Biodistribution of labeled rifampicin in animals
The Institutional Animal Ethical Committee approved the study, and the treatment of the animals was carried out in accordance with the Committee for the Purpose of Control and Supervision of Experiments on Animals’ recommendations (CPCSEA). Wistar rats (n=12) weighing 150-250 g were orally administered 4mg/kg rifampicin dissolved in 1ml of vehicle containing 100-200 µCi of activity of 99mTc. “Tissues and organs were excised from the rats following sacrifice by cervical dislocation at” pre-defined time points of 0.5h, 4h, and 8h post-oral administration of radiolabeled rifampicin. “Three rats were used for each time point. The radioactivity in each organ/tissue was measured” using “a flat-type solid scintillation counter (15-cm diameter) with a NaI(Tl) detector. The percentage of administrated activity (%AD) in each organ as well as per g of the tissue” was calculated. “Blood, bone, and muscle weight were taken as 7%, 6.5%, and 40% of the body weight, respectively”.