Physicochemical stability of high-concentration cefuroxime aqueous injection reconstituted by a centralised intravenous additive service.

Objectives: Hospital pharmacies provide centralised intravenous additive services (CIVAS), such as antibiotic reconstitution. The aim of this study was to demonstrate the physicochemical stability of high-concentration cefuroxime sodium in aqueous injections, which is mandatory for the centralised preparation of products with automation.

Methods: The physicochemical stability of three high-concentration injections (1.5 g of cefuroxime sodium in 15 mL, 16 mL and 18 mL of water for injection (WFI)) were studied in two primary packing materials (glass vials and polypropylene syringes). The samples were reconstituted with automation in three mid-sized hospital pharmacies in a good manufacturing practice (GMP) grade A/B cleanroom. During the study, the samples were stored in refrigerated conditions (4°C) and 1.5 g/15 mL solution in ambient temperature (22°C). Cefuroxime and descarbamoyl cefuroxime were analysed by high-performance liquid chromatography with UV detection. In addition, the appearance, pH and uniformity of dosage units were investigated.

Results: The freshly prepared cefuroxime injections fulfilled the criteria of content uniformity (acceptance value (AV) <15). A significant decrease in concentration of cefuroxime and increase in content of descarbamoyl cefuroxime was observed in all injections. Cefuroxime aqueous injections were physiochemically stable for up to 14 days under refrigeration storage. The relative content of descarbamoyl cefuroxime remained under 3% at 4°C. The solution of 1.5 g/15 mL was stable for only 20 hours in formulations stored for the first 14 days at 4°C and then transferred to 22°C. The colour of the solution changed from light yellow to a darker yellow, and the pH value of the solutions increased during storage. Neither primary packing materials, commercial source of cefuroxime sodium nor exposure to light had any significant effect on the stability of formulations.

Conclusions: Although limited, we found the shelf life of high-concentration cefuroxime injections in refrigerated conditions sufficient for centralised antibiotic preparation in hospital pharmacy with automation. The limited shelf life of high-concentration cefuroxime injections must be considered when using these formulations.