Stability of epinephrine at standard concentrations.

BACKGROUND

To minimize medication errors, standard concentrations are recommended for medications intended for continuous infusion in pediatric patients. Premixing of epinephrine (commonly used to manage septic shock in children) would improve timeliness, safety, and cost-effectiveness. However, information about the stability of epinephrine at standard concentrations is limited.

OBJECTIVES

To evaluate the stability of epinephrine in 5% dextrose in water at standard concentrations and to extend its expiration date after storage in infusion bags at 4°C and 25°C for up to 30 days.

METHODS

A total of 6 infusion bags were prepared with 200 mL of epinephrine solution, 2 bags for each of 3 standard concentrations (25, 50, and 100 μg/mL). Three bags (one for each concentration) were stored under refrigeration (4°C), and the remaining 3 bags were stored at room temperature (25°C). Physical characteristics (including pH, colour, and presence of precipitate) were evaluated daily for the first 14 days and every 1 to 5 days thereafter until day 30. Three 1.5-mL samples were collected from each bag immediately after preparation (time 0), every 24 h (at 24 h, 48 h, 72 h, 96 h, etc.) for the first 14 days, and every 1 to 5 days thereafter until day 30. Each sample was analyzed by stability-indicating high-performance liquid chromatography. A solution was considered stable if it maintained at least 90% of its initial concentration.

RESULTS

No notable changes in pH, colour, or precipitation were observed in any of the solutions after storage at 4°C or 25°C for up to 30 days. All formulations maintained more than 95% of the initial epinephrine concentration on day 30. In addition, the calculated lower limit of the 95% confidence interval indicated that 93% or more of the initial concentration remained on day 30.

CONCLUSIONS

Preparations of epinephrine were stable for up to 30 days, with or without refrigeration. Because stability alone does not guarantee bioavailability or efficacy of a drug, future clinical studies are recommended to evaluate the pharmacokinetics and pharmacodynamics of these formulations.