LABELLING OF SOME PHARMACEUTICAL COMPOUNDS WITH RADIOIODINE

Abstract

Electrophilic radioiodination of three of medically important compounds namely, pindolol (PIN), benzamide (S(-)BZM) and lisuride (LIS) was carried out by using several oxidizing agents such as chloramine-T, iodogen, iodine monochloride at room temperature and hydrogen peroxide at 100 °C. The factors affecting the percent radiochemical yield such as substrate concentration, pH, oxidizing agent concentration, reaction time and the concentration of KI carrier were studied. The conditions, which gave high radiochemical yield, were summarized in one reaction to give the optimum radiochemical yield. Optimization of the radiochemical yield resulted in 90% for radioiodobenzamide (*IBZM) when the reaction was carried out in O.lM phosphate buffer (pH =3) or in ammonium acetate buffer (pH= 4) for 5 minutes reaction time. A radiochemical yield of 50% of *IPIN was obtained when the reaction was carried out in O.lM phosphate buffer (pH =7) for 30 min. A radiochemical yield of 70% of *ILlS was obtained when the reaction was affected in O.lM phosphate buffer (pH= 7) within 30 min reaction time.