Stability of nitroglycerin solutions in polyolefin and glass containers

The stability of nitroglycerin in concentrations of 200 and 400 micrograms/ml in eight common intravenous solutions was studied. Two containers of each solution at each concentration, one glass and one polyolefin, were stored under each of the following conditions: intense light (1400-2000 foot-candles) and ambient room temperature (18-27 degrees C), normal light and ambient room temperature, dark and 40 degrees C, and dark and 5 degrees C. All samples were tested at 0 and 24 hours. Room temperature and refrigerated samples were also tested at 48 hours, 7 days, and 1 month. Testing included measurement for optical density at 400 and 600 nm, pH, and nitroglycerin content as determined by HPLC. The admixtures remained clear and colorless, and no appreciable changes in pH were observed. HPLC assays showed no significant changes in nitroglycerin concentrations. There were no differences in the stability of the admixtures stored in the glass and polyolefin containers. Nitroglycerin is compatible with each of the common intravenous solutions tested under the storage conditions and in the containers used for this study.