Assessment of TLC and Solvent Extraction methods in quality control of 99mTc-MIBI

Background: Technetium-99m-2-methoxy isobutyl iso nitrile (99mTc-sestamibi) is a radiopharmaceutical that can be useful in the evaluation of patients with myocardial problem.Method: We used a 10-minutes boiling water bath to prepare the 2-methoxyribonitrile isonitril kit. And to access the efficiency of labeling, the quality control procedure was performed with 2 recommended methods. In the solvent extraction method, we mixed the same concentrations of normal saline and chloroform (1:1), and then a small amount of 99mTc-sestamibi added to it and was shaken by vortex for 1 minute. Finally, two liquid phases were separated and were counted by dose calibrator. Another method for analyzing the radiochemical purity of 99mTc-sestamibi is TLC (thin Layer hromatography). We used silica gel sheet in a normal saline liquid column and Whatman- 3 sheet in a methanol liquid column. The procedure was followed up by cutting of the strips into two sections and measuring radioactivity distribution by dose calibrator.Result: An average of percentage of radiochemical purity of 99mTc- sestamibi in solvent extraction and TLC methods are 85.03±13.36, 96.95±3.74 and correlation of them are (r=0.57).Conclusion: Due to the high accuracy of the chromatography method and according to the results of our study, Chromatography is preferred to determine the quality of the 99mTc- sestamibi kit.