Stability of lyophilised oxaliplatin formulation in polyolefin infusion bags containing 5% dextrose injection

Objective The in-use stability of lyophilised oxaliplatin and lactose formulation diluted in 5% dextrose injection was studied to assess the feasibility of preparing oxaliplatin solutions in advance in hospital pharmacy settings. The available in-use stability data of oxaliplatin solutions are based on infusions prepared with 5mg/mL concentrated solutions. Methods Oxaliplatin solutions of 0.5mg/mL (n=6), 0.7mg/mL (n=6) and 5mg/mL (n=6) were prepared using oxaliplatin 100mg powder and 100mL of 5% dextrose injection in polyolefin infusion bags. The samples were stored at 2-8 degrees C without light protection and were analysed at 1, 2, 4, 7, 14, 21 and 60days. The in-use stability was studied using the high-performance liquid chromatography stability indicating method. The solutions were checked for colour, particulate matter and pH. Results The mean concentrations of 0.5mg/mL and 0.7mg/mL oxaliplatin solutions decreased to less than 90%, within 7 and 14days, respectively, compared with the initial drug concentration in the solutions. The concentrated solution of 5mg/mL oxaliplatin was stable (over 90%) for at least 60days. The colour, clarity and pH remained unchanged throughout the storage period. Sterility and apirogenicity standards, as defined in the European Pharmacopoeia, were met. Conclusion Infusion solutions of oxaliplatin prepared with lyophilised oxaliplatin 100mg, 0.5mg/mL and 0.7mg/mL which were stored in polyolefin infusion bags, were chemically unstable within 7days and 14days, respectively, at 2-8 degrees C without light protection. The poor stability of the diluted solutions does not allow oxaliplatin to be prepared in advance and stored in pharmacy departments.