Formulations labeling, radionuclide

The BMEDA method shares some of the same features as the HMPAO method such as good in vitro and in vivo stability with a variety of preformed liposome formulations, and the need for coencapsulation of glutathione. In addition, an advantage of the BMEDA-labeling method is that it can also be used for labeling liposomes with therapeutic rhenium radionuclides (22). Currently, for the BMEDA method, there is no commercially available kit. Also the BMEDA chemical is not currently commercially available and must be synthesized. 

Another approach is to use kit formulations also for this kind of product. Therapeutic radiopharmaceuticals have been developed where the carrier molecule is formulated in a lyophilized kit and supplied together with the radionuclide. An example of this is the MAb ibritumomab tiuxetan formulated for labeling with the P-emitting radionuclide 90Y. Yttrium-90 ibritumomab tiuxetan (Zevalin) is used in the treatment of non-Hodgkin s lymphoma (NHL). 

Before performing an in vivo study, in vitro testing must be used to see if the intended function of the radiolabelling has been met and that the properties of the formulation are unaffected by the labelling. In these tests, the amount of radionuclide released from the... 

Radionuclides suitable for labelling of formulations, including decay half-life (l1/2) and peak photon energy. 

Identity and purity, stability, and sterility and apyrogenicity. The identity and purity of radiopharmaceuticals is verified by determining the radionuclidic and radiochemical purity. Stability concerns the radioactive label, which is related to radiochemical purity at a certain time after preparation. Since Tc pharmaceuticals are formulated as sterile, pyrogen-free solutions, the safety requirements of drugs for parenteral use do apply. Safe handling of the radionuclide is equally important and must comply with Euratom Directives, regulated by national law for radiation protection, which also concerns the application of radionuclides in adults and in children for diagnostic procedures. 

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