An adopted method for the preparation of high radiochemical purity 125I-atenolol was investigated. Direct radioiodination of atenolol was carried out using N-bromosuccinamide or hydrogen peroxide as an oxidizing agent. The reaction proceeds well within 30 min at room temperature
(25 ± 1 °C) and afforded a radiochemical yield up to 97% as pure as 125I-atenolol. Different chromatographic techniques (electrophoresis, TLC and HPLC) were used to determine the radiochemical
yield and purity of the labeled product. Biodistribution studies were carried out in normal Albino Swiss mice and the results
indicate that 125I-atenolol can be used safely as myocardial imaging agent.