Perhaps the most persuasive tests involve applying prospective
products on volunteers and noting the results, both visibly and
tactically over several weeks. Ideally, the treated dry skin should
lose its rough texture and flakiness without the skin becoming
irritated, sensitized or otherwise traumatized.
The usual protocol for developing a skin moisturizer can be described as:
a. Review toxicological literature for every ingredient
b. Determine dose response data on all ingredients
c. Survey literature and competitive product data
d. Develop irritation data on the proposed formulation
e. Develop human dry skin data and compare with competitive products
f. Conduct consumer tests, getting feedback
g. Reconnoiter the marketplace for comments
The human skin will vary from “normal” to “sensitive” to “highly sensitive” in terms
of cosmetic intolerance syndrome. About 5% of women have significant subjective
sensory irritation problems. They must be very careful when purchasing soaps and
other cosmetics since many products will cause stinging, redness and other forms of
irritation about an hour after application.
With this in mind, the skin moisturizer formulator is challenged to use only mild
and benign ingredients. A large number of products are generally contraindicated.
Some are listed as follows:
• Fragrances with irritating components, such as aldehydes
• Certain preservatives, such as butyl carbamate
• Propylene glycol, butylene glycol and some other glycols
• Certain natural extracts
• Vitamins
• Sunscreens
• Laureth-9
• Caprilic/caproic triglycerides
• Lactic acid
• Chitin
• Antioxidants
Several are utilized in commercial products, but likely in low concentrations
and with their inclusion supported by human testing on hyper-sensitive dry skin
volunteers.
Packaging
To avoid foaminess, skin moisturizers can be formulated as low yield point gels and packed in BOV
aerosol dispensers. The process involves pressurizing and then sealing the empty dispenser, then filling
the multi-layered bag with the product. After pressure and leakage testing, the spout-type actuator is
attached and cans are packed in cartons for shipment. Product viscosity is important—it prevents the
moisturizer from dripping through the consumer’s fingers, yet allowing it to smooth easily on the skin
of areas to be treated. The dispensers are usually of shaped or straight-wall aluminum, holding about
6–8oz.of product. Spray
See the October 2018 issue of SPRAY for Skin Moisturizers vs. Emollients
36 Spray February 2019
In Germany, Duschdas Spray
& Go Body Lotion from
Unilever comes in Cucumber
& Waterdrops, Honeymelon
& Jasmine and Chocolate &
Coconut. The aluminum can
is from Tubex.