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


OBJECTIVE
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.


CONCLUSIONS
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.
Rawas-Qalaji
Mutasem
M
College of Pharmacy, Nova Southeastern University, Fort Lauderdale, Florida, USA.
Simons
F Estelle R
FE
Collins
David
D
Simons
Keith J
KJ
D000322:Adrenergic Agonists / Q000008:administration & dosage* / Q000737:chemistry*; D000707:Anaphylaxis / Q000188:drug therapy*; D004355:Drug Stability; D004356:Drug Storage; D004837:Epinephrine / Q000008:administration & dosage* / Q000737:chemistry*; D005392:First Aid; D006358:Hot Temperature; D006801:Humans; D006813:Humidity; D008027:Light; D012996:Solutions; D013594:Syringes; D013997:Time Factors
D000322:Adrenergic Agonists; D012996:Solutions; D004837:Epinephrine