Stability of a heparin-free 50% ethanol lock solution for central venous catheters

Objectives. To determine the stability of a compounded 50% ethanol solution (v/v) in syringes used for ethanol locks for central venous catheters. Design. Syringes were compounded with 50% ethanol solution (v/v) and were tested for ethanol concentration over a 28 day period. Syringes were stored at room temperature not protected from light and assayed on days 0, 1, 2, 3, 6, 7, 10, 15, 17, 21, and 28. Ethanolic content was determined using gas chromatography/flame ionization detection (GC/FID) Varian CP-WAX58 (FFAP) CB capillary column. Setting. University of Wisconsin Comprehensive Cancer Center. Results. The Mean value for all samples over 28 days was found to be 47.08% with a standard deviation of 2.72. Mean ethanol concentrations ranged from 43 to 52% over the 28 day period and did not vary with time. Conclusions. Ethanol is an effective disinfectant against a broad range of micro-organisms, including bacteria and fungi. Retrospective trials have sugguested that the efficacy of an ethanol lock solution is superior to systemic antibiotics to treat and/or prevent central line venous infections; however, there is not a commercially available pharmaceutical product and ethanol 50% solutions are currently compounded. These findings suggest that a 50% (v/v) ethanol solution stored in a syringe at room temperature, not protected from light is stable over a 28 day period.