Effect of Lowering the pH of Sodium Hypochlorite on Control of Pseudomonas aeruginosa in Maintenance of Pharmaceutical Water System

Abstract

Drinking water or potable water is a common source for generation of purified water or demineralized water which is used for processing of medicinal products such as tablets, capsules, syrups, and nasal sprays. Before allowing for purification, it is manufacturer’s responsibility to ensure the microbial load control in the source water to get good quality product water and to avoid biofilm formation in waterlines. The current research involves the study of an effectiveness of sodium hypochlorite (NaOCl) at various concentrations of water pH on microbial control by following pour plate technique. The aim of this study was to examine the effect of lowering the pH on the recovery of Pseudomonas aeruginosa. Three groups were tested by challenging known population of P. aeruginosa by varying the pH of 5.0, 7.0 and 9.0. No significant difference was observed at pH 5.0 and 7.0 and the recovery increased when the pH increased at 9.0. Effective microbial control was obtained at neutral pH. The increase of pH resulted decrease of effectiveness of NaOCl.