Isotopic exchange method for preparation of io-dine-125-n-(1-p-nitrobenzaldhydephenyl)-2- (2-iodophenyl)-4-(4-nitrobenzilidene)-imidazolin -5-one and its biological evaluation

N-(1-p-nitrobenzaldhydephenyl)-2-(2-iodophenyl)-4-(4-nitrobenzilidene)-imidazolin-5-one was labeled with radioactive iodine-125.via nucleophilic substitution reaction, the isotopic exchange labeling process was carried out in dry state at 330oC for 20 min. The radiochemical yield was determined by using electrophoresis and the yield is equal to 93%.Ammonium sulphate was used as catalyst to facilitate the exchange reaction in melt state. Maximum heated with iodine-125 at 330oC for 20 min in a reaction mixture with pH between 6 and 8. The results referred to the importance of use NaOH in a molarity of less than 0.02M to prevent the decomposition of the produced tracer due to the change in pH of the reaction mixture. The biodistrubution pattern of the labeled compound was examined in normal as well as in tumor bearing mice and the data show high clearance from the blood as the activity remind in the blood 11.2% at 4 hours post injection. The labeled compound was extracted via liver as the accumulated activity in the liver and intestine were 14.4, 15.4% respectively at 4 hours post injection The biodistrubution of labeled compound in tumor bearing mice accumulation in ascites with high percentage equal to 55.3 % at 24 hours post injection. This demonstrate the ability of this tracer concentrate in tumor site which primate its possible application as therapeutic agent. Keywords: Imidazoline Derivatives, Isotopic Exchange Method, Tumor Targeting, Tissues Distribution.