Disclosed herein are 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. In specific embodiments the salt is the benzenesulfonic acid, hydrobromic acid, benzoic acid, ethanesulfonic acid, fumaric acid, salicylic acid, p-toluenesulfonic acid, glycolic acid, malonic acid or 2,5-dihydroxybenzoic acid salt.
