Physicochemical Stability of Aztreonam/Avibactam in Elastomeric Devices for Outpatient Parenteral Antimicrobial...

Outpatient Parenteral Antimicrobial Therapy (OPAT) programs provide a safe and cost-effective strategy for administering intravenous antimicrobials in the home setting. Aztreonam/avibactam (ATM/AVI) is a reserve antibiotic used to treat infections caused by multidrug-resistant Gram-negative bacteria. The aim of this study was to evaluate the physicochemical stability of ATM/AVI in elastomeric pumps for OPAT use.

ATM/AVI was diluted in a 0.9% sodium chloride solution to a concentration of 25/8.33 mg/mL and stored in elastomeric pumps (Infusor LV 10 mL/h, 240 mL; Baxter Healthcare S.A, Zurich, Switzerland). The devices were maintained at 4 °C for 14 days and at 25, 32, and 37 °C for 48 h. Three independent elastomeric devices were prepared for each temperature condition and sampled in duplicate at each time point. Solutions were considered stable if the color, clarity, and pH remained unchanged and if the percentage of intact drug remained ≥90%, as determined via UHPLC-MS/MS.

ATM/AVI in polyisoprene elastomeric devices remained physicochemically stable for up to 14 days under refrigerated conditions and for 48 h at 25 °C, 32 °C, and 37 °C.

ATM/AVI solutions demonstrated prolonged stability under the evaluated conditions, supporting their potential use in OPAT programs via 24 h continuous infusion.