Long-term stability of 5-Fluorouracil in 0.9% sodium chloride after freezing, microwave thawing, and refrigeration.

OBJECTIVE To investigate the stability of 5-fluorouracil diluted in 0.9% sodium chloride (normal saline [NS]) after freezing, microwave thawing, and storage for 28 days at 5°C ± 3°C. METHODS Polyvinylchloride (PVC) infusion bags (n = 5) containing 5-fluorouracil 800 mg/100 mL were frozen for 79 days at -20°C. The bags were then thawed in a microwave oven and stored at 5°C ± 3°C for 28 days. The concentration of 5-fluorouracil was measured by high-performance liquid chromatography. Visual and microscopic inspections were performed and pH was measured periodically during storage. Solutions were considered stable if the lower limit of the 95% confidence interval of the concentration versus time profile remained greater than 90% of the initial concentration. RESULTS No colour change or precipitation was observed in any of the solutions. Slight changes in pH were observed during refrigeration. 5-Fluorouracil solutions were stable during storage at 5°C ± 3°C for 28 days, as indicated by the results of high-performance liquid chromatography. CONCLUSION 5-Fluorouracil 8 mg/mL in NS may be prepared in advance, frozen and stored in PVC bags, and thawed before use. The solutions remained stable after freezing at -20°C for 79 days followed by storage at 5°C ± 3°C for up to 28 days.