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Vol . 8 No. 3 June 2000  

Radiopharmaceutical Kits

Radiopharmacy is a multidisciplinary field in which pharmaceuticalInflascint in vivo kit chemistry, physics, biophysics, and biology are involved to develop the drugs that play a pivotal role in the research and clinical nuclear medicine. The diagnostic efficiency and efficacy of the radiopharmaceutical used is determined by different quality control procedures. DRDO has developed several new radiopharmaceuticals, which exhibit their high clinical value. Two types of radiopharmaceuticals are: {a) Non-specific which tells about the location and size of diseased lesion and {b) Specific, which also gives precise information about the nature of such lesions {e.g., Tc-99m-M-DMSA, Tc-99m-HigG, Tc-99m-Dextran, Tc-99m-Citrate). Interestingly, the last one is an alternative to 67-gallium citrate, which is most widely used but not available indigenously for infection and tumor imaging. Encouraged by the results in patients, cold lyophilized kits have been developed to produce quality radiopharmaceutical at the site of use when mixed with the requisite amount of a radioisotope, Tc-99m. During the formulation of the cold kits, good manufacturing practices, as are applicable to schedule C and C drugs, are strictly fol1owed so that quality is in-built in the preparations. Kits are lyophilized and reconstituted at the time of intended clinical applications. While reconstituting the cold kits with the radionuclides. good raDIATion safety practices are followed. After obtaining clearance from the Local Ethical Committee & National Nuclear Medicine Committee, DRDO has successfully used these radiopharmaceuticals for the diagnostic nuclear medicine procedures. Multicentric clinical trials are planned to be carried out.

The following new radiopharmaceuticals have been developed recently in the instant kit form for imaging of
different diseased lesions and are being successfully used on human patients:
Tc-99m-(V)-DMSA              Soft tissue tumour and metastasis
Tc-99m-hlgG                      Inflammation, infection
Tc-99m-Dextran                Lymphoscintigraphy
Tc-99m-Citrate                  Inflammation
Tc-99m-Glucaric Acid       Avascular necrosis, tumour
Tc-99m-Itc-Bz-EDTMP       Skeletal imaging

In the fast changing scenario, the efforts in the world-over are directed to develop specific radio pharmaceuticals. This can be achieved when radiopharmacy is blended with molecular biology to help in understanding the diseased processes at the molecular level. Efforts have been initiated in this direction also. Tc-99m ciprofloxacin, a radiopharmaceutical for specific infection imaging has been developed. Presently, R&D work is in progress in several areas, including development of infection-specific radiopharmaceuticals for diagnosis of tuberculosis, production of nanoparticles/microemulsions as a carrier of radiopharmaceuticals, development of receptor-specific radio pharmaceuticals, radio labelling of new bifunctional chelating agents and their evaluation for therapy of cancer, development of radiopharmaceuticals for studying atheroscelerosis, and development of magnatopharmaceuticals.