Radiolysis of 131I-O-iodohippurate: A kinetic study

✍ Scribed by C. E. Hotte; R. D. Ice; G. L. Flynn

• Publisher: John Wiley and Sons
• Year: 1980
• Tongue: French
• Weight: 395 KB
• Volume: 17
• Category: Article
• ISSN: 0022-2135
• DOI: 10.1002/jlcr.2580170515

✦ Synopsis

Abstract

Although radiolytic decomposition of several radiopharmaceuticals has exhibited apparent first‐order kinetics, the dependence of decomposition on drug concentration precludes a first‐order rate process. A kinetic study of the decomposition of ^131^I‐o‐iodohippurate in aqueous solution was carried out to accurately assess the dependence of radiopharmaceutical decomposition on absorbed radiation dose, initial radiopharmaceutical concentration and, in addition, on the concentration of added free radical inhibitors. The fraction of ^131^I‐o‐iodohippurate remaining, (A/A~o~), was found to decrease exponentially with increased absorbed radiation dose. The radiolytic decomposition rate, however, exhibited a Langmiurian relationship with respect to the initial concentration of the radiopharmaceutical present (A~o~) and the initial concentration of free‐radical inhibitor present (I~o~).magnified imagewas derived to characterize these dependencies and demonstrated good correlation with experimental results. This equation may be of value in assessing the radiolytic stability of other radiopharmaceuticals.