title: Volatility of radiopharmacy-prepared sodium iodide-131 capsules.
abstract: OBJECTIVE
  The aims of this study were to quantify the extent of volatilization from 131I-NaI therapeutic capsules prepared in a centralized radiopharmacy and to quantify the amount of volatile 131I released from a dispensing vial containing a compounded 131I-NaI therapy capsule.
  
  
  METHODS
  Therapy capsules were prepared by injecting 131I oral solution into capsules containing anhydrous dibasic sodium phosphate. Volatilized activity was obtained by filtering air drawn across samples that were placed open on the bottom of a sample holder cup. Volatile 131I was captured by filtering it through 3 triethylenediamine-impregnated carbon cartridge filters, arranged in series. To quantify the amount of volatile 131I released from a dispensing vial during a simulated patient administration, a vial containing a compounded 131I therapy capsule was opened inside a collapsible plastic bag and all the air was drawn across TEDA-impregnated carbon cartridge filters.
  
  
  RESULTS
  The 370-MBq (10-mCi) 131I capsules from the first part of the experiment released an average of 0.035% (SD 0.031%) of the capsule activity on the first day, 0.012% (SD 0.002%) on the second day, and 0.012% (SD < 0.001%) for days 3 through 5. The 37-MBq (1-mCi) 131I capsules released an average of 0.058% (SD 0.025%) on the first day, 0.029% (SD 0.009%) on the second day, and 0.020% (SD 0.004%) on the third day. The activity released from the vial during a simulated patient administration was 0.00093% of the 131I capsule activity.
  
  
  CONCLUSIONS
  The amount of 131I, which volatilized daily from the exposed therapy capsules, was a small percentage of the capsule activity. The volatile 131I that would be released during a patient administration was much less than the activity that volatilized from the exposed therapy capsules.
authors.affiliation: Pharmacy Services, Syncor International Corporation, Albuquerque, New Mexico, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Bright
authors.forename: T T
authors.initials: TT
authors.lastname: Rees
authors.forename: L E
authors.initials: LE
authors.lastname: Baca
authors.forename: R L
authors.initials: RL
authors.lastname: Green
mesh_terms: D006801:Humans; D007457:Iodine Radioisotopes / Q000737:chemistry*; D011835:Radiation Protection; D019275:Radiopharmaceuticals; D012974:Sodium Iodide / Q000737:chemistry*; D014835:Volatilization
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D012974:Sodium Iodide