Preparation and purity determination of radiolabeled taxol and evaluation of its absorption in murine melanoma

Taxol is a known substrate for P-glycoprotein, which induces drug resistance to cancerous cells. Therefore radiolabeled taxol can be a suitable probe for imaging of the P-glycoprotein transport ability to determine drug resistance. The aim of this study was to provide labeled taxol and to determine the rate of uptake in the tumor to evaluate the location of the tumor and the extent of tumor resistance to the drug.

Taxol was radiolabeled with 99mTc by direct labeling method and after that radiochemical purity of complex was investigated. The stability and biodistribution of radiocomplex in the mice bearing melanoma tumor was performed.

The radiocomplex was prepared with radiochemical purity more than 90%. The complex was stable (68.64%) up to 48 h. The biodistribution results showed high tumor uptake (4.51%ID/g) for radiocomplex.

High uptake of the complex in the liver as a metabolic and excretory organ and a related tumor was observed. The accumulation of radioactivity in the tumor indicates that the cells in the melanoma tumor are susceptible to taxol absorption and it is possible to detect the sites involved with the tumor using this radiocomplex. In general, based on the findings, it can be concluded that the compound has binding affinity to the tumor and, despite the biliary excretion, can be used as a diagnostic radiopharmaceutical.