In vivo distribution of Tc-99m(Sn)pyridoxylideneisoleucine: effects of storage and labeling conditions. Concise communication.

Various conditions for the storage of the stannous pyridoxylideneisoleucine (Sn-P.isoL) kit reagent, and also for the preparation of Tc-99m(Sn)P. isoL, have been evaluated experimentally using rats. Both the frozen (-30 degrees C) and the freeze-dried state were found to be suitable for storage of the kit reagent. For the labeling procedure, at least 40 min incubation time (Sn-P.isoL + 99mTcO4-) was necessary at room temperature, but the same superior results could be obtained quickly by heating the mixed solution for 2 min in a boiling-water bath. The pertechnetate could be added in a volume up to four times that of the kit reagent. MoVI) and/or AI(III) in the pertechnetate solution did not interfere with the formation of Tc-99m(Sn)P.isoL up to the highest tested concentration of 40 micrograms/ml each.