Application of Electrochemically Reduced Water for New No-Rinse Shampoo: Design and Optimization Using Response Surface Methodology

Abstract

Coronavirus disease (COVID-19) cases are continuing to rise around the world, with more than 607 million confirmed cases and more than 6.51 million deaths as of September 2022. The World Health Organization (WHO) has emphasized the importance of hygiene in the ongoing COVID-19 pandemic, especially in elderly and bedridden patients. The use of no-rinse shampoo represents a simple change in hair-cleansing products. Daily hospital hair washing for the elderly, bedridden, and ICU patients would be more readily adopted. The objective of this study was to design and optimize a new no-rinse shampoo based on electrochemically reduced water (ERW) using response surface methodology. The relationship between coconut-based surfactant mixtures in a no-rinse shampoo and the resulting physicochemical properties, effectiveness (antibacterial and antifungal activity), and stability of the shampoo was investigated. The vesicle size, size distribution, zeta potential, conductivity, pH, foamability, wetting time, turbidity, and stability of the model formulation were optimized. The optimal formulation with the appropriate physicochemical properties and stability was selected. The effectiveness of the optimal formulation was compared to that of commercially available products. The dry shampoo (DS4) containing 3.5% of the mixed detergent with ERW may prevent infection by Escherichia coli, Staphylococcus epidermidis, Staphylococcus aureus, and Candida albicans. The no-rinse shampoo based on ERW successfully demonstrated good stability in addition to efficacy in terms of antibacterial and antifungal activity. The treated hair fiber was not significantly different from that of the intact hair fiber. Under the scanning electron microscopy (SEM) and the atomic force microscopy (AFM), the cuticle layer of the treated hair fiber was not damaged. Thus, no-rinse shampoos may reduce the time of hair rinsing and improve the quality of life of caregivers.