Purpose Bortezomib (Velcade) is an antineoplastic drug widely used in the treatment of multiple myeloma. According to the manufacturer, once reconstituted, bortezomib is only stable for 8 h at 25 °C. The aim of this study was to evaluate the stability of reconstituted bortezomib stored in original vials and syringes at 4 °C and 28 °C, for up to 10 days.

Methods Samples were prepared by dissolving 3·5 mg of bortezomib powder in 3·5 ml of physiological saline (final concentration 1 mg/ml) under routine clinical conditions. Samples were stored in vials or syringes at 4 °C and 28 °C with photoprotection, and drug stability was analysed by high performance liquid chromatography.

Results Bortezomib was stable in both original vials and syringes for up to 10 days at 4 °C with photoprotection. Furthermore, it was stable for up to 8 days at 28 °C in original vials with photoprotection.

Conclusions Our results showed an extended stability of bortezomib prepared under routine clinical conditions and stored at 4 °C, which could make an important contribution towards reducing drug waste and, consequently, improving cost efficiency.