The present invention relates to novel salt forms of 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine, a DPP-4 inhibitor and their use in pharmaceutical compositions useful in the treatment of type 2, diabetes, as well as their production.