Skin Biomarkers as objective measures of stratum corneum barrier

SKIN BIOMARKERS AS OBJECTIVE MEASURES OF
STRATUM CORNEUM BARRIER FUNCTION AND
HEALTH FOR FORMULATING PERSONAL CARE
COMPOSITIONS
P2617
Karl Wei, Ching Stella, Ken Wehmeyer, Jeremy Christman, Rolanda Johnson,
Rohan Wimalasena, Tom Huggins and Liza Simms
Beauty and Grooming, The Procter and Gamble Company, USA
Randy Wickett
College of Pharmacy, University of Cincinnati, USA

Introduction
• Xerotic skin is a common skin disorder that is reflected by
reduced stratum corneum hydration, increased transepidermal
water loss, increased proliferation, decreased
differentiation and a loss of skin elasticity. 1-4
• The condition worsens during the dry winter season and
upon repeated usage of harsh personal cleansing
products.
• While moisturizing body wash products are readily
available, few purport to improve skin barrier function and
health beyond traditional moisturization measures.

Objectives
• Develop a set of skin biomarkers as objective measures of
stratum corneum barrier function and health.
• Understand seasonal impact on skin biomarkers (normal
healthy skin vs. xerotic skin).
• Determine the impact of advanced petrolatum-depositing
body wash vs. regular personal cleansing products on skin
biomarkers.

Biomarkers Indicative of Stratum Corneum Health
Stratum Corneum
Quality & Health
Objective
Biomarker
Barrier Quality Keratin 1,10,11
Barrier Integrity and Cohesion
Total Protein
Dryness Induced Irritation
and Redness
Hydration
IL1-ra/IL1-α
Pyrrolidone Carboxylic Acid (PCA)

Biomarker Sampling and Analysis Approach
“Non-invasive sampling of stratum corneum”
Sampling Sites
● Leg
● Arm
● Targeted Multiple Analyte Assay
- Multiplexed ELISA
- LC/MS/MS
● Colorimetric Assay for Protein
- normalize targeted analyte data
1) Apply D-Squame Tape 2) Remove Tape 3) Extract Analytes 4) Analysis Samples

Protocol
• Standard Leg-Controlled-Application Testing (LCAT) protocol 2 was used
in this study with a minimum dryness entrance criteria of 2.0 (0-5 scale,
0=no dryness) during winter season.
• The following products were applied once a day.
– Leave-on lotion containing petrolatum;
– Advanced petrolatum-depositing body wash;
– Regular body wash containing sodium laureth sulfate, sodium lauryl
sulfate and cocamidopropyl betaine.
• A total of ten consecutive tape strips were taken for biomarker analysis at
the baseline and at week 1, 2, and 3 of product usages, respectively.
• The same panelists returned in the summer and their skin biomarkers
were measured to understand seasonal effect.

Winter vs. Summer: Traditional Measures
Measures
Winter
Summer
P values for
(n=27)
(n=27)
pair wise
comparison
Dryness (mean) 2.8 ± 0.2 1.7 ± 0.2 P

Winter vs. Summer: Keratin 1, 10, 11
Keratins 1, 10, 11 higher in summer vs. winter.

Winter vs. Summer: Total Protein
Total protein lower in summer vs. winter.

Winter vs. Summer: IL1-ra/IL1-α Ratio
IL1-ra/IL1α ratio lower in summer vs. winter.

Winter vs. Summer: Pyrrolidone Carboxylic Acid
Pyrrolidone carboxylic acid higher in summer vs. winter.

Leave-on Lotion: Pyrrolidone Carboxylic Acid
35
30
% Change vs. Vehicle
25
20
15
10
5
0
-5
0 5 10 15 20 25
Days
p< 0.0001
Leave-on lotion increased PCA level over time.

Advanced Body Wash: Keratin 1, 10, 11
%Change vs. Water
200%
150%
100%
50%
0%
-50%
Normalized Keratin 1,10,11
p

Advanced Body Wash: IL1ra:IL1αRatio
50%
%Change vs. Water
0%
-50%
-100%
-150%
Advanced BW
P

Regular Body Wash: IL1ra:IL1αRatio
100%
%Change vs. Water
50%
0%
Regular BW
P

TEWL vs. Biomarkers
TEWL Actual
6.5
6
5.5
5
4.5
4
4.0 4.5 5.0 5.5 6.0 6.5
TEWL Predicted P

Skin Biomarker Summary
Biomarkers
Summer
vs. Winter
Leave on
Lotion
Advanced
Body Wash
Regular Body
Wash
Keratin 1, 10,
11
↑ ↑ ↑ =
Total Protein ↓ ↓ ↓ ↑
IL-1ra/IL-1α ↓ ↓ ↓ ↑
PCA ↑ ↑ ↑ ↓

Conclusion
• Xerotic skin showed different skin biomarker profile vs. normal healthy
skin (winter vs. summer).
• For the first time in the rinse-off context, the advanced petrolatumdepositing
body wash is shown to significantly improve barrier function
and quality through biomarker measures in-vivo, similar to leave-on lotion.
• Regular body wash causes damage to skin barrier function and quality as
revealed by the worsening trend of most biomarkers.
• Biomarkers provide objective, non-invasive, and consistent measures of
stratum corneum barrier function and health for guiding the development
of superior personal care formulation.

References
1. Engelke M, Jensen JM, Ekanayake-Mudiyanselage S, and Proksch E. Effects
of xerosis and ageing on epidermal proliferation and differentiation. British
Journal of Dermatology 137; 219-225 (1997).
2. Ertel K, Neumann PB, Hartwig PM, Rains G, and Keswick B. Leg wash protocol
to assess the skin moisturization potential of personal cleansing products.
International Journal of Cosmetic Science 21; 383-397 (1999).
3. Rawlings AV, Harding CR, Watkinson A, and Scott IR. Dry & xerotic skin
conditions. In: Skin Moisturization (J.J. Leyden and A.V. Rawlings, eds), pp.
119-143 (2002).
4. Laden K and Spitzer R. Identification of a natural moisturizing agent in skin. J.
Soc. Cosmet. Chem. 18, 351 (1967).

This work was funded by P&G Beauty & Grooming