Process for the preparation of crystalline and solvent-free iohexol

An industrial-scale process for the purifn. and removal of residual solvents from the X-ray contrast agent iohexol is presented which is based on the suspension of cryst. iohexol, eventually contg. residual solvents above 100 ppm, in a fluid where it has a low soly. (e.g., EtOH), followed by heating, filtration, and drying. The process allows the formation of cryst. iohexol with a residual org. solvent content of .ltoreq.100 ppm and with an increased purity level.