The Challenges of formulating a hand sanitizer
With the onset of the COVID-19 pandemic hand sanitizers exploded in popularity. Sales increases of over 250% year-over-year have been reported in the UK (1) and the market is predicted to grow much more in the coming years. Even on the cosmetic science forum (2) discussions about formulating hand sanitizers dominated the early part of the year. While hand sanitizers are not technically considered cosmetics in the US (they are classified as OTC drugs), the job of creating these formulas typically falls on the cosmetic chemist. Let’s look at these products and some of the most significant challenges faced when creating a hand sanitizer in the midst of a pandemic.
WHAT ARE HAND SANITIZERS?
Hand sanitizers are simple formulas with just a few ingredients. For the most basic formulas, The World Health Organization (WHO) has published a pamphlet (3) listing formulas that contain
- Water – solvent
- Alcohol – (either Ethanol or Isopropyl Alcohol)
- Hydrogen Peroxide
The hydrogen peroxide is used in cases when you are starting with water of questionable quality and is not absolutely necessary.
The glycerol is a humectant which can offset the drying feeling that comes from using the product.
While the WHO formula works well for countries throughout the world, consumers in more developed countries like the US expect more sophisticated products. In addition to the ingredients mentioned, most hand sanitizers are thickened to be gels and have color and fragrance added to make them more appealing. The main thickener is an acrylic polymer like Carbomer which is often neutralized with Triethanolamine.
Some formulas also contain additional moisturizing ing ...