Stability of Bendamustine Solutions: Influence of Sodium Chloride Concentration, Temperature and Container

Abstract Background Bendamustine is used for the treatment of non-Hodgkin lymphoma, chronic lymphocytic leukaemia and myeloma. The stability of bendamustine is highly dependent on temperature and chloride-ion concentration. Limited stability data are available. The objective of this work was to study the stability of the bendamustine reconstituted solution at 2.5 mg/mL and the diluted solution in normal saline and 1.5 % sodium chloride to evaluate a potential increase in stability. Methods A stability indicating High Performance Liquid Chromatography method with Diode Array Detection was used. A first study was carried out in glass vials and then in polyolefin containers at 0.25 and 0.60 mg/mL. Solutions were stored at room temperature and at 2–8 °C for 7 days. Results Stability was defined as a concentration above 95 % of the initial concentration [10]. The reconstituted solution at 2.5 mg/mL was stable for only 2 hours at room temperature and 8 hours at 2–8 °C. The stability of diluted solutions was in accordance with the manufacturer’s recommendations of 3.5 hours at room temperature and 48 hours at 2–8 °C. The addition of sodium chloride doesn’t increase the stability for preparation in infusion in daily practice. Conclusions The information brought by this study is an 8-hour stability of the reconstituted solution at 2–8 °C.