Premium
Radiolysis of 131 I‐O‐iodohippurate: A kinetic study
Author(s) -
Hotte C. E.,
Ice R. D.,
Flynn G. L.
Publication year - 1980
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/jlcr.2580170515
Subject(s) - radiolysis , chemistry , decomposition , aqueous solution , kinetics , radiochemistry , radiation chemistry , nuclear chemistry , kinetic energy , chemical process of decomposition , chemical stability , chemical reaction , organic chemistry , physics , quantum mechanics
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 ).was 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.