The present invention relates to the use of novel vildagliptin complexes for the manufacture of high purity vildagliptin of Formula I and/or pharmaceutical acceptable salts thereof. Further objects of the present invention are pharmaceutically acceptable complexes of vildagliptin and/or amorphous and crystalline forms, anhydrous forms, amorphous and crystalline hydrates, amorphous and crystalline solvates of the complexes and a process for the preparation thereof. Another object of the present invention is the high purity vildagliptin and pharmaceutically acceptable salts thereof prepared form the vildagliptin complexes of the present invention, a process for the preparation thereof and pharmaceutical compositions containing vildagliptin base, pharmaceutically acceptable salts and/or complexes and use thereof for the treatment of type 2 diabetes (NIDDM). The present invention provides pharmaceutically advantageous high purity vildagliptin complexes.