Stability of Omeprazole Sodium and Pantoprazole Sodium Diluted for Intravenous Infusion

Background: Proton-pump inhibitors are often administered by intravenous infusion to raise intragastric pH and prevent rebleeding following endoscopic treatment of bleeding ulcers. Currently, the manufacturers of omeprazole and pantoprazole injections recommend that infusions prepared by dilution in NaCI 0.9% should be used within 12 or 3 hours, respectively. Administration at the ward level would be facilitated if these drugs were known to be stable for up to 24 hours. Objective: To determine whether omeprazole and pantoprazole diluted for infusion in NaCl 0.9% or dextrose 5% are sufficiently stable to allow preparation of 24 hour infusion bags. Methods: Intravenous 500 mL bags of NaCl 0.9% or dextrose 5% containing 200 mg of either omeprazole or pantoprazole were prepared. While stored at 22 °C, samples were withdrawn at intervals up to 10 days, and pH and drug content were measured. ANOVA was used to compare drug concentrations at preparation with those after storage. Results: The pH of the infusions did not alter by more than 0.2 units over 48 hours, but decreased subsequently. The measured concentrations of both omeprazole and pantoprazole decreased during storage. The decrease in concentration was greater in dextrose 5% than in NaCl 0.9% and was related to storage time. However, for both drugs, the mean decrease did not exceed 6% over the first 48 hours. Conclusions: Infusions of omeprazole or pantoprazole can be maintained for up to 48 hours without significant loss of active drug content. Maintaining the same bag for 48 hours may provide cost savings compared with the present practice of replacing bags more frequently.