99Tcm-tetrofosmin: evaluation of fractionated cold kits and two new methods of quality control.

The fractionation of Myoview into 1:5 was followed by storage at -80 degrees C for 3 months. The kits were reconstituted with 3.5 GBq 99Tcm-pertechnetate and the average radiochemical purity (RCP) was maintained at 96.5 +/- 1.6% (n = 24) for 24 h. There was no difference in biodistribution between the 1:5 fraction and the full kit, especially with respect to myocardial uptake. These observations show that it is possible to fractionate and store Myoview kits at -80 degrees C and produce a product that is stable over 3 months. This provides a cost-effective method for using 99Tcm-tetrofosmin. Two new methods of determining RCP were also examined and found to give results that were not significantly different from the recommended manufacturer's method. A mini paper chromatography (MPC) method using Whatman 17 paper and a solvent mixture of ethyl acetate: acetone (1:9) and an Amprep SAX cartridge method using absolute ethanol as the solvent were found to be more rapid and reliable methods of quality control for this product.