Background: A convenient method was developed for the preparation of pentavalent 99mTc dimercaptosuccinic acid using a commercially available meso-2,3-dimercaptosuccinic acid (DMSA) kit. The effects of various parameters, including incubation time, pH, and concentration of sodium bicarbonate on radiochemical purity (RCP) yield were evaluated. To determine tri- and pentavalent fractions, RCP yield of the labeled DMSA was measured using different solvent systems. Methods: The RCP yield was studied using a thin-layer chromatography on silica gel as the stationary phase and n-butanol/acetic acid/distilled water (3:2:2) as the mobile phase. Results: It was observed that hydrolyzed 99mTcO2 and 99mTc(III)-DMSA remained at the origin (Rf = 00.1), and 99mTc(V)-DMSA at (Rf = 0.50.6), while free pertechnetate, 99mTcOâ4 moved to the solvent front (Rf = 0.91). However, in acetone, 99mTc(III)-DMSA, 99mTc(V)DMSA, and hydrolyzed 99mTcO2 stayed at the origin (Rf = 00.1), while free pertechnetate, 99mTcOâ4 moved to the solvent front (Rf = 0.91). When developed with 5% glycine, 99mTcO2 stayed at the origin and the other species migrated to the solvent front. The labeling efficiency of the 99mTc(V)DMSA was 96.6± 0.5% and was stable for 24 hours at room temperature. Conclusion: Higher labeling yield, easy preparation with low cost, and good stability make 99mTc(V)-DMSA, a promising radio drug for clinical use.
Medullary thyroid cancer, 99mTc(V)-DMSA, radiochemical purity, thin-layer chromatography.