Stability of 70% alcohol solutions in polypropylene syringes for use in ethanol-lock therapy

Purpose. The stability of 70% alcohol solutions in two diluents stored at 23–25 °C over 14 days in two brands of polypropylene syringes was studied. Methods. A 70% alcohol solution was aseptically prepared by adding Dehydrated Alcohol Injection, USP, to Sterile Water for Injection, USP (SWI), in an evacuated i.v. bag. This process was repeated with Bacteriostatic Water for Injection, USP (BWI). Identical 3-mL samples of each of the two solutions were drawn into 10-and 12-mL syringes (each a different brand) and stored at 23–25 °C. The stability of the samples was analyzed with high-performance liquid chromatography immediately after preparation and at 3, 7, and 14 days. Results. At least 96% of the initial concentration of alcohol remained throughout the 14-day study period in all syringes. There were no detectable changes in color or volume and no visible evidence of precipitation or microbial growth in any sample. Conclusion. Extemporaneously prepared 70% alcohol solutions in SWI or BWI were stable for at least 14 days at 23–25 °C in two brands of polypropylene syringes.