Helping Hands
Enhancing alcohol-based sanitizing sprays and alcohol-free
hand sanitizing foams with NMF-inspired ingredients
Due to the resurgence of the SAR-CoV-2 virus and corresponding
COVID-19 disease during the colder months
in the U.S. and Europe, products formulated to sanitize
the hands continue to fill a primary need for frontline health care
providers and doctors battling the virus and caring for critically ill
and potentially vulnerable patients.1,2 In addition, U.S. citizens
are being encouraged to practice numerous preventive measures
such as wearing masks, social distancing and, most importantly,
washing or sanitizing hands.3
The continuous use of aggressive ethyl alcohol and isopropyl
alcohol-based products can strip the skin’s stratum corneum
of key moisture binding molecules that keep the skin moisturized4.
At the mantle pH of the skin, many important molecules
like lactic acid, pyrrolidone carboxylic acid and the like, which
comprise part of the Natural Moisturizing Factor (NMF) of the
skin, become solubilized in the alcohol applied to the skin and
are stripped from the skin’s stratum corneum. To overcome these
effects, most alcohol-based hand sanitizers will also include a
portion of glycerin (glycerol) to help keep the skin moisturized.5
However, it is noted that health care workers who frequently
use hand sanitizers will follow this with applications of hand
moisturizers. This can be problematic as it places additional,
non-sanitizing products on top of the sanitizer that may influence
its efficacy.
Alcohol-free hand sanitizers are also popular as they tend to be
less aggressive to the skin. In many cases, Benzalkonium Chloride
is employed as the active ingredient in foaming hand sanitizers,
which are typically formulated in mild surfactant-based aqueous
systems. The repeated use of the surfactant-based systems, however,
can also lend to the drying and cracking of the skin common
to alcohol-based systems. Similarly, while the surfactants used in
the hand foaming systems are typically mild, they can still strip
essential NMF moisturizing components from the skin.
A very practical way to deliver hand sanitizer is via a spray or
pump and it is common to find such a hand sanitizing product
sold in either an aerosol or pump spray dispenser. We recently
reported on work that examined the benefits of adding Natural
Moisturizing Factor (NMF) type components to alcohol-based
sanitizing sprays.6 We noted that the addition of such unique ingredients
into sprays containing glycerin can further improve the
22 Spray February 2021
hydrating benefits of the products compared to the glycerin alone.
We expanded this work to show that such benefits can also occur
from foaming formulations.
Materials & Methods
The 2-propanol-based hand sanitizing sprays employed the ingredients
and proportions noted in Table 1. BP-BotaniDew NMF is
a product of BotanicalsPlus and is provided as a solution in water
(INCI Name: Water and Citrullus Lanatus Watermelon Fruit
Extract and Chenopodium Quinoa Seed Extract and Urea and
Sucrose and Glycerin and Sodium Lactate and Sodium PCA)
and was used as is.7
Skin hydration studies were conducted using the DermaLab
Combo Corneometer instrument (Cortex Instruments, Hadsund,
Denmark).8 Each site was analyzed eight times for each hydration
measurement and the resulting values were averaged. Statistical
analysis was done using Microsoft Excel and was baseline normalized
and paired.
Alcohol-Based Hand Sanitizing Spray Moisturization Study
Four volunteers were employed for the glycerin-based assays and
five volunteers were employed for the glycereth-26 studies.6 The
individuals involved in the studies were between the ages of 17–60
with Fitzpatrick Type skin III-IV.
Individuals’ hands were marked into
four quadrants as shown in Figure 1.
This allowed for application of the
two active formulations containing
3% and 5% BP-BotaniDew NMF
and a site for the placebo product
to the same hand. The final site was
maintained as an untreated control
site measured at every time point.
Prior to commencing the studies,
each site was analyzed for its moisture
content to obtain a baseline
measurement. When calculating the
statistical analysis of each treatment,
the test values were normalized by
subtracting the baseline measure-
James V. Gruber1,
Venera Stojkoska1
& Jed Riemer1
BotanicalsPlus, Fairfield, NJ
Table 1: Summary of hand sanitizing spray formulations including placebo formulations.
Figure 1: Hand Treatment
Region Markings.