Stability of Epinephrine in a Normal Saline Solution
Dilution of concentrated epinephrine prior to intravenous use during clinical emergencies can delay urgent interventions. The objective of this study was to determine whether diluted epinephrine remains stable and sterile over time in common hospital settings. Epinephrine samples were prepared by clinically relevant double dilution techniques. Samples were stored in 10-mL syringes and incubated under 1 of 4 simulated hospital environments with a mixture of lighting and temperature settings: 4°C/20°C, with or without fluorescent lighting. Samples were incubated for 0, 15, 30, 60, or 90 days. Capillary zonal electrophoresis was used to quantify the concentration of epinephrine and/or presence of any degradation products. All samples were tested for the presence of bacterial growth using blood agar cultures. Diluted epinephrine samples remained stable for up to 90 days in all 4 simulated clinical storage conditions. No bacterial colony-forming units were detected in any of the environmental samples regardless of incubation duration, light, or temperature conditions. Diluted epinephrine for anticipated clinical emergencies may remain clinically useful for up to 90 days, thus improving patient safety, access to medications, and overhead costs by reducing waste.Objective
Methods
Results
Conclusion
CZE Concentration Response Curve
Representative concentration-response curve for CZE analysis of epinephrine. Epinephrine levels were quantified using diode array detection (DAD) at a wavelength of 205 nm. A stock solution of epinephrine was used to generate an 8-point standard curve, and the results of this concentration curve are shown here. Linearity of response, which is critical for quantification of epinephrine in solution, was demonstrated to be achievable across the range of epinephrine concentrations encountered in this study. The best-fit line for the standard curve shown here had an r2 value of 0.9962, indicating a high degree of linearity and a strong correlation between concentration and absorbance unit response (peak area) across the concentrations of epinephrine used in subsequent experiments. The limit of detection (LOD) for epinephrine solutions used in this study was 1 µg/mL, and the maximum concentration on the standard curve was 50 µg/mL.
Epinephrine Concentration Between 0 and 30 Days
The relatively uniform concentrations of epinephrine observed in samples across all day, light, and temperature treatments indicate that little or no degradation of epinephrine occurred in samples, regardless of the storage conditions. Bars represent average ± SD.
Epinephrine Concentration Between 0 and 90 Days
The relatively uniform concentrations of epinephrine observed in samples across all day, light, and temperature treatments indicate that little or no degradation of epinephrine occurred in samples, regardless of the storage conditions. Bars represent average ± SD.
Sterility Testing
Colony-forming units (CFUs) represent contamination as a function of the number of microbial cells present in the indicated samples. Samples 1 to 60 and the negative control sample did not show evidence of contamination (n.d. = no difference) due to absence of microbial cells. Positive controls showed evidence of contamination as expected.
Contributor Notes