Long-term stability of epinephrine dispensed in unsealed syringes for the first-aid treatment of anaphylaxis

Ann Allergy Asthma Immunol. 2009 Jun;102(6):500-3. doi: 10.1016/S1081-1206(10)60124-X.


Background: When epinephrine autoinjectors are unavailable or unaffordable, patients at risk for anaphylaxis in the community are sometimes provided with an unsealed syringe containing a premeasured epinephrine dose for use in first-aid treatment of anaphylaxis episodes.

Objectives: To study the stability of epinephrine solution in unsealed syringes under conditions of high ambient temperature, low vs high humidity, and light vs dark.

Methods: Forty unsealed syringes each containing an epinephrine dose of 0.3 mg (as a 1-mg/mL epinephrine solution) were stored at 38 degrees C for 5 months, with 10 syringes at each of 4 different standardized storage conditions: dark and light at low (15%) humidity and dark and light at high (95%) humidity. Duplicate syringes were removed monthly from each storage environment and analyzed for epinephrine content vs control syringes.

Results: The epinephrine dose, expressed as the percentage remaining of the mean control dose, was below compendial limits (90% to 115% of label claim) by 3 months after storage at 38 degrees C and low humidity and by 4 months after storage at 38 degrees C and high humidity. Light had no significant effect.

Conclusion: In hot climates, if an unsealed syringe prefilled with an epinephrine dose is provided for the first-aid treatment of anaphylaxis, it should be replaced every few months on a regular basis with a new syringe containing a fresh dose of epinephrine.

MeSH terms

  • Adrenergic Agonists / administration & dosage*
  • Adrenergic Agonists / chemistry*
  • Anaphylaxis / drug therapy*
  • Drug Stability
  • Drug Storage
  • Epinephrine / administration & dosage*
  • Epinephrine / chemistry*
  • First Aid*
  • Hot Temperature
  • Humans
  • Humidity
  • Light
  • Solutions
  • Syringes
  • Time Factors


  • Adrenergic Agonists
  • Solutions
  • Epinephrine