The invention relates to a composition comprising a non-ionic X-ray contrast agent in a pharmaceutically acceptable carrier, and particularly to a supersaturated X-ray composition comprising X-ray contrast agents with a high dissolution temperature in water. Particularly, the invention provides such composition which is stable, and wherein crystallisation during storage is avoided. In a preferred aspect the X-ray contrast agent is Ioforminol and the composition includes a nucleation-and growth inhibitor. The in vention further relates to a process for the preparation of such stable diagnostic X-ray composition.
