This document discusses the role of moisturizers and humectants in dry skin. It begins by defining moisturizers as mixtures that help hold water in skin using occlusives, humectants, and emollients. Humectants attract moisture into skin cells while emollients smooth skin surfaces. The document then examines care for dry skin and the role of trans-epidermal water loss before exploring how moisturizers work to hydrate skin and protect its barrier function. It also defines humectants like glycerin and their ability to bind water. The document concludes by providing formulations for a cream moisturizer and moisturizing lotion.

1. Role of moisturizers and
humectants in dry skin
Presented by,
Mr. Akash U. Thakur
M. Pharm IInd sem
Dept. of Pharmaceutics
DBCOP Besa, Nagpur.
Guide,
Dr. Mrs. U. N. Mahajan
Dept. of Pharmacognosy
Principal, DBCOP Besa, Nagpur.

2. Contents
 Moisturizers
 Care for dry skin
 Trans-epidermal Water Loss
 Role of Moisturizers
 Mechanism of action of moisturizer
 Uses of moisturizers
 Humectants
 Role of Humectants
 Formulations
 Reference

3. Moisturizers
 Moisturizers are complex mixtures of chemical agents often occlusive help
hold water in the skin after application, humectants attract moisture
and emollients help smooth the skin.
 They increase the skin's hydration (water content) by reducing evaporation.
Naturally occurring skin lipids and sterols, as well as artificial or
natural oils, humectants, emollients, lubricants, etc. may be part of the
composition of commercial skin moisturizers. They usually are available as
commercial products for cosmetic and therapeutic uses.

4. For treating skin dryness, the most appropriate moisturizers are heavier, oil-based
moisturizers that contain ingredients such as antioxidants, grape seed
oil or dimethicone. For very dry, cracked skin, petrolatum based products are
preferable, as they are longer-lasting than creams and are more effective in preventing
water evaporation.

5. Care for dry skin
 During the winter months, it’s important to reach
for skin care products that contain hydrating and
nourishing ingredients that will work hard for your
skin to fight the weather’s dehydrating effects.
 Most moisturizers contain a mixture of three groups:
 Humectants, Emollients, Occlusive.
 Humectants -
such as glycerin, sorbitol, urea, propylene glycol, alpha
hydroxy acids and sugars work by attracting water into the skin cells.

6.  Emollients -
The creams, ointments and lotions, work to fill the spaces between rough or peeling
skin cells, smoothing the surface of the skin. Think products that contain ingredients like
plant and mineral oils, shea and cocoa butter, petrolatum and plant oils like lanolin.
 Occlusive -
which include petrolatum, paraffin and lanolin, form a barrier on the epidermis,
preventing water from being lost when the skin is exposed to dry air or wind.
 Examples include well-known moisturizing ingredients such as hyaluronic acid,
glycerin, ceramides, essential oils, urea, lactic acid, petrolatum, raw honey and
aloe vera.

8. What is Trans-epidermal Water Loss (TEWL) ?
When water passes from the dermis through the epidermis and evaporate from the skin’s
surface, this known as transepidermal water loss.
As the it is in large scale causes dry skin.
To maintain desirable levels of TEWL your skin needs both hydration and moisturization.
Hydration refers to water content of skin and this can be imparting with the agents known
Humectants.

9. An Ideal Moisturizer Should
 Reduce and prevent further TEWL.
 Restore lipid barrier, i.e., duplicating and enhancing the skin's
moisturizing retention mechanisms.
 Hypo-allergenic, non-sensitizing, fragrance free.
 Absorbed immediately, providing immediate hydration.
 Cosmetically acceptable.

10. Role of Moisturizers
 Moisturizing action :
This is the most vital action by which they increase the water content of the
SC. Hydration smoothens the skin surface by flattening the “valleys” between the
skin contour ridges. It also makes the skin surface soft, more extensible, and
pliable. The moisturizing action of emollients is evident maximum 30 min - 1hrs
after their use and usually lasts for 4 hrs.
 Anti-inflammatory action :
Many moisturizers inhibit the production of pro-inflammatory prostanoids by
blocking cyclooxygenase activity thus have a soothing effect on inflamed regions.

11.  Antimitotic action :
Moisturizers containing mineral oils have low-grade anti-mitotic action on the
epidermis and thus are useful in inflammatory dermatitis like psoriasis, where there
is increased epidermal mitotic.
 Antipruritic action :
This reducing the itching. Further more, cooling effect evaporation of water
from the skin surface after using water based moisturizers has antipruritic effect.

12.  Protective action :
These days sunscreens with variable sun protection factor are incorporated in the
moisturizers providing additional sun protection.
 Miscellaneous actions :
 Quality of life improvement: Having a smooth and hydrated skin plays a good role
in our social life and psychological satisfaction.
 Antimicrobial action: Act against skin surface microbes.
 Wound healing: Hyaluronic acid is known to play a role.

13. Mechanism of action of moisturizer
1. Increasing water diffusion from the living cells of epidermis into the horny layer
through the barrier. This can achieved by chemically disrupting the epidermal barrier in
the lowermost horny layer.
2. By adding water directly from outside, or by strengthening of lipid framework in the
stratum corneum to maintaining the hydration level of skin.
3. By occluding the surface to prevent
evaporation of water and increases
the water holding capacity of stratum
corneum which gives plasticity
to the skin.
Fig. Mechanism of action of moisturizer in prevention of TEWL

14. Examples
 Hydrocarbon oils and waxes.
e.g. Mineral oil, petroleum, paraffin microcrystalline wax.
 Silicone oils.
e.g. water and alcohol soluble silicone glycol copolymers.
 Triglyceride esters. e.g. vegetable & animal oils and fats.
Fatty acids. e.g. cetyl alcohols.
Lanolin and derivatives. e.g. lanolin, lanolin oil, lanolin wax, lanolin alcohol, lanolin
fatty acids
Sterols. e.g. Cholesterol, cholesterol fatty acids esters.

15. Uses of moisturizers
 Disorders of keratinization. e.g. Ichthyosis.
 Disorders of dermatosis . e.g. Dermatitis.
 Maintenance of skin integrity in special population.
 Miscellaneous uses. e.g. Contact dermatitis.

16. Humectants
 Hydrating substance are used in cosmetics products to retard moisture loss and
increase the moisture content in skin that is in contact with the products.
 Target area in the body for treatment with humectants are dry skin.
 Hydration plays an important role in maintaining the metabolism, enzyme activity,
mechanical properties, appearance, and finally barrier function of skin.

17.  The special blend of humectants found in the stratum corneum is called as natural
moisturizing factor (NMF).
 The NMF is formed from the protein filaggrin, mutation in filaggrin gene have
been identified as the major predisposing factor for atopic eczema.
 The water binding capacity of sodium salt of lactic acid and 2-pyrrolidone-5-
carboxylic acid (PCA) appear to be higher than that of glycerin and sorbitol.
 The humectants solutions shows that the water held by corneum decrease in
following order sodium PCA > sodium lactate > glycerin > sorbitol.

18. ROLE OF HUMECTANTS
 Without getting to technical, the key functionality of a humectant, is to
form hydrogen bonds with molecules of water.
 humectants are considered an important ingredient for a dry, dehydrated
skin.
 The reason adding a humectants to due to they ability to attract water
like a magnet, chemically binding water to them.

19. Humectants
Glycerin
Alpha
hydroxyl
acid e.g.
glycolic
acid, lactic
acid
Sorbitol
Honey
Propylene
glycol and
butylene
glycol
Panthenol
Hyaluronic
acid
Aluminum
lactate and
Sodium
lactate
Urea

20. Butylene glycol
 Butylene glycol means 1,3-butanediol,but the term can also be used for 2,3-
butanediol.
 The alcohol is a viscous, colorless liquid with sweet flavor and bitter
aftertaste. It is soluble in water, acetone, and castor oil.
 Uses
It is used as a humectant in topical products and solvent for injectable
products.

21. Sorbitol
 Sorbitol is hexahydric alcohol white crystalline powder, odorless and having
fresh and sweet taste.
 It is most commonly available as 70% aqueous solution, which clear colorless,
and viscous.
 used as a laxative

22.  The importance of glycerin in skin care products is well established.
 Glycerin not only attracts water but also has been suggested to modulate the
phase behavior of stratum corneum lipids.
 The mode of action of glycerol on both stratum corneum hydration and
epideramal barrier.
 Glycerol is transported very slowly into the epidermis and it’s transport rate
is sensitive to the intrinsic glycerol permeability of the basal keratinocyte layer.
Glycerin -

23. Propylene Glycol
 Propylene glycol is clear, colorless, viscous liquid.
 Propylene glycol has been used in the treatment of skin disorder including
dermatitis, due to its humectant, antibacterial and antifungal properties.

24. Cream Moisturizer -
Moisturizering Lotion -

25. Sr. No. Ingredients Quantity Uses
1 Lanolin alcohols 10% Moisturizer
2 Lanolin 20.0 Absorption base
3 Mineral oil 35.0 Reduce the tacky feel of
lanolin alcohol
4 Water 34.0 Solvent
5 Perfume 0.5 Imparting Fragrance
Cream Moisturizer -

26. Moisturizering Lotion -
Sr.
No.
Ingredients Quantity Uses
Part A
1 Lanoline 1.00 % Prevent dryness ,itchy etc.
2 Mineral oil(65/75) 12.00 % Reduce water loss from the skin.
3 Pectin 1.00 % Increases the thickness of the aqueous
(water) portion of cosmetics
Part B
4 Boric acid 2.00 % Prevent or retard bacterial growth
5 Cetyl tri-methyl ammonium
bromide
0.16 % Cleanse the skin or to prevent odor
6 Water 83.74 % Solvent
7 Perfume 0.10 % To produce Aroma

27. Reference
 Martin M. Reiger “Harry’s Cosmeticology” Chemical Publishing Co.,Eighth
Edition, Volume 1 of 2, Page no. 261–271.
 Andre O. Barel, Marc Paye, Howaerd I. Maibach “Handbook of Cosmetic
Science and Technology” CRC Press, Fourth Edition, Page no. 93–100.
 Hilda Butler, “Poucher’s ” Springer International, 10th Edition, Page no. 427-
428.

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