Preparation of radioiodine labelled Rose Bengal for liver function studies

I-131 labelled rose bengal, a radiopharmaceutical labelled compound is extremely useful for studying liver scintigraphy. One popular method for the preparation of this isotropically labelled compounds is by means of exchange reaction under appropriate conditions, the exchange occurs in an acetate buffer solution between in-active carrier-free rose bengal and reducing agent free high specific activity radioiodine, pH range of 4-5 is the best. The separation of this radiopharmaceutical is accomplished by the use of the sephadex G-25 chromatographic method, it is then sterilized by aseptic Millipore filtration. The stability of this radioisotope can be determined by studying its radiochemical purity after storage under varying conditions of time and temperature