The Skin and Cosmetics

How we treat our skin is part of living a healthy life. The skin is the body’s largest organ. It has been called the body’s armor because it keeps all the organs and muscles safe from the elements outside the body that can cause harm—like the sun’s rays, bacteria, insects, and irritating chemicals. In addition, the skin helps in regulating a number of the body’s functions, including temperature and eliminating toxic chemicals. Its most important role by far, though, is to keep the body’s water from evaporating. When we are born, 90 percent of our body is made up of water; as we age it reduces to 70 percent and might even drop as low as 50 percent in our later years. Without healthy, intact skin covering our body we would die.

Given the skin’s importance to our survival, it is essential that we learn how to take care of it, not only so that we look beautiful, but so we can also live long, healthy lives. From this perspective, it is important that all skincare professionals, from estheticians to physicians, have a good understanding of skin structure (anatomy) and function (physiology), skin types and conditions, as well as what happens when cosmetics or other products are applied to the skin. The same understanding is also important for cosmetic consumers, particularly given the amount of information and misinformation about cosmetics currently available. That is the purpose of this book—to better inform skincare professionals and their clients about how and why a product impacts the skin, and the purpose and function of individual ingredients in a cosmetic formulation.

Before moving into a discussion of the skin—its anatomy, physiology, typing and common problems—and its interaction with cosmetic ingredients and products, it may be helpful to concentrate a moment on the history of cosmetic ingredients and regulation. Cosmetics and the cosmetic industry are heading in directions that will be of great benefit to skin care professionals and cosmetic users, but in order to understand what these directions mean, it is important to understand the links between the past and the present.

Historically, people used common or everyday substances for beautifying, healing, soothing, or creating other effects. Cleopatra was well known for using sour milk on her skin. Today, we know that sour milk contains high levels of lactic acid, commonly referred to as an alpha hydroxy acid (AHA). In modern times, AHAs are considered to have launched the cosmeceutical revolution and represent the skincare ingredient category with the most significant impact on the cosmetic industry. In the second decade of the 2000s, sales of AHAbased products contributed well over a billion dollars a year to the anti-aging skincare market. Perhaps more importantly, however, this revolution changed how we look at skincare, and how we perceive the interaction of ingredients with the skin’s anatomy and physiology— not bad for a thought that started out with sour milk!

There are other interesting stories about how and why a variety of ingredients are used in skincare formulas. Most, if not all, come from folklore, often based on observation and passed down from generation to generation for hundreds if not thousands of years: rub the juice from the aloe plant on a burn and the skin will not blister; an extract from chamomile applied to irritated skin will have a calming effect; apply tea tree oil to acne skin. Scientists have examined such stories and have explored why these effect the skin. Today, they are able to isolate and develop purified versions of a botanical’s specific chemical constituents that have therapeutic value, creating versions that can be stronger and more effective for healing various skin care problems than the original treatment. This marks the beginning of the “synthetic versus natural” debate, a topic that is explored in more detail in Chapter 3.

The use of folklore as a basis for skincare and color cosmetics is also what launched government regulations in the cosmetic industry. In the 1930s (and before) there were many traveling shows that sold magical elixirs and lotions claiming to cure all varieties of aliments. Two major incidents occurred that caused the U.S. Congress to give the Food and Drug Administration (FDA) power over food, drug, and cosmetic products in 1938. The first was a magical “feel good” elixir that killed several people after they drank it. The main ingredient turned out to be anti-freeze, commonly used today in car radiators and chemically known as ethylene glycol. The second was a mascara called “Lash Lure.” It promised to stain eyelashes, so that it did not have to be used frequently. It also caused a dozen women to go blind and one to die. The product contained an ingredient called paraphenylenediamine or PPD, a very common ingredient that today is used safely in hair dyes, PPD may cause an allergic reaction in some people.

These incidents were the “straw that broke the camel’s back” and the FDA was charged with developing guidelines to protect consumers from food, drug, and cosmetic products that were potentially harmful. One of the first things that the FDA did was to place the responsibility of proving product safety on the manufacturer. If the manufacturer did not test the product and demonstrate that it was safe, then a warning label was placed on the product stating: “Warning: The safety of this product has not been determined.”

For the first time, the FDA also defined the terms drug and cosmetic. A drug was defined as “a substance that altered the structure or function of the body.” A cosmetic was defined as “any product, except soap, intended to be applied to the human body for cleansing, beautifying, promoting attractiveness, or altering appearances.” These definitions were part of the 1938 Food, Drug and Cosmetic Act and are still used by the FDA to regulate the cosmetic industry. While this appears straightforward, our understanding of the skin’s anatomy, physiology, chemical composition, and relationship to cosmetic ingredients has vastly improved since 1938. Thus, using a definition that is over 70 years old to govern cosmetic chemistry, a science that changes dramatically every few years, has significant consequences.

In 1938, skin was commonly considered a dead tissue, and thought to be almost completely impermeable. Keeping it clean and applying makeup to “alter the appearance” was more than an adequate way to describe what a cosmetic product should do. However, in the 1980s doctors Van Scott and Yu patented AHA technology.
In their patent, they illustrated that these ingredients could thin very thick skin by exfoliation, plump up skin by increasing the water-binding materials naturally found in skin called humectants (e.g., hyaluronic acid), and help minimize lines and wrinkles by stimulating the production of such materials as collagen, giving the skin a stronger base or foundation. All of these changes in the skin demonstrate an altering of its “structure and function,” which according to the 1938 FDA definition, would be considered drug claims. Yet, as mentioned earlier, AHAs have revolutionized the cosmetic industry and are found in many skin care products.

This complexity is also seen in reverse: products once treated as cosmetics might now be classified as drugs. Many people experience severe skin chapping and cracking—sometimes to the point of bleeding— during winter months. This can often be due to a combination of water plus a cold temperature and low humidity outside. In the 1970s a group of estheticians were given a jar of 100 percent Petrolatum (commonly called Vaseline®) and several pairs of cotton gloves; each night before bed they were to apply the Petrolatum to their hands, put on a pair of the gloves, go to sleep, and in the morning remove the gloves and wash their hands with a gentle soap or cleanser. All of them disliked this routine, but within three to five days their skin was once again soft and supple. Technically, this too is altering skin structure and function and therefore given the FDA’s definition, Petrolatum should be considered a drug. In fact, today, a jar of Vaseline® carries a “drug fact label” and indeed it is now marketed as an over-the-counter (OTC) drug.

So, what is the difference between the two cases? Both AHAs and Petrolatum change the “structure and function” of skin. Both significantly impact the skin, though their mechanisms of action (how they work) are different. Yet AHAs are sold as cosmetics and 100 percent Petrolatum is sold as an OTC drug. What then permits the 1938 FDA law to classify them differently? Is it the concentration of the ingredient in question? There are no concentration limits set by the FDA for AHA products because they are cosmetics; however, products that contain 30 to 100 percent Petrolatum are generally sold as OTC drug products. Does that mean that any product containing 30 to 100 percent Petrolatum is an OTC drug? These are all very logical questions, but it is difficult to use strict logic to answer the questions as such logic has little to do with how the regulation is applied. What matters when constructing an answer to the question, and thus what forms the basis for the classification, is what the manufacturer claims or says about the product and its activity on the skin. Regardless whether the ingredients actually impact the skin’s structure, function, or mechanism of action, and independently of their concentration, regulations only apply if the product or ingredient(s) are discussed in ways that can be interpreted as a drug or pharmaceutical claim. AHA-based products are sold as skin moisturizers, and their packaging and advertising will generally read: “apply this luxuriously rich moisturizing cream day and night for younger more radiant looking skin.” This is a cosmetic claim because it refers to “altering the appearance” of the skin—that is, skin looks more youthful and radiant; it is not claiming to make the skin more youthful and radiant. In the case of Petrolatum, products containing 30 to 100 percent Petrolatum usually state “For the temporary relief of chapped skin or lips.” This is a drug claim because it refers to “altering the structure” of your skin— that is, chapped skin or lips are relieved of their condition, at least temporarily.

The 1938 FDA law has not kept up with science. Our understanding about what happens in skin when an ingredient or product is applied to it—biochemistry—as well as being able to measure these changes down to the cellular level—analytical chemistry—has become extremely advanced. These capacities did not exist when the FDA developed its law. Today, one can say that almost all ingredients impact the “structure or function” of the skin in one way or another. This being the case, it would appear that the only way the FDA can enforce the 1938 Food, Drug and Cosmetic Act is by either establishing “logical standards,” which would require receiving a significant increase in resources (funding, equipment, and personnel); or by continuing to let the cosmetic industry regulate itself. The cost to redefine this almost two hundred billion dollar global industry is more than most governments are willing to do. This is especially the case since the cosmetic industry has caused very minimal problems worldwide.

Any confusion is compounded by differences in regulation between the United States and Europe, for example. It is also a potential problem in light of the vast number of new ingredients and skin care concepts available to chemists, professionals, and consumers. The cosmeceutical revolution that began with AHAs has expanded and become even more sophisticated and effective. Botanically based products are experiencing a renaissance and renewed credibility as chemists and formulators become increasingly precise in their technologies and ability to isolate a botanical’s therapeutic components. Carotenoids, for example, as well as flavonoids, peptides, polyphenols, and phytoestrogens all fall into this category. Animal-based ingredients are now replaced with plant-based or synthetically manufactured equivalents, and even botanically derived ingredients have synthetic equivalents that are more frequently used for their purity and predictability. While anti-aging products still represent the lion’s share of cosmetic industry sales, there is also growing awareness of the importance of age and damage prevention and thus an emphasis on anti-oxidants, more UVA protection in sunscreens, and new sunscreen labeling requirements in the United States. Nanotechnology is still being researched and developed.

Now in its fourth edition, the aim of this book remains the same: to help skin care professionals and their clients solve the mystery of skin care product performance by helping identify what the ingredient does and why it might be incorporated into a product. Part I is dedicated to understanding the skin—its physiology, its various types and conditions, and how it interacts with cosmetic products. A large number of technical terms often used in cosmetic product development and formulation are introduced and briefly defined here as well. Part II provides a listing of the ingredients that are commonly found in today’s skincare cosmetics, both active principles and the ingredients that give a product its texture, color, stability, and acceptance by the skin and consumer. Finally, as ingredient labeling becomes more harmonized and it is increasingly common to find the Latin names of botanicals on an ingredient listing, Part III is a cross index of Latin names with the botanical’s “common” name that is generally found in Part II.