Today, hand sanitizers formulated with >60% alcohol are more important than ever to kill germs on hands when soap and water are not available. The choice of ingredients for alcohol-based formulations is critical to deliver an efficacious, stable product with pleasing aesthetics. As consumers are increasingly choosing products with ingredients that originate in nature and are based on renewable resources, nature-based rheology modifiers and emollients are valuable for alcohol-based formulations.
In recent studies, cellulose-based thickeners and emollient esters were evaluated in prototype hand sanitizer formulations with 70% ethanol for rheological properties, clarity, electrolyte stability and sensory properties. Formulations tested containing hydroxypropyl methylcellulose (HPMC) and hydroxypropylcellulose (HPC) were compared to acrylate-based formulations. The results show key differences between performance of the formulations with the cellulose-based thickeners showing improved rheology properties in the presences of salt. In consumer tests, the differences in sensory were also noted. For example, panelists noted better moisturization and spreadability with HPC and HPMC. Thus, the choice of ingredients is an important consideration in formulating hand sanitizers, both for sanitizing performance and for positive sensorial experience.