Barrier

The skin is our body’s largest organ. It serves as a barrier to the external environment and is the first layer of defense to harmful toxins, mechanical forces, UV and harsh swings in climate.

The outermost layer of the skin is called the stratum corneum. This layer is made of corneocytes in a continuous phase of lipid bilayers, an arrangement commonly referred to as the brick and mortar architecture. The stratum corneum is 10 to 20 microns thick, and may be thicker depending on the anatomical location. While the underlying epidermis is viable, the stratum corneum is dead and sluffed off over a period of 2 weeks to four weeks.

In the stratum corneum, glycerin maintains the right balance of lipid bilayer crystallinity and fluidity to sustain the skin barrier integrity (Froebe et. al, 1990).

Sagrafina et. al (2024) found that glycerin maintained lipid cohesion and did not increase the transepidermal water loss, when compared with urocanic acid, another natural moisturizing factor in skin. 

As we age, the complex biological process responsible for building a normal stratum corneum begins to falter, leading to barrier dysfunction. Geriatric skin, as a result, is commonly, itchy, dry and flaky, and in need of skin moisturization.

Numerous studies have demonstrated the skin hydration and barrier recovery benefits of topically applied glycerin to barrier compromised skin.

Barrier compromised skin also includes atopic dermatitis, irritant dermatitis, psoriasis, brachioradial pruritis and xerosis.