Physical-chemistry characteristic of ^99mTc-human serum albumin (HSA)-nanospheres radiopharmaceutical

Lymphoscintigraphy is one of diagnostic method which is conducted by injecting a colloidal radiopharmaceutical labeled technetium-99m which have ideally size of 100-200 nm in diameters by intradermal, subcutaneous or peritumoral route. The radiopharmaceutical movement in the lymphatic vessel can be detected from external side using gamma camera or a special probe for lymphoscintigraphy parallelly with surgery of tumor or cancer especially breast cancer. In the year of 2006 and 2007 have succeeded to be carried out designed and formulated of ^99mTc-HSA-nanospheres is representing one of the nanocolloid radiopharmaceutical which is having the biodegradable and bioavailable characters. In the year of 2008, the study was continued to study of physical-chemistry characteristic of ^99mTc-HSA-nanospheres, including radiochemical purity, pH, lipophilicity, plasma protein binding, electricity charge, stability after storage at certain temperature and in the plasmatic media. The results shows that ^99mTc-HSA-nanospheres radiopharmaceutical have radiochemical purity of 92,1 ± 2,6%, pH = 6,5 - 7, its number of lipophilicity was 0,127 ± 0,03, plasma protein binding 89,6 ± 1,2% and neutral electricity charge. After 30 minutes, it was kept at room temperature, its radiochemical purity slow down became 71%, while if it was kept at temperature of 4°C (refrigerator) after one hour the radiochemical purity still more than 90%. In vitro plasmatic stability indicated that radiochemical purity was go down drastically, started from 30 minutes later, then one hour that was 61,8% and 55,9%, and at 2, 3 and until four hours storage this value did not change significantly that was 57,8%, 51,2%, 52% and after 24 hours became 8,2%. (author)