The purpose of the study was to label Flixotide (TM)(fluticasone propionate [FP] with HFA propellant), with technetium-99m and validate that Tc-99m acts as a suitable marker for FP when delivered via pMDI-spacer. Sodium pertechnetate was mixed with 5 mL of butanone. Tc-99m was extracted into butanone and transferred into an empty canister. The Tc-99m lined canister was heated, and the butanone evaporated to dryness. A supercooled commercial Flixotide (TM) canister was decrimped, and the contents transferred to the Tc-99m lined canister and recrimped. The particle size distribution of FP and Tc-99m from 10 radiolabeled canisters was measured using an Anderson cascade impactor calibrated to 28.3 L/min, and compared to commercial FP. The drug (FP) content of each particle size fraction was measured using ultraviolet spectrophotometry and the Tc-99m level in each fraction was measured using an ionization chamber. The percentage of particles in the fine particle fraction (< 4.7 mu m) and the percentage of 99mTc from commercial and radiolabeled canisters were compared. The mean (SD) % FP in the fine particle fraction, before and after label was 43.2 (1.8) % and 43.9 (2.6) %, respectively. The mean (SD) % Tc-99m in the fine particle fraction was 42.1 (5.1) %. The mean %FP exiting spacer at (< 4.7 mu m) before labeling was not significantly different from the mean % FP exiting spacer at (< 4.7 mu m) after labeling (p > 0.05). The mean % Tc-99m attached to particles at (< 4.7 mu m) after radiolabeling was not significantly different from the mean % FP levels (P > 0.05). The validation in this study indicates that Tc-99m can act as a suitable marker for HFA-FP, delivered via pMDI-spacer.
|Journal||Journal of Aerosol Medicine and Pulmonary Drug Delivery|
|Publication status||Published - 2006|