic acid is proposed.•The cocrystal exhibits unique properties of thermoanalysis, fourier transform infrared spectrum and X-ray powder diffraction spectrum.•An obvious advantage in improving the water solubility, that is 5.02 times higher than the original levofloxacin, was exhibited by the cocrystal.