AIM
The reason of unreproducible data under diagnosis and therapy with radioiodine should be elucidated.
METHODS
The iodine content of the capsules was tested by a colorimetric method and by activation analysis. Radiochemical purity was determined by HPLC and by electrophoresis. Solubility of the capsules was investigated under different conditions.
RESULTS
The iodine content of the capsules varied between 0.8 and appr. 100 micrograms/capsule. The radiochemical purity of the capsule iodine varied between 75% and 99.5% (main contamination: iodate). The solubility of the capsules differed.
CONCLUSION
Additional non-radioactive iodine in the therapy capsules could be one reason of the reduced radioiodine-uptake under therapy.