title: Quality control validation for exogenous natural surfactant labeled with 99mTc.
abstract: 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.
authors.affiliation: Radioisotopes Laboratory, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina. gcalmano@ffyb.uba.ar
authors.forename: Gabriela P
authors.initials: GP
authors.lastname: Calmanovici
authors.forename: María J
authors.initials: MJ
authors.lastname: Salgueiro
authors.forename: Natalia M
authors.initials: NM
authors.lastname: Leonardi
authors.forename: Cinthia G
authors.initials: CG
authors.lastname: Goldman
authors.forename: Jorge O
authors.initials: JO
authors.lastname: Nicolini
authors.forename: Jose R
authors.initials: JR
authors.lastname: Boccio
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Caro
authors.forename: Patricia D
authors.initials: PD
authors.lastname: Zubata
authors.forename: Marcela B
authors.initials: MB
authors.lastname: Zubillaga
mesh_terms: 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
chemical_list: D011663:Pulmonary Surfactants; D019275:Radiopharmaceuticals; D013667:Technetium