A simple method of preparation for [123I]-(S)-(-)-IBZM

Sterile, apyrogenic [123I]IBZM was prepared in a sealed, capped 'V' vial, followed by SEP-PAK C-18 cartridge purification, and then was placed under sealed vial condensation. The quantity of BZM present in the final product ranged from 3.3-5.9 micrograms, as measured by a UV spectrophotometer at 254 and 308 nm. Animal biodistribution studies revealed that the [123I]IBZM prepared by this method which contained 5.9 micrograms of BZM, compared to the standard preparation method containing 0 microgram of BZM, resulted in identical brain uptakes at 15, 30, 60, and 120 min post-injection. The in vitro and in vivo studies demonstrated that a small amount of BZM presence in the final product did not affect the radiochemical purity, nor the D2 receptor binding capacity in the rat brain of [123I]IBZM. The preparation time can be shortened to 1.5 h compared with at least 2-4 h needed for the standard method of preparation. This factor may be important in routine clinical application.