Emerging data suggest that intravenous ascorbic acid (AA) may be beneficial in patients with sepsis. Clinicians require data on stability of diluted AA for safe administration. We evaluated the stability of AA diluted in normal saline (NS) or 5% dextrose in water (D5W) solutions over 14 days at 25 °C and at 4 °C, protected from light, using concentrations of 37 mg/mL and 77 mg/mL (Sandoz) and 40 mg/mL and 92 mg/mL (Mylan). We also assessed stability of a 40 mg/mL solution (Mylan) at 25 °C exposed to light for 75 h. Concentrations were measured using liquid chromatographic separation with ultraviolet light detection on days 0, 0.33, 1, 1.33, 2, 3, 4, 7, 10 and 14. By day 14, solutions at 4 °C retained >97.72% of the initial concentration; at 25 °C, solutions retained >88.02% of the initial concentration, but visual changes were evident after day 2. Multiple linear regression demonstrated that study day and temperature (p < 0.001) but not solution type (p = 0.519), concentration (p = 0.677) or manufacturer (p = 0.808) were associated with the percentage remaining. At 75 h, degradation rates were similar in solutions protected from vs. exposed to light. In conclusion, AA solutions are stable for at least 14 days at 4 °C, with protection from light.
Keywords: administration; ascorbic acid; drug stability; sepsis.