1. Emollients in Atopic Skin Care
K.Pytkowska, J.Arct, S.Majewski
Academy of Cosmetics and Health Care,
Warsaw, Poland

2. Skin in AD Impaired barrier function Inflammation
Secondary factors deteriorating barrier condition
Main factor influencig bad epidermal barrier condition are:
Changes of s.c. lipids composition
Disorders of epidermal cell differentiation
mutation of fillagrin encoding gene – low NMF level, changes of s.c. pH

3. Skin in AD
Disturbances in lipid composition and intercellular cement organization
Disturbances of pro-lipids in s.g. lamellar bodies
Disturbances of enzymatic processes in s.g.-s.c . borderline region
Improper formation of corneocyte envelope
Atypical s.c. lipids composition– changes in fatty acids profile, lower ceramide level
„Rigid” gel phase dominates in s.c. cement, loose corneocyte packing

4. Skin care in AD Washing Solutions:
Hard water indirectly disturb the barrier
Mechanism: exscessive use of surfactants („more effective washing”)
Solutions:
Elimination of SLES from cleansing products dedicated to the atopic skin care
Increase of refattening agents concentration in cleansing products
Addition of starch or other HMW hydrophiles to the formulation or bath

5. Atopic skin care – most frequent guidelines
Avoiding soap in favour of syndets with acidic pH
Avoiding washing formulations based on surfactants in favour of cleansing emollients

6. The most frequent guidelines
Regeneration of the epidermal barrier using emollients , and the emollients are most often selected by a trial and error method.
Avoiding cosmetics of strong occlusivity (continuous occlusion)
Continuous occlusion
Impairs regeneration of damaged epidermal barrier (ceramide synthesis inhibition)
Increase of the skin surface pH (mechanism - ?, multi-factor probably)
Mogą sprzyjać rozwojowi patogenów
No clinical trials evaluating the influence of physicochemical form and/or lipid level.

7. Emollients and the epidermal barrier
Effects:
Decrease of TEWL
Itch suppression (stress reduction, avoiding excoriation etc.)
Mechanism of action
Complementation or modification of the natural lipid barriers of the skin
Superficially
In the s.c. cement
Biological activity leading to the normalizing of the barrier restoration
EFAs and some other PUFAs and their derivatives, some sphingolipids

8. Emollients and the epidermal barrier
Evaluation of barrier regeneration process
Models:
SLS barrier damage (washing out of superficial lipids, selective sterol extraction, SLS – s.c. lipids interactions, in vivo - often inflammation)
Acethone barrier damage (washing out of superficial lipids, partial s.c. lipid extraction)

9. Emollients and the epidermal barrier
Evaluation of the barrier recovery
Results:
Hydrocarbons– recovery enhancement (via water content recovery, probably)
Sterols improve barrier condition after SLS damage
Pseudoceramides – direct s.c. cement restoration (no biological effect)
So called „physiological lipids” (CER:CHOL:FFA=3:1:1, ) – restoration of normal pathway of recovery after acute barrier damage, penetration and recovery of lamellar bodies lipid composition is possible – direct and indirect activity

10. EFA cosmetic activity Physicochemical activity Biological activity
Direct influence on the structure of s.c. intercellular cement
LA supplementation in AD skin
Biological activity
Eicosanoid synthesis
PPAR activation

11. EFA in AD Oral supplementation
N-6 EFA: barrier function restoration or no significant effect
N-3 EFA: very slight effect or no effect
Topical application (emulsions containing up to 20% EFA-rich oils)
Efficient AD suppression
Better effect or no significant difference vs. „regular”, no EFA-containing emollients

12. „Regular” emollients and other cosmetics
Petrolatum-, „physiological lipids”-, nanolipid- and humectant-based emulsions were evaluated
Most frequently evaluated parameters:
Skin condition (flakiness, redness)
Subjective parameters (itching),
SCORAD or similar indexes
Self-evaluation of skin condition
TEWL, electrical parameters (indirect moisturization evaluation), superficial lipid level – less frequently
Emollient-rich and humectant-rich emulsions improve skin condition in AD
No significant difference in TEWL reduction after a long-term application

13. „Regular” emollients and other cosmetics
Product groups
Studies
Urea-containing products
Loden 2001 (25) , Loden 2002 (26)
Glycerine-containing emulsions
Loden 2001 (25), Loden 2002 (26), Matsumoto 2005 (27), Breternitz 2008 (28), Kikuchi 2008 (29)
Hydrophilic anti-inflammatory ingredient containing emulsions
Patrizi 2008 (30)
Moisturising emulsions containing hydrophilic moisturising ingredients
Vilaplana 1992 (31), Tabata 2000 (32), Loden 2003 (33), Matsumoto 2007 (34)
w/o emulsions
Lucky 1997 (35)
“Physiological lipids”-containing emollients
Mao-Qiang 1995 (22), Chamlin 2001 (36) , Berardesca 2001 (37), Sugarman 2008 (38)
Emulsions with siloxanes
Hagstromer 2006 (39),

14. „Regular” emollients and other cosmetics
Normalization of barrier function and water content in epidermis is of the greatest importance for therapeutic effect
Good effects:
Glicerin – prevents s.c. lipid phase transition in the low-humidity conditions, hygroscopicity, osmotic activity
Wet wrapping – decrease of water gradient
Synthetic semi-permeable membranes decreasing TEWL – evaluated in the SLS damaged barrier model

15. Future developement
Conscious linking both: direct- and indirect-active (biologically active) raw materials in the formulation.
Increase of hydrophilic raw materials significance
Better sensory parameters
o/w emulsions as preferred ones
„Light” emollients
„Nanolipids” containing formulations

16. Thank you for your attention