Optimization of the reaction conditions for the preparation of 99mTc-celecoxib and its biological evaluation

Celecoxib was labelled effectively with ^99mTc. The labeling yield was found to be influenced by the amount of celecoxib, the amount of stannous chloride dihydrate, the reaction time, the temperature and the pH of the reaction mixture. The importance of stannous chloride dihydrate arises from its function as a reducing agent for pertechnetate to form complex celecoxib. The suitable amount required to produce high labeling yield of ^99mTc-celecoxib was 500 μg SnCl₂·2H₂O. The pH of the reaction medium was found to play a significant role in this labeling process. The labeling reaction was performed at a neutral medium (pH 7). The labeling reaction proceeds well at room temperature (25 ± 1 °C) and the complex decomposes by heat. The labeled celecoxib (^99mTc-celecoxib) showed a good localization in inflamed foci and a good imaging must be taken 4 h post injection.