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 the chances of infections
and severity. As a long sustained exposure to 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 world 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 the 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
·
Glycerin
·
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 quantity i.e making up the volume with water).
Important Notes on 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.
