Long-term stability of ketamine hydrochloride 50mg/ml injection in 3ml syringes.

INTRODUCTION: Ketamine hydrochloride (Ketalar(®)) injection is often used as a general anesthetic agent. It is particularly suited to short-term interventions. It can also be used as an inducer of anesthesia before the administration of other anesthetic agents. The aim of this study was to evaluate the stability of ketamine hydrochloride in 3ml polypropylene syringes after storage for up to 180days at room temperature.

METHOD: Syringes containing ketamine hydrochloride (50mg/ml) were prepared and stored at room temperature (25°C) for 180days. The concentrations were measured by validated ultra-performance liquid chromatography-diode array detection at 0, 7, 14, 28, 60, 84, 112, 140 and 180days. A degradation test was performed to evaluate the specificity of the analysis. At each time point, the pH, color and visible particles of each solution were also assessed.

RESULTS: Degradation tests proved no interfering peaks with ketamine. All solutions were physically stable during the storage. The lower confidence limit of the concentration for these solutions remains superior to 90% of the initial concentration at this date as recommended by the Food and Drug Administration (FDA) until 180days (100%±2%).

CONCLUSION: Solutions of ketamine (50mg/ml) were chemically stable for 180days in polypropylene syringes with storage at room temperature and could be prepared in advance by a centralized intravenous admixture service.