BENZALKONIUM CHLORIDE - A POTENTIAL DISINFECTING IRRIGATION SOLUTION

Objective: To determine the disinfecting properties of benzalkonium ch loride as an irrigation agent. Design: Comparison was made between irr igation of contaminated muscle strips with benzalkonium chloride and n ormal saline (control). Summary of Background Data: Benzalkonium chlor ide is a cationic disinfectant. which has questionable able efficacy i n an organic environment. However, no previous study has attempted to use high volumes of this cationic solution to overcome the neutralizin g effect of organic tissue and thus maintain this-detergent's germicid al properties. Methods: 2.5cm x 0.5cm x 0.5cm pieces of bovine muscle were aseptically cut from the center of freshly harvested beef muscle and incubated with 1.0 x 10(7) colony form in units of bacteria for 15 minutes. The muscle strips were then irrigated with either 100mL, 1L, or 10L of benzalkonium chloride at a 1:2000 concentration in normal s aline. Normal saline was used as the control. The muscle strips were s onicated to remove adherent bacteria; the number of living organisms w as determined by quantitatively culturing the sonicate. Results: In vi tro, benzalkonium chloride was superior to normal saline at disinfecti ng bovine muscle (p less than or equal to 0.001). When 10L of benzalko nium chloride irrigation was used, no living bacteria could be recover ed (p less than or equal to 0.012). Conclusion: In this experimental s etting benzalkonium chloride was an effective disinfection agent, with enhanced activity at large volumes.