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A number of skin-care ingredients have been widely
used in the cosmetic and skin-care industry for many
years. When considering the efficacy of these products,
health-care professionals should look for quantitative
measures detailing the results these additives provide.
Test data should be available that specifically demonstrates
the benefit of the product in actual or simulated
clinical use conditions.
Aloe
Since aloe was included in the first United States
Pharmacopoeia in 1820, many investigators have studied
its efficacy in a wide range of clinical applications.
Various clinical studies have shown that aloe has a role
in the treatment of radiation dermatitis, superficial skin
abrasions, corneal ulcerations, frostbite, burns and leg
ulcers. However, topical aloe is not always a healing and
soothing agent and has been reported to cause both
contact irritation and allergic reactions. It has been
shown that aloe vera gel is only a fair humectant.viii
Additionally, quite a bit of information on aloe's
properties is derived from anecdotes or poorly designed
studies. Often, researchers have worked with crude,
impure extracts of aloe plants that do not necessarily
belong to a single species. The chemical composition
of aloe differs depending upon the species used, and
the time of year the plants are harvested.
The result of this nonuniformity of collection or extraction
process is a wide difference between the contents,
consistency and appearance of one manufacturer's
aloe compared with another. Examples of consumer
products containing aloe are Suave® skin therapy lotion
with aloe vera and St. Ives® advanced therapy lotion
with aloe. The Aloe Corporation also produces many
products in various dosage forms that contain
efficacious amounts of aloe.
Glycerin
Glycerin is one of the best natural moisturizers in living
systems. It is found in a diverse range of living organisms
to maintain the correct osmotic pressure within
living cells. Glycerin has been used in skin-care products
for preventing and treating skin dryness because it
moisturizes and plasticizes the stratum corneum.
Glycerin (also called glycerine and glycerol) is a key
component found in many skin products and has been
used as an effective moisturizer and humectant in
cosmetic products for more than 50 years. Recent
studies have shown that the moisturizing benefits
of glycerin include attraction of moisture and normalization
of desquamation (skin shedding).ix,x,xi
Some examples of skin-care products which contain
efficacious amounts of glycerin are Oil of Olay® cream,
Suave® lotion, Ponds® moisturizing lotion, Neutrogena®
Norwegian formula cream, Vaseline® intensive care
lotion, Curel® lotion, Dermalogica's skin hydrating
booster and many others.
| Therapeutic ingredients' historical irritation potential |
| |
Minimal/Low |
Moderate |
| Aloe xiii |
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| Chitosan xii, xiii |
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| Glycerin ix |
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| Gluconolactone x |
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| Provitamin B5 xv, xviii |
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| Vitamin C xvi |
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| Vitamin E9 |
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| Therapeutic ingredients' historical irritation potential |
Ingredient actions
and benefits |
Glycerol |
Gluconolactone |
Sorbitol |
Citric acid |
Chitosan |
Panthenol/
Provitamin B-5 |
| Add moisture to the skin |
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| Form a protective barrier (film) |
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Inhibit inflammation
(reduce irritation and redness) |
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| Promote wound healing |
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| Inhibit growth of skin bacteria |
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| Decrease appearance of fine lines/wrinkles |
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| Improve skin integrity (barrier function) |
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| Reduce roughness (increase smoothness of skin) |
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| Improve skin texture |
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| Improve skin appearance |
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| Increase elasticity |
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| Improve the integrity of the barrier |
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| Condition/nourish the skin |
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| Strengthens skin tone |
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| Maintains appropriate pH |
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Citric Acid
Citric acid is found on the label of many skin-care, bath and shampoo
products. It is mainly there as a pH adjuster to maintain the appropriate
balance of acidity and alkalinity on the skin. Those skin-care products
that contain extracts of fruits will have citric acid in them along
with the more powerful alpha hydroxy acids (AHA), such as glycolic
and lactic acid.
Sorbitol
Sorbitol is found in a number of oral-care and skincare products.
In skin-care products, it is used as a moisturizer. Examples of
products containing sorbitol are Tom's of Maine® skin care products,
Lubriderm® skin creams, Neutrogena® skin cleansing face bar for
men and Eucerin® original moisturizing lotion.
Gluconolactone
Gluconolactone is an ingredient known to minimize skin flakiness
and is often used for therapy of photodamaged skin. It is an AHA
that has less irritating properties than other AHAs often used in
skin treatments, such as lactic and glycolic acid. The NeoStrata
company has a line of products which contain gluconolactone. Lubriderm®
skin renewal and Exuviance® essential multi-defense day cream are
two other products containing gluconolactone.
Chitosan
Chitosan (or chitin) is a carbohydrate that has the power to bind
to skin and hair and act as a film alone or bind water and other
molecules to be delivered to the skin or hair. It is frequently
used in wound dressings due to its ability to inhibit inflammation
and promote regeneration of injured tissues.xii When chitosan is
included in skin-care products, the skin's ability to retain moisture
increases. xiii,xiv Janssen of Australia has a complete line of
skin-care products containing chitosan, and Neutrogena has a men's
razor defense product on the market that features this ingredient.
Panthenol/Provitamin B-5
Vitamins are not superficial ingredients with just a moisturizing
effect but are actually genuine therapeutic agents.xv,xvi Over the
years, a substantial amount of data has shown that a number of vitamins
can affect the skin when used topically. The effects on the skin
are many and varied, but all of them depend on the absorption of
the vitamins into the epidermis or upper dermis. Studies in recent
years have provided strong evidence that certain vitamins, when
applied topically, can play an important and beneficial role in
the aged skin, particularly panthenol (also known as provitamin
B-5). Products containing panthenol include Morganics skin toner,
Lubriderm® skin renewal, BH California shampoo and conditioner rinse
and Murad® moisture rich cleanser and environment shield protective
hand cream.
References
i Graves, C.J., Edwards, C.and Marks, R.(1995).The effects of protective
occlusive gloves on stratum corneum barrier properties.Contact Dermatitis.
(33),183-187.
ii Zhai, H.and Maibach, H.(2002).Occlusion vs.skin barrier function.
Skin Research and Technology. (8),1-6.
iii Grove, G.L., et al.(2001). Methods for Evaluating Changes in
Skin Condition Due to the Effects of Antimicrobial Hand Cleansers:
Two Studies Comparing a New Waterless Chlorhexidine Gluconate/Ethanol
Emollient Antiseptic Preparation
with a Conventional Water-Applied Product. Am J Infection Control.
(Vol.29,No.6), 361-369.
iv McCormick, R.,B uchman, T., Maki, D.(2000). Double-blind,randomized
trial of scheduled use of a novel barrier cream and an oil-containing
lotion for protecting the hands of health care workers. Am J
Infection Control.(Vol.28,No.6), 302-310.
v Ibid.
vi Loden, M., Maibach, H., Eds.(2000). Dry Skin and Moisturizers:Chemistry
and Function.CRC Press. New York.
vii Boyce, J.M., Pittet, D. (2002).Guideline
for Hand Hygiene in Healthcare Settings: Recommendations of the
Healthcare Infection Control Practices Advisory Committee and the
HICPAC/SHEA/APIC/ IDSA Hand Hygiene Task Force. Infection
Control and Hospital Epidemiology (Vol.23,No.12).
viii http://www.lexli.com/aloevera12.html.
Accessed 1/16/03.
ix Bissett,D., McBride, J. (1984). Skin Conditioning with Glycerol.
J Soc Cosmet Chem.(35), 345-350.
x Shapiro,W., Orth, D., Appa, Y., Contard, P., Rheins, L. (1996,
November) Symposiu of Cosmetic Effiicacy. In Supplement to Cosmetic
Dermatology. 26-30.
xi Rawlings, A., Harding, C., Watkins, A., Banks, J., Ackerman,
C., Sabin, R. (1995). The Effect of Glycerol and Humidity on Desmosome
Degradation in Stratum Corneum. Arch Dermatol Res.(287),
457-464.
xii Ueno, H., Mori, T., Fujinaza, T.(2001). Topical Formulations
and Wound Healing Applications of Chitosan. Adv Drug Deliv Rev.
(Vol.52),105-115.
xiii www.geocities.com/chitosan/cosmetic_en.html.
Accessed 12/27/02.
xiv Chen, R.H., Heh, R.S. (2000). Film Formation Time, Skin Hydration
Effects and Physiochemical Properties of Moisture Masks Containing
Different Water-
Soluable Chitosans. J Cosmet Sci.51(1),1-13.
xv Hickling, M. (1995).Viva Vitamins.Chemist Druggist. 243
(5970), 227-228.
xvi Baschong, W., Hueglin, D., Roeding, J. SOFW Journal.
125(4),18-20.
xvii Zhan, C., Miller, M.R.(2003). Excess length of stay, charges
and mortality attributable to medical injuries during hospitalization.JAMA.(290),1868-74.
xviii D-Panthenol, Roche. http://roche.com/vitamins/pdf/dpanth.pdf
xix West, M. Nourishing your skin.WebMD. Updated May 8,2003. Available
at: http://my.webmd.com/content/article/65/72776.htm.
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