title: Stability of levothyroxine injection in glass, polyvinyl chloride, and polyolefin containers.
abstract: OBJECTIVE
  The 24-hour stability of a levothyroxine solution admixed and stored in three common infusion containers and infused through polyvinyl chloride (PVC) tubing was evaluated.
  
  
  METHODS
  Levothyroxine sodium 1-μg/mL injection prepared in glass bottles and PVC and polyolefin bags were assayed using high-performance liquid chromatography at 0, 1, 3, 6, 12, and 24 hours; samples drawn directly from the containers, as well as from the distal end of attached PVC tubing, were assayed. The area under the time-versus-concentration curve (AUC) for predicted and delivered doses was calculated; analysis of variance was used for comparison of the percentages of predicted and actual AUC values.
  
  
  RESULTS
  The levothyroxine concentration was stable in glass bottles and polyolefin bags through 24 hours (mean ± S.D. percentage of initial concentration remaining, 103.5% ± 2.5% and 100.0% ± 2.9%, respectively). In the PVC infusion bags, the amount of drug decreased to 90% of the initial concentration within 1 hour and then rose and remained within acceptability limits. The levothyroxine concentration of the samples infused through PVC line from glass and polyolefin containers decreased after 1 hour by about 13%; the loss of the drug from the samples infused from PVC bags was higher (18%), presumably due to additive adsorptive effects. In all samples tested, the drug concentration rebounded and remained above 90% to the end of the study.
  
  
  CONCLUSIONS
  Levothyroxine sodium 1-μg/mL solution was stable for 24 hours in glass bottles and polyolefin bags but when stored in PVC bags, the concentration decreased by 10% after 1 hour.
authors: Department of Pharmacy, Hôpital du Sacré-Coeur de Montréal, Quebec, Canada.
authors: Anne Julie
authors: AJ
authors: Frenette
authors: Robert D
authors: RD
authors: MacLean
authors: David
authors: D
authors: Williamson
authors: Pierre
authors: P
authors: Marsolais
authors: Ronald F
authors: RF
authors: Donnelly
mesh_terms: D000704:Analysis of Variance; D019540:Area Under Curve; D002851:Chromatography, High Pressure Liquid; D004349:Drug Packaging; D004355:Drug Stability; D004356:Drug Storage; D005898:Glass / Q000737:chemistry*; D019999:Pharmaceutical Solutions; D011090:Polyenes / Q000737:chemistry*; D011143:Polyvinyl Chloride / Q000737:chemistry*; D013974:Thyroxine / Q000737:chemistry*; D013997:Time Factors
chemical_list: D019999:Pharmaceutical Solutions; D011090:Polyenes; C035051:PL 732; D011143:Polyvinyl Chloride; D013974:Thyroxine