Stability of ondansetron stored in polypropylene syringes

OBJECTIVE: To evaluate the stability of ondansetron hydrochloride undiluted and mixed in dextrose 5% injection or NaCl 0.9% injection during storage in polypropylene syringes when frozen, refrigerated, or at room temperature. DESIGN: Batch quantities of ondansetron 0.25, 0.5, 1.0, and 2.0 mg/mL were prepared and individual doses of 10.5 mg were drawn into polypropylene syringes that were stored at -20 degrees C for up to 3 months, at 4 degrees C for up to two weeks, or at 22-25 degrees C for two days, and various combinations of these conditions. At defined sampling times aliquots were withdrawn from syringes, the solution visually inspected, pH measured, and ondansetron concentration determined by HPLC. Drug loss of > or = 10 percent of the original content of the solution was considered clinically significant. RESULTS: The ondansetron concentration in each solution, regardless of storage conditions, remained above 90 percent of the original concentration at each observation time (range 92-107 percent). No changes in color or clarity of any of the solutions were observed, and only slight fluctuations in pH (< or = 0.05) were noted. CONCLUSIONS: Ondansetron 2 mg/mL undiluted, or at concentrations of 0.25, 0.5, or 1 mg/mL, mixed in dextrose 5% injection or NaCl 0.9% injection was determined to be stable when stored in polypropylene syringes for each storage condition at all time points studied, including the maximum for each: three months at -20 degrees C, followed by 14 days at 4 degrees C, and by 48 hours at 22-25 degrees C.