Electrolytic technique for labeling adriamycin with Tc-99m

This paper reports on a technique for the labeling of doxorubicin hydrochloride (Adriamycin [ADM]) with Tc-99m that was developed. Two milligrams of ADM hydrochloride salt and 1-3 mL of Tc-99m pertechnetate in physiologic saline solution were placed in a 10-mL vial with two tin electrodes inserted through a rubber septum. A 1-mA current was passed through the solution for 3 minutes. Labeling efficiency of 97.7% ± 0.5 was determined by thin-layer chromatography. Also, 111 μg time was generated in situ during the electrolysis procedure. Repeated chromatography during a 24-hour period indicated that Tc-99m was firmly incorporated into the ADM. Biodistribution studies in normal rats injected with Tc-99m-ADM demonstrated rapid liver uptake, slow hepatobiliary clearance, and minimal renal excretion, this is similar to the biodistribution of unlabeled ADM