Long-term stability of temocillin in dextrose 5% and in sodium chloride 0.9% polyolefin bags at 5±3°C after freeze-thaw treatment

Introduction The aim of this study was to investigate the stability of a mixture of temocillin 20mg/ml in 5% dextrose and in 0.9% sodium chloride polyolefin bags after freezing, microwave thawing and long-term storage at 5±3°C. Methods The stability of ten polyolefin bags containing 20mg/ml of temocillin, five bags in 5% dextrose and five bags in 0.9% sodium chloride, prepared under aseptic conditions was studied after freezing for 1 month at –20°C, thawing in a microwave oven with a validated cycle, and stored at 5±3°C. Over 30 days, temocillin concentrations were measured by high-pressure liquid chromatography. Visual inspections, microscope observation, spectrophotometric measurements and pH measurements were also performed. Results and discussion No precipitation occurred in the preparations but minor colour change was observed. No microaggregate was observed with optical microscopy or revealed by a change of absorbance. Based on a shelf life of 95% residual potency, temocillin infusions were stable at least 11 days in 5% dextrose and 14 days in 0.9% sodium chloride after freezing and microwave thawing (corresponding at the period where 95% lower confidence limit of the concentration-time profile remained superior to 95% of the initial concentration). During this period, the pH values of drug solutions have been observed to decrease without affecting chromatographic parameters. Conclusion Within these limits, temocillin in 5% dextrose and in 0.9% sodium chloride infusions may be prepared and frozen in advance by a centralized intravenous admixture service then thawed before use in clinical units.