THE INFLUENCE OF GENERATOR ELUATE ON THE RADIOCHEMICAL PURITY OF TC-99(M)-SESTAMIBI PREPARED USING FRACTIONATED CARDIOLITE(R) KITS

The reconstitution of fractionated Cardiolite(R) kits with sodium Tc-9 9(m)-pertechnetate eluted from a wet-column Mo-99/Tc-99(m) generator r esults in a preparation that contains elevated amounts of a polar radi ochemical impurity, which is normally present in only trace amounts wh en such kits are reconstituted with eluate from a dry-column generator . A consequence of this impurity, which appears to be an organotechnet ium compound, is that it causes a positive bias in several quality con trol methods for Tc-99(m)-sestamibi, including that recommended by the manufacturer. This impurity was isolated, and its biodistribution det ermined in Wistar rats. Two alternative methods for the preparation of Tc-99(m)-sestamibi from fractionated Cardiolite(R) kits using eluate from a wet-column generator were investigated. A rapid procedure, base d an a C18 solid phase extraction (SPE) cartridge, for measuring the r adiochemical purity of Tc-99(m)-sestamibi samples, which had been prep ared using fractionated Cardiolite(R) kits, was developed and compared with two other methods including high-performance liquid chromatograp hy (HPLC). Over a radiochemical purity range of 49-98%, the values obt ained using our quality control method deviated from those obtained us ing HPLC by 1.1 +/- 1.3% (n = 26). Ln contrast to some of the rapid qu ality control methods assessed in our investigation, the SPE technique was not biased by the presence of the organotechnetium impurity. ((C) 1998 Lippincott-Raven Publishers).