OBJECTIVE: After patent expiry of the bevacizumab originator product, several biosimilars were approved by the European Medicines Agency. In centralised preparation units, product-specific in-use stability data must be considered. Based on the available data, stability information was missing for the concentrate for solution of the bevacizumab biosimilar CT-P16 (Vegzelma, Celltrion) after first opening and prolonged storage. The aim of the study was to investigate the physicochemical stability of CT-P16 25���mg/mL concentrate for solution stored in punctured original glass vials at two different storage temperatures over a 28-day period.
METHODS: Three bevacizumab 25���mg/mL vials (CT-P16) were stored punctured either light protected at 2-8��C or at 25��2��C for 28 days. Samples were withdrawn on day 0, 1, 7, 14, 21, 28 and analysed by size-exclusion chromatography (SE-HPLC), ion-exchange chromatography (IE-HPLC), and dynamic light scattering (DLS). In parallel, pH values were measured and test vials visually inspected for visible particles and colour changes.
RESULTS: After the 28-day storage period, the quantitative SE-HPLC analysis indicated bevacizumab concentrations above 95% of the initial concentration in each test vial. IE-HPLC analysis revealed no signs of instability. DLS measurements showed no significant variation in the mean hydrodynamic diameter and no appearance of small-sized aggregates. The pH values of all samples remained constant, and no visible particles or colour changes were observed.
CONCLUSION: CT-P16 25���mg/mL concentrate was found to be physicochemically stable in the original glass vial after first opening for at least 28 days when stored light protected at 2-8��C or at 25��2��C.
