Topic Eight: Barrier Products and Emollients
Emollients and Moisturisers
Emollients and moisturisers are often used interchangeably. However, strictly speaking, an emollient simply acts as a barrier to prevent loss of the skin’s own moisture, whilst a moisturiser has added humectants (substances that increase the water content of the skin). Emollients can also have moisturising properties depending on the ingredients contained within the preparation.
Emollients are lipids (fats, waxes and oils) that occlude the skin surface, thus preventing water loss from the stratum corneum. Moisturisers are lipid emulsions that hydrate the skin by application to the skin surface (Voegeli, 2007).
Emollients work to moisturise the skin by increasing the amount of water held in the stratum corneum. Specifically, depending on the constituents of the emollients, they work either by occlusion, ‘trapping’ moisture into the skin (which slows the evaporation of water), or in an ‘active’ way by drawing moisture into the stratum corneum from the dermis.
The effect of emollients is short lived. Therefore, they need to be re-applied frequently. They are available as wash products such as bath additives, soap substitutes and skin cleansers or as topical preparations such as creams, ointments, gels, mousses and lotions.
Classification of Emollients
Lotions
Contain more water and less fat than creams. They are more watery preparations that contain the least oil and have a cooling effect when applied. Because they are non-greasy, they are useful for treating more hairy areas such as the scalp. Lotions may contain preservatives as the high water content may promote bacterial and fungal growth.
Creams
Contain a mixture of water and fat in variable proportions – oily creams contain more oils than simple creams. An emulsifier needs to be added to ensure an even mixture and to prevent separation. Once applied, the water tends to evaporate, although a small proportion may be absorbed by the epidermis. The most important effect is the thin film of oil left on the skin, trapping moisture within it.
Ointments
Ointments are the greasiest of moisturisers as they don’t contain water and provide an occlusive layer, reducing evaporation and trapping moisture in the skin. They are extremely helpful in treating very dry skin. Ointments are very resistant to bacteria and fungal contamination because they don’t contain water and, therefore, tend not to need preservative chemicals adding. Ointments work best when applied after soaking in a warm bath.
Application of emollients:
- Frequently and liberally
- At least three times a day
- After washing/showering whilst the skin is still moist
- Apply gently and generously smoothing emollient along the body following natural hair growth