During this COVID-19 situation, hand sanitizers are designed as better alternatives to hand wash lotions and soaps as they reduce the major microbial load on our hands and skin, and in turn reduce chances of infections and severity. As a long sustained exposure of the viral load is required for transmission from an infected person, it is very important to sanitize our hands. The hands are important to sanitize because they are the primary contact to the outside word and subsequently play important roles in touching the face, eyes, and mouth. Hand sanitizer production is regulated in most countries but the FDA has recently lifted up restrictions and made clear manufacturing guidelines. Thus a new wave of manufacturers and formulators are in process to get down to business of hand sanitizers through legal means.
Formulation of Hand Sanitizers
Under the COVID-19 guidance by FDA, hand sanitizer formulas have been allowed with the intention of increasing hand sanitizer production beyond previously licensed or registered drug manufacturers. The World Health Organization has released step by step guide for maintaining local production of hand sanitizers:
The hand sanitizer manufacturing ingredients:
- Ethanol or Isopropanol
- Hydrogen Peroxide
- Sterile water
Mix them with care and get ready with your COVID-19 hand sanitizers. The proportion of ingredients is also specified in volume %. Be aware of the difference between volume% and weight(know about weight vs. volume%).
Formula 1: Ethanol (volume %)
Ethanol 80%; Glycerin 1.45%; Hydrogen peroxide 0.125%; QS water
Formula 2: Isopropanol (volume %)
Ethanol 75%; Glycerin 1.45%; Hydrogen peroxide 0.125%; QS water
In the formulation, QS stands for the Latin quantum satis(sufficient quantityi.e making up the volume with water).
Important Notes on Hand Sanitizer Manufacturing
- Additional fragrance and glycerin are explicitly not allowed under FDA guidance but glycerin can have skin benefits and fragrances are often used to cover the underlying base odor. But at times, fragrance can result in allergic responses on the skin.
- Thickening polymer are not part of the FDA formula described above, but one can read about the different polymeric options for thickening water/alcohol solution here.
- On an important note, the ethanol must be denatured and not to be consumed.
Mixing your Hand Sanitizer
If one is using a glass vessel to mix hand sanitizers, then passivation is not a concern. However, if one is using a metal vessel or stainless steel vessel, find out about passivation here. The packaging must seal sufficiently and manual pumps are also allowed in the FDA guidance.
Hand sanitizers are likely better for the skin barrier rather than soap washing as they can disrupt the natural structure of the skin. In contrast, the alcohol in hand sanitizers rapidly evaporates and has little impact on the skin barrier after killing the viral load.