The in vitro stability of [131I]o-iodohippurate

The kinetics of [131I]o-iodohippurate (OIH) decomposition were evaluated to develop an accelerated technique for the prediction of radiopharmaceutical stability. Decomposition due to temperature and self-absorbed radiation was characterized simultaneously. Using the proposed technique, the extent of OIH decomposition was calculated a priori to be 7.6% over a 28-day period when extrapolated to a specific concentration of 2 mCi/ml and a storage of 25 degrees C. Extended storage under these same conditions yielded a mean decomposition value of 8.0% over an equivalent time interval. The techniques developed offer a rapid means of accurately assessing the stability of new radiopharmaceuticals as they are developed.