An investigation of factors that might influence the radiochemical purity and stability of 99mTc-MAG3.

Technetium 99m mercaptoacetyltriglycine (99mTc-MAG3) was prepared from a commercial kit by various techniques to assess the effect of a number of variables on radiochemical purity and stability. Its radiochemical purity was determined by high performance liquid chromatography at 0 and 6 h after preparation and was found to be consistently greater than 95%. It has been demonstrated that the radiochemical purity of 99mTc-MAG3 prepared according to the manufacturer's instructions is not influenced by the volume of 99mTc generator eluate used, agitation, the presence of air in the reaction vial or the use of a 99mTc generator eluate with a 99Tc:99mTc ratio of 16:1. A modified method of preparation in which the MAG3 kit is reconstituted with saline before addition of 99mTc-pertechnetate has been shown to yield a satisfactory product and should help to minimise the radiation dose to the fingers of radiopharmacy staff.