Purpose: The results of a study to determine the long-term (up to 14 days) stability of diluted dexmedetomidine kept in polypropylene syringes under typical pharmacy storage conditions are presented.
Methods: Four samples of dexmedetomidine injection diluted to 4 μg/mL in 0.9% sodium chloride were prepared and divided into 25-mL portions for storage in syringes at ambient room temperature (20-25 °C) with light exposure or under refrigeration (5 °C) in darkness. At 24 and 48 hours, the percentage of the initial dexmedetomidine concentration remaining in all samples was assessed via high-performance liquid chromatography with diode-array detection; further stability testing of the refrigerated samples was performed on days 7 and 14. At each time point, the test samples were visually inspected for color, clarity, and signs of formation of particulate matter.
Results: As determined by chromatographic analyses, the samples of diluted dexmedetomidine stored in syringes at room temperature exhibited a loss of drug concentration of <10% over 48 hours; the refrigerated samples exhibited a loss of drug concentration of <5% over 14 days. All of the syringe-stored samples remained clear and colorless on visual inspection for the duration of the study.
Conclusion: Dexmedetomidine diluted to 4 μg/mL in 0.9% sodium chloride injection was stable for at least 48 hours at 20-25 °C and 14 days at 5 °C when stored in polypropylene syringes.