a dermatological view
a protective gel following exposure to
acetone and kerosene. Unprotected skin
showed cell damage and a disorganized
pattern in the upper layers of epidermis.
However, skin treated with the protective agent showed substantially reduced
ultrastructural and relief changes of epidermis cells when exposed to solvent.
Bioengineering evaluation of BCs:
Grunewald et al. evaluated BC protective effects using bioengineering
techniques and a sodium lauryl sulfate
(SLS) repetitive washing model on 15
human volunteers. All BCs reduced
the deterioration of skin functions
after one week of repetitive washing.
Subsequently, researchers also found
that urea and glycerol o/w emulsions
provided greater protection than three
commercial BCs when tested against
the lipophilic irritant toluene after seven
days of repetitive irritation.
The effectiveness of BCs was measured on human subjects against dye
indicator solutions including methylene
blue in water and oil red O in ethanol,
where methylene blue was representative
of model hydrophilic compounds and
oil red O was representative of lipophilic
compounds. Each solution was applied
at 5% to untreated and BC-pretreated
skin with the aid of aluminum occlusive
table 1. common terms and definitions relating to Skin Protection
term definition
Occupational
skin protection
chambers for 0 hr and 4 hr. Post application time, materials were removed
and consecutive skin surface biopsies
(SSBs) were obtained. The amount of
dye penetrating into each strip was
determined colorimetrically. Two model
creams exhibited protective efficacy but
one enhanced the cumulated amount of
dye—i.e., it failed to exhibit protective
effect against dye indicators.
Four BCs vs. four irritants: Schlüter-Wigger and Elsner compared four
commercially available BCs with four
standard irritants: 10% SLS, 1% sodium
hydroxide (NaOH), 30% lactic acid (LA)
and undiluted toluene in a repetitive
irritation test (RIT) on humans for
12 days. Irritation was assessed by visual
scoring, transepidermal water loss
(TEWL) measurements and colorimetry. All products were effective against
SLS irritation. Nevertheless, no BC
provided significant protection against
toluene. Three of the four products
tested showed a partially protective
effect against all ionic irritants, while the
fourth showed less protection against
SLS and NaOH, and even amplification
of inflammation by toluene.
Petrolatum skin protection:
Wigger-Alberti and Elsner evaluated the
protective effects of petrolatum utilizing
the same model and noted that petrolatum was effective against SLS, NaOH and
LA irritation; it also provided moderate
protection against toluene. Subsequently,
the researchers examined the efficacy of
Occupational
dermatologic product
table 2. Skin Protectants
identified by the Fda and
their concentrations
Skin protection products
Skin conditioning
Skin regeneration
ingredients concentrations (% w/w)
Allantoin 0.5–2.0
Aluminum hydroxide gel 0.15–5.0
Calamine 1.0–25.0
Cocoa butter 50.0–100
Dimethicone 1.0–30.0
Glycerin 20.0–45.0
Kaolin 4.0–20.0
Petrolatum 30.0–100
Shark liver oil 3.0
White petrolatum 30.0–100
Zinc acetate 0.1–2.0
Zinc carbonate 0.2–2.0
Zinc oxide 1.0–25.0
158 | Cosmetics & Toiletries® magazine www.CosmeticsandToiletries.com
Vol. 126, No. 3/March 2011
