Quality control validation for exogenous natural surfactant labeled with 99mTc.
OBJECTIVE
Exogenous natural surfactant (ENS) labeled with 99mTc shows an elevated lung specificity allowing the acquisition of high-quality images for ventilation scintigraphy.


METHODS
The methods for 99mTc-ENS quality control (physical properties, pH determination, radiochemical studies, and biologic studies) were evaluated and validated.


RESULTS
The physical properties of the nonradioactive precursor and of the radiopharmaceutical were analyzed as general descriptors of the product. The pH of the radiopharmaceutical was determined by using pH test papers, a method described and validated in the United States Pharmacopeia. Chromatographic studies performed using the acetone/Whatman-1 paper system were validated as a method to evaluate the radiochemical purity of the 99mTc-ENS. Biodistribution studies on rats after intratracheal administration were validated as a method to estimate the radiopharmaceutical biodistribution in humans.


CONCLUSIONS
The proposed method for 99mTc-ENS quality control studies and stability studies was evaluated and validated following international standards.
Calmanovici
Gabriela P
GP
Radioisotopes Laboratory, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina. gcalmano@ffyb.uba.ar
Salgueiro
María J
MJ
Leonardi
Natalia M
NM
Goldman
Cinthia G
CG
Nicolini
Jorge O
JO
Boccio
Jose R
JR
Caro
Ricardo A
RA
Zubata
Patricia D
PD
Zubillaga
Marcela B
MB
D000818:Animals; D004353:Drug Evaluation, Preclinical / Q000379:methods / Q000592:standards; D007553:Isotope Labeling / Q000379:methods* / Q000592:standards; D008168:Lung / Q000000981:diagnostic imaging / Q000378:metabolism*; D008657:Metabolic Clearance Rate; D009928:Organ Specificity; D011663:Pulmonary Surfactants / Q000032:analysis / Q000493:pharmacokinetics* / Q000592:standards; D011786:Quality Control; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000032:analysis / Q000493:pharmacokinetics / Q000592:standards; D051381:Rats; D017207:Rats, Sprague-Dawley; D013667:Technetium / Q000032:analysis / Q000493:pharmacokinetics* / Q000592:standards; D014018:Tissue Distribution
D011663:Pulmonary Surfactants; D019275:Radiopharmaceuticals; D013667:Technetium