Abstract
1152
Objectives Several attempts have been performed in order to label somatostatin analogues with 99mTc, which is the most available radionuclide. Tektrotyd (99mTc-EDDA/HYNIC-Tyr3-Octreotide) scintigraphy seems to have significant sensitivity and specificity in GEP’s.1 We report the daily quality controls of this pharmaceutical introduced in our Department.
Methods We perform physicochemical tests, indicate the level of radionuclidic and radiochemical impurities, determine of pH and visual controls. The biological tests (sterility and apyrogenity) performed periodically by an external official laboratory, which checks the QA of our Department. For these controls, the pHmetric papers, the ITLC strips, the solvents or other solutions are described on the product SPC / package insert2. The ITLC’s strips are counted in a well counter.
Results We study the labeling procedure using a radioactivity range from 40 mCi to 75 mCi, different volumes from 0.9 ml to 1.7 ml, different temperatures in heating procedure 80 oC, 90 oC, 100 oC of different times 20 min, 22min, 25min, 30 min. The radiochemical purity was between 91% - 98%. After the quality control, we release the pharmaceutical and the administration takes place. The residual activity was measured after each administration. For the specific protocol the injection dose is 10 mCi to 25 mCi. The residual activity was measured in order to calculate the exact injected dose and was 3- 5 mCi.
Conclusions We concluded that conditions 75 mCi, in 1.0 ml, heated up to 90 oC for 22 min, give radiochemical purity 98%. These conditions allow us high specific activity, good labeling percentage and high quality imaging under the suggested protocol. We can also administer two patients to achieve abetter cost effective preparation - scintigraphy. Reduction in dosages have significant role to the imaging quality, therefore we inject higher dosages and wash carefully the syringe due to high residual activity. Our release criteria include batch and dose labeling (radioactivity at preparation, time of use and expire time), radiochemical purity, pH, appearance (clear, colorless, free of particulates).