Long-Term Stability Comparison between an Original and a Generic Version of Piperacillin/Tazobactam in Dextrose 5 % Infusion Polyolefin Bags at 5 ± 3 °C after Microwave Freeze-Thaw Treatment

Abstract Background Piperacillin-Tazobactam is frequently infused in hospitals. The use of a generic version was considered after the out of stock of the brand name Tazocin®. The stability of 4 g of Tazocin® in 120 mL of dextrose 5 % (D5) was demonstrated during 35 days at 5 °C ± 3 °C after freezing (−20 °C) and microwave thawing (FMT). The aim of the study was to investigate and compare the long-term stability of Tazocin® and a generic product in the same conditions. Methods Five polyolefin bags of 4 g of Piperacillin/Tazobactam® Sandoz and 5 bags of 4 g of Tazocin® were prepared under aseptic conditions in 120 mL of D5 and stored 3 months at 20 °C then thawed and stored 58 days at 5 ± 3 °C. Spectrophotometric absorbance at different wavelengths, pH measurement, visual and microscopic observations were also performed. The concentrations were measured by HPLC, at 211 nm for tazobactam and 230 nm for piperacilline. Results No significant change in pH values or optic densities, no crystals were detected. The lower confidence limit at 95 % of the concentration for the solutions remains superior to 90 % of the initial concentration until 58 days of storage at 5 ± 3 °C. Conclusion Under these conditions, 4 g/120 mL of Piperacillin/Tazobactam® Sandoz or Tazocin® in D5 infusion in polyolefin bags remains stable at least for 58 days at 5 ± 3 °C after FMT