Labeling of famotidine with Tc-99m and biodistribution studies on rats

Famotidine, a gastrointestinal drug was labeled with Tc-99m and its radiopharmaceutical potential was observed on male Albino Wistar rats. Labeling yield was over 95%. Average specific activity and n-octanol/water partition coefficient (lipophilicity) were approximately 74 MBq/mg-0.66 GBq/mg and 3.4, respectively. Biodistribution studies were performed on Albino Wistar rats. The activity per gram tissue was calculated and time activity curves were generated. The majority of the activity was observed in stomach, small intestines and kidneys. Liver and kidneys showed lower uptake compared to other H-2-receptor rich tissues. Results show that Tc-99m-famotidine is H-2 receptor specific.