Study on the reaction kinetics of 99Tcm-labeled BIDP

A novel zoledronic acid derivative, 1-hydroxy-2-(2-butyl-1H-imidazole-1-yl)-ethylidene-1,1-diphosphonic acid(BIDP), was synthesized and labeled with <'99>Tc<'m>. The detailed kinetic study on the labeling reaction between BIDP and <'99>Tc<'m> was carried out. The results indicated that the reaction rote constants k were 0.0258, 0.0268,0.0305, 0.0323, 0.0351 and 0.0384 min<'-1> at 0℃, 5℃, 10℃, 15℃, 20℃ and 25℃, respectively. From the Arrhenius equation k=-A.e<'-Ea/(Rr)>, the activation energy Ea of the labeling reaction was calculated to be 10.45 kJ/mol. And the correlation between k and temperature(T) was also deduced as In k=1258.8×(1/7)+0.9531. In addition, it was found that in order to get a high radiolabeling yield(RLY)(>90%), the reaction temperature must be up to 12℃.