Preparation of radioidinated L-α-methyl tyrosine by the oxidative radioiodination using chloramine-T (CAT) and iodogen (1,3,4,6-tetrachloro,-3α,
6α-diphenyl glycoluril) to generate electrophilic radioiodine has been carried out. The factors affecting the labeling yield
such as pH of the medium, reaction time, substrate and oxidizing agent concentrations have been investigated to optimize the
conditions for the preparation of radioiodinated L-α-methyl tyrosine in high radiochemical yields. Side product impurities
were observed at long reaction times and high oxidizing agent concentrations. Maximum radiochemical yields of 89.7±1.5% and
87.8±1.6% were obtained in case of CAT and iodogen, respectively. Separation and purification by high pressure liquid chromatography
(HPLC) resulted in radiochemically pure products. Using high specific activity123I, the SPECT brain imaging agent can be prepared.