Skin is much more than the outer surface of the human body. It protects us from bacteria, dirt, the ultraviolet rays of the sun, and contains nerve endings that tell us if something is hot or cold, soft or hard. Skin also plays an important role in regulating body fluids and temperature.
Skin is the largest organ of the body. It consists of three layers: the epidermis, the dermis and the subcutaneous layer. The epidermis is the thin outer layer of the skin, also referred to as the stratum corneum. The outer layer of the epidermis consists of dead cells that are always sloughing off. These are replaced by new cells manufactured in the lower portion of the epidermis, which then move upward to the outside of the skin. As they do this, the cells harden and die. This cycle of cell production and replacement takes roughly 28 days.
There are smaller skin cells on the face than on the rest of the body. Because of this, facial skin is often more sensitive than skin on other parts of the body. Any chemical trying to get across the skin, whether it is water getting out or chemicals going in, has to negotiate its way through the barrier created by our skin cells. Since the skin cells on the face are smaller, they present less of a barrier to entry.
Our skin is designed to prevent evaporation of moisture from within its outermost layer. When the skin dries out, this protective ability is lost and the integrity of the skin suffers. For this reason, proper moisturizing is critical to both skin health and our comfort level. A good moisturizer supports two functions: it slows moisture loss and helps to draw water back into the stratum corneum.
There are two kinds of moisturizers, oil-based and water-based. Moisturizers contain different kinds of oil, and the ratio of water to oil varies from product to product. The type of moisturizer you choose should depend on your skin type. If your skin is oily, a water-based moisturizer will prevent the burdening of your pores with more oil. If your skin is dry to normal, an oil-based moisturizer works best to maintain hydration.
Many formulators like to extol and market the virtues of natural cosmetics. Here are a few widely-used natural ingredients found in skincare products on the market today:
• Alpha Hydroxy Acids (AHA’s) are used in a wide range of moisturizers and anti-aging creams. Glycolic acid is derived from sugarcane. Lactic acid from milk, malic acid from apples and tartaric acid from grapes are other natural acids. AHA’s are thought to improve skin tone and dark spots as well as to soften lines and wrinkles.
• Clay is rich in minerals and often used in facial masks, shaving products and soaps. It is an effective cleanser and considered hypoallergenic.
• Oat is a natural grain used in many cosmetics to soothe sensitive skin and relieve itching. It is also a humectant, which means it promotes the retention of moisture.
• Botanical Oils such as avocado, sunflower, olive and almond oil are commonly used natural ingredients, although some oils are considered comedogenic.
Ultimately, formulators should strive to understand the structure and function of the skin when formulating cosmetics. Having a grasp of the skins function in relationship to the cosmetic being formulated results in more effective products, which in turn will boost your bottom line.
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