New crystalline forms of 5-Chloro-3-(4-methanesulfonylphenyl)-6-methyl-[2,3]bipyridinyl in the form of stable salts and cocrystals with pharmaceutically acceptable inorganic and/or organic acids. Organic acid is selected from succinic, adipic, fumaric, benzoic, salicylic, 1-hydroxy-2-naphthoic, 3-hydroxy-2-naphthoic acid and saccharin and inorganic acid is selected from hydrochloric, hydrobromic, nitric and sulfuric acid. By the appropriate use of the salts and cocrystals described herein it is possible to modulate and ensure the consistency of the physicochemical properties of the active pharmaceutical ingredient and enable its administration in different dosage forms including for oral delivery.
