Physicochemical properties of ¹³¹I-rutin under acidic labeling condition as a radiolabeled compound for the diagnosis of cancer

Radiolabeled rutin (¹³¹I-rutin) has potential use in future diagnosis of cancer. The physicochemical characteristics of ¹³¹I-rutin are essential in regard to its distribution and accumulation in the body. Therefore, to ensure successful delivery of a labeled compound, it is necessary to evaluate its physicochemical properties. The labeling of ¹³¹I-rutin was accomplished using the oxidation method assisted by Chloramine-T under acidic conditions. Radiochemical purity value was measured by thin-layer chromatography (TLC-SG F₂₅₄) using 100 % methanol as the mobile phase. The electrical charge of ¹³¹I-rutin was determined by the paper electrophoresis. Moreover, the lipophilicity (P) was evaluated by the partition coefficient in the organic-water liquid. Plasma protein binding was determined in vitro by precipitation method using a 5 % trichloroacetic acid (TCA) solution. The results showed that ¹³¹I-rutin has a neutral charge and a lipophilicity value (Log P) of 0.395±0.203 (hydrophilic), and was bound to human blood plasma proteins with a percentage of 69.36 % ± 1.88 %. (author)