Stability of vincristine (Teva) in original vials after re-use, and in dilute infusions in polyolefin bags and in polypropylene syringes

Study objectives: To establish the stability of vincristine (Teva) in original vials with re-piercing over 28 days, and the stability of dilute infusions in polyolefin containers and polypropylene syringes at drug concentrations/storage condition combinations of relevance to ‘standard’ pharmaceutical practice that meet UK Department of Health National Patient Safety Agency guidance.Methods: Original vials of vincristine injection (5 mg/5 mL, Teva) were stored under different conditions and subjected to re-piercing at intervals over 28 days. Samples taken at each interval were subjected to a stability-indicating LC assay for vincristine. In separate studies, the stability of vincristine infusions (50 mL) in polyolefin bags (0.01 and 0.05 mg/mL) and in polypropylene syringes (0.5 mg in 20 mL and 2 mg in 20 mL), was determined under refrigerated and room temperature conditions.Results: Vincristine injection (5 mg/5 mL) in original vials was chemically stable (> 95% of initial concentration remaining) when stored at refrigerated or room temperature, with and without light protection, and subjected to six piercings of the vial over 28 days. The very dilute 0.01 mg/mL vincristine infusions in polyolefin containers exhibited unpredictable chemical stability, although no infusion fell below 90% of initial concentration remaining over 84 days. The 0.05 mg/mL infusion in polyolefin containers and the 0.5 mg/20 mL and 2 mg/20 mL infusions in polypropylene syringes were all physically and chemically stable over 84 days under both refrigerated and room temperature storage.Conclusion: Vials of vincristine injection (Teva) which are subject to repeat piercing, may be stored for up to 28 days with no loss of chemical potency. Vincristine infusions (0.05 mg/mL in polyolefin bags and either 0.5 or 2.0 mg/mL in 20 mL in polypropylene syringes) were physically and chemically stable for up to 84 days. Infusions of 0.01 mg/mL in polyolefin bags exhibited unpredictable drug assay values and cannot be considered stable. Microbiological considerations were not part of this study and must be established by individual compounding units.