Stability of azasetron-dexamethasone mixture for chemotherapy-induced nausea and vomiting administration.

Combination antiemetic therapy has become common practice for the prevention of nausea and vomiting caused by anticancer drugs. In this study, we investigated the stability of azasetron hydrochloride 0.1 mg/mL plus dexamethasone sodium phosphate 0.05, 0.1, or 0.2 mg/mL in 0.9% sodium chloride injection and stored in polyolefin bags and glass bottles over a period of 14 days at 4°C and 48 hours at 25°C. The stability studies were evaluated by visual inspection, pH measurement, and a high-pressure liquid chromatography assay of drug concentrations. During the study period, the concentration of each drug in the various solutions remained above 97% of the initial concentration at both 4°C and 25°C when protected from room light. Under the condition of 25°C with exposure to room light, the concentrations of both drugs were significantly lowered over 48 hours. The pH value decreased, and the color changed from colorless to pink. Our study demonstrates that the azasetron-dexamethasone mixture at a clinically relevant concentration seems to be stable for 48 hours at 25°C and for 14 days at 4°C when packaged in polyolefin bags or glass bottles and protected from room light. The room light is the main influential factor on stability. Clinicians should be aware that combinations of azasetron hydrochloride and dexamethasone sodium phosphate in solution with light exposure should be avoided.