Background and importance Atreonam is an antibiotic used to treat severe infections, such as in intensive care units (ICUs). The dose of aztreonam can vary from 2 to 8 g/day. In ICUs, continuous administration is the preferred mode of administration and a minimum volume is used for patients requiring fluid restriction, leading to high concentrations of aztreonam.

Aim and objectives The objective of the study was to assess the stability of aztreonam solutions at 125 mg/mL, diluted in 0.9% sodium chloride (NS) or 5% glucose (D5W), in polypropylene syringes not protected from light, after preparation, and after storage for 6, 24 and 48 hours at 20–25°C.

Material and methods Three syringes for each condition were prepared. For each analysis, three samples from each syringe were analysed by high performance liquid chromatography (HPLC) coupled with a photodiode array detector at 270 nm. The method was validated according to the International Conference on Harmonisation Q2 (R1). The stability indicating capability was evaluated by analysing forced degraded pemetrexed solutions. Physical stability was evaluated by visual and subvisual inspection (turbidimetry). pH values were measured.

Results Three syringes for each condition were prepared. For each analysis, three samples from each syringe were analysed by HPLC coupled with a photodiode array detector at 270 nm. The method was validated according to the International Conference on Harmonisation Q2 (R1). The stability indicating capability was evaluated by analysing forced degraded pemetrexed solutions. Physical stability was evaluated by visual and subvisual inspection (turbidimetry). pH values were measured.

Conclusion and relevance Aztreonam 125 mg/mL at room temperature not protected from light in D5W or NS in polypropylene syringes was stable for 24 hours. These stability data of highly concentrated solutions provide additional knowledge to assist ICUs in their daily practice. Highly concentrated aztreonam solutions are stable after a 24 hours of storage and can be administered as a daily infusion.

References and/or acknowledgements No conflict of interest.