Stability of Flucloxacillin in Elastomeric Infusion Devices

Background Stability of antibiotic infusion solutions must be maintained for home infusion therapy. No published data were available to support extended stability of flucloxacillin infusions during storage and administration via elastomeric infusion devices. Aim To determine the stability of high‐dose flucloxacillin in 10 mL/h elastomeric infusion devices after storage for 6 days at 2–8 °C and then temperatures expected during administration. Method Three infusors were prepared for each arm of the study. Each contained 12 g flucloxacillin diluted to 240 mL with 0.9% sodium chloride. Flucloxacillin concentrations were determined after storage at 2–8 °C for 6 days, 2–8 °C for 6 days and then 31 °C for up to 24 hours, and 2–8 °C for 6 days, 31 °C for 17 hours and then 37 °C for 7 hours. Results Flucloxacillin retained 94% of the initial concentration after 6 days at 2–8 °C and at 31 °C for 24 hours but only 87% when the temperature was raised to 37 °C for 7 hours. Conclusion Flucloxacillin at a nominal concentration of 50 g/L is stable in elastomeric infusion devices at 2–8 °C for 6 days and then at 31 °C for 24 hours.