Preparation of high purity labelled Rose-Bengal with radioiodine

The exchange of Rose-Bengal in the mono-sodium salt with elementary¹³¹I in an organic medium allows for the preparation of a labelled product substantially higher in radiochemical purity than that produced by other methods. Purification of the starting material before the labelling process has been done by adsorption chromatography. Under the conditions described a radiochemical yield more than 97% can be obtained within 30–60 minutes. The product was stable during sterilization and storage for 10 days and was found to be free of¹³¹I.