Preparing a Diluted Aseptic Solution of Benzalkonium Chloride Using Commercially Available Plastic Bottles of Sterile Distilled Water for Injections

Abstract

We developed a new method for preparing a diluted aseptic solutipn of benzalkonium chloride (BAC) using a commercially available plastic bottle of sterile distilled water for injection. A rubber patch was attached to the shoulder of the plastic bottle immediately after the sterilization had been done using 70% ethanol. A solution containing 10% BAC filtered through a membrane with a mean pore size of 0.22μm was injected into the plastic bottle through the rubber patch: In order to assess the aseptic lezel of the solution prepared according to this method, we aseptically filled the bottle with two culture media consisting of soybean casein digest broth (n=20) or glucose peptone broth (n=20). Tap water was also injected into the bottle according to the procedure. Each of these resulted in a negative bacterial contamination. No change was observed in the BAC contents, pH values and bactericidal activities against five strains (S. aureus, E. coli, P. aeruginosa, S. marcescens, and F. meningosepticum) of the BAC solutions (0.02% and 0.1%) tested during the storage period of six months at room temperature. The time required for preparing a solution by this method was about one-fifth of that according by the preestablished method where a grass bottle containing a diluted disinfectant solution was sterilized using an autoclave.