Quality control methods for ^99mTc‐labeled exogenous natural surfactant (^99mTc‐ENS)

Abstract

SummaryTo standardize the quality control for 99m Tc-ENS, the following methods were studied: (1) physical properties and pH, (2) radiochemical purity (chromatographic studies on Whatman-1 paper, or instant thin-layer chromatography and solvent extraction using different solvents and (3) rat biodistribution studies by intratracheal injection. The tolerance limits were fixed for each method. The radiopharmaceutical stability was also evaluated. The results showed that 99m Tc-ENS was a white suspension with a pH between 4.0 and 6.0. The limit for radiochemical impurities in Whatman-1 paper/acetone was fixed at lower than 2% and the established limit for the organic aliquot in cyclohexane extraction was greater than 2%. In the biodistribution studies, the limits for activity concentration were fixed at greater than 90% for lungs, less than 9% for the gastrointestinal system and less than 1% for the sum of the other organs studied. After a storage time of 6 h at room temperature or in a refrigerator, 99mTc-ENS physical properties and pH, radiochemical and biodistribution results were within the established values. In conclusion, the quality control methods for 99m Tc-ENS are tests on physical properties and pH, radiochemical purity by Whatman-1 paper/acetone chromatography and cyclohexane extraction and biodistribution studies in rats. The stability of this radiopharmaceutical is at least 6 h at room temperature.

Role of the Lung Surfactant in the Treatment of Sars-Cov-2 Infection

“…Administration of exogenous surfactant has become standard therapy for infants with respiratory distress syndrome (RDS) or jaline membrane disease PROSURF has demonstrated in numerous clinical studies, using the appropriately marked product, a high distribution capacity at the alveolar level and resolution of respiratory failure. [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36], Fig. No adverse effects could be found related to the administration of surfactants.…”