Stability study of sodium hypochlorite for optimizing support routines at Bio-Manguinhos

Introduction:The Section of Serological Panels and Support (SEPPS) plays a key role in supporting the production of diagnostic kits and in the External Quality Assessment.The Support section carries out essential activities such as decontamination, sterilization and solution production.Due to increasing demand, it became crucial to extend the holding time of sodium hypochlorite solutions at 1.0% and 2.5% (v/v) in order to optimize support routines, as the previous storage period was limited to just a day.Objectives: To establish the holding time of 1.0% and 2.5% (v/v) sodium hypochlorite solutions produced by SEPPS and used in cleaning processes at Bio-Manguinhos. Methodology:The concentration evaluation was performed using redox titration method.Solutions of sodium hypochlorite at 1.0% and 2.5% (v/v) were analyzed in three different batches, with volumes of 500 mL (polycarbonate bottles), 1 L (ethylene glycol terephthalate bottles), 10 L and 50 L (polypropylene bottles).The samples were evaluated over 28 days, with analyses conducted on days 0, 7, 14, and 28, stored at room temperature (20 5C).For the analyses, aliquots of at least 30 mL were collected, stored in the same material as the primary packaging of the preparation.Results: The 1.0% (v/v) sodium hypochlorite solution remained within its specification (0.9 to 1.1% v/v) for 28 days at 205C when packaged in 1L polyethylene terephthalate bottles, 10L and 50L polypropylene bottles.Since the 10L and 50L volumes were approved, the 20L volume was also approved.When packaged in 500mL polycarbonate bottles, it remained within specification for 14 days at 205C.For the 2.5% (v/v) sodium hypochlorite solution, the 500mL polycarbonate bottles, 1L polyethylene terephthalate bottles, and 10L and 50L polypropylene bottles were in compliance with the specification (2.0 to 3.0% v/v) for 28 days at 205C. Conclusion:The study established that sodium hypochlorite solutions at 1.0% and 2.5% (v/v) maintain stability for up to 28 days, depending on the type of packaging and volume.These results allow for optimizing usage, reducing the frequency of solution preparation, minimizing costs, and preventing waste, without compromising their efficacy.