Radiochemical Purity and Stability of Commercial ^99mTc-Stannous DTPA Kits Using a New Chromatography Technique

Abstract

The radiochemical purity and stability of four commercial ^99mTc-stannous diethylenetriaminepentaacetic acid (^99mTc-Sn-DTPA) kits were evaluated. A chromatographic technique involving Gelman instant thin layer chromatography was utilized to distinguish between ^99mTc-Sn-DTPA, ^99mTc-pertechnetate (^99mTcO₄ –), and hydrolyzed reduced ^99mTc (^99mTc-HR). The radiochemical purity of the kits was consistently greater than 99.0% on the two consecutive days evaluated. The stability of the commercial kits was greater than 99.0% at 4 hr after preparation. However, breakdown of two commercial kits was observed 6 hr after radiopharmaceutical preparation. These kits had radiochemical purities of 85.7 and 86.6% at 6 hr after preparation.