Cosmeceuticals and the Regulatory Environment

Cosmeceuticals, from a consumer standpoint, are believed to be a category of skin care products that function as active cosmetics going beyond mere adornment and scenting of the skin. Yet, from a regulatory standpoint, cosmeceuticals is an unrecognized term with no meaning, because cosmeceuticals are purely cosmetics and viewed as such in the United States. In dermatology, cosmeceuticals are believed to encompass the topical application of biologically active ingredients, which affect the skin barrier and overall skin health. The ability of cosmeceuticals to enhance skin functioning depends on the incorporation of ingredients into a topical vehicle that maintains the integrity of the active, delivers the active in a biologically appropriate form, reaches the target site in sufficient quantity to exert an effect, and properly releases the ingredient from the carrier vehicle. Clinical testing using the scientific method for efficacy assessment must be performed to document the value of the cosmeceutical.

Because cosmeceuticals are considered cosmetics, safety to the consumer is of key importance. Most cosmeceuticals are formulated from ingredients that already have a proven safety record in the marketplace. This situation may be because of their extraction from foods, such as topical lycopene from tomatoes or topical avocadin from avocados. Alternatively, extensive animal testing may be undertaken by the raw material supplier to determine that the new ingredient is appropriate for human use. In the case of botanicals, most are assumed safe based on their ubiquitous nature. To avoid regulatory issues, most cosmeceuticals use ingredients that are generally recognized as safe, which is how cosmetics are also formulated.

This article discusses cosmeceuticals and their efficacy. It examines available testing methodologies used to better understand how cosmeceuticals affect the skin and the various mechanisms of action cosmeceuticals use to improve skin appearance. The discussion focuses on skin tone and what this term means in persons of African descent and how problems can be avoided when using cosmeceuticals in skin of color.

Development of Scientific Substantiation

Cosmeceutical formulations must be tested for 3 important reasons: (1) to determine that they provide a benefit that is perceived by the consumer; (2) to establish that the formulation is safe and free of adverse reactions; and (3) to support marketing claims. Consumers purchase a new cosmeceutical once based on the name, promises made on the packaging, recommendations from advertising or acquaintances, appearance, and fragrance. However, the consumer does not repurchase a product that is not perceived to work. In many regards, the consumer is the most discriminating grader when it comes to cosmeceutical preparations. Most cosmetic companies carry out extensive consumer testing before a product is released into the marketplace. This testing is then backed up by dermatologist-led testing to determine efficacy but also to ensure that the product does not cause any adverse reactions, such as allergic contact dermatitis, irritant contact dermatitis, comedogenicity, or acnegenicity. Testing is sometimes performed in conjunction with an ophthalmologist to ensure that no eye issues arise as a result of accidental eye instillation.

In addition to clinical testing to assess consumer subjective evaluations and dermatologist objective evaluations, noninvasive testing is also performed to confirm the visual and tactile observations. Noninvasive testing is used because it does not enter the body and evaluates skin performance by placing electronic sensors or devices on the skin to gain insight into skin functioning. This type of testing allows product evaluation without the traditional biopsy that is used for medical diagnostic purposes. If a cosmeceutical manufacturer made claims based on biopsy information, such as “this cream increases type III collagen production,” it could be considered a drug. Noninvasive testing avoids this conundrum and allows efficacy evaluations in a scientific manner without entering the skin.

The need for scientific substantiation of cosmeceutical performance has led to the development of skin bioengineering. Skin bioengineering develops equipment to assess skin functioning before and after product application to detect small changes that might not be visually or tactilely perceived ( Box 1 ). Sometimes, clinical studies must be run in 4 to 12 weeks for practical reasons, and it is hoped that small skin improvements might become magnified over time with continued use. Usually, noninvasive results parallel clinical results in an efficacious formulation.

The most common claim for substantiation in cosmeceuticals is skin moisturization. Moisturization can decrease fine lines of dehydration, improve skin smoothness, decrease itching, and increase light reflection from the skin surface. All of these benefits enhance the visual, tactile, and sensory functioning of the skin. Corneometry is the technique used to determine how much water is present in the skin, which is one way of assessing skin moisturization. Corneometry uses a probe that emits and receives low current electricity. The electrical current is transmitted into the skin by the sending portion of the probe and received. This measure is an indication of the electrical conductivity of the skin. Because water is an excellent conductor of electricity, skin water content can be measured. More water in the skin correlates with better skin appearance and functioning, translated to the consumer as better skin moisturization. Thus, corneometry is the noninvasive bioengineering assessment technique used to substantiate claims of enhanced skin moisturization.

Moisturization can also be evaluated by assessing the integrity of the skin barrier. An intact skin barrier prevents water loss and encourages superior skin moisturization, whereas a damaged barrier encourages transepidermal water loss. The noninvasive test to measure transepidermal water loss is evaporimetry. Evaporimetry uses a probe that senses the humidity of the air directly above the skin. The probe contains 2 humidity meters, which are placed at known distances above the skin. The water vapor passes between the 2 fixed distance humidity meters through an orifice of known diameter. The difference in the observed humidity between the 2 meters is calculated. By comparing the amount of water leaving the skin before and after cosmeceutical moisturizer application, the effect of the moisturization on skin hydration can be determined. Quality moisturizers decrease transepidermal water loss in barrier-damaged skin. It is through the use of corneometry and evaporimetry that claims of “45% increase in moisturization in 10 minutes” can be substantiated.

Noninvasive techniques can also be used to assess the improvement in fine lines and wrinkles. This technique is known as profilometry. Profilometry uses unpolymerized silicone, in the form of dental impression material, which is mixed with a catalyst just before skin application. The polymerizing silicone is placed in a round form on the face, usually around the lateral eye, to capture wrinkling in the crow’s feet area. This area of the eye is used because it is the thinnest skin on the body commonly affected by dehydration, which is easiest to improve texturally with moisturizers. As the silicone polymerizes on the skin, a replica is obtained of the skin topography. The replica is a negative of the skin dermatoglyphics, showing mountains for depressed wrinkles and valleys where the skin surface is smooth.

Replicas are allowed to cure for 24 hours and then analyzed with a scanning laser to determine the depth, number, and contour of the wrinkles. Computer imaging can transform the scan into a two-dimensional or three-dimensional topogram, which can be used in advertising and on packaging to convince consumers of the capability of the moisturizer to reduce fine lines. Scientifically, before and after replicas are compared to determine the effect of the moisturizer on skin fine lines and wrinkles. This is the method used to substantiate claims of “56% fine line reduction in 5 days.”

Bioengineering methods can also be used to assess color changes in the skin through techniques known as chromametry and Doppler flowmetry. Chromametry uses a colorimeter, originally developed to match paint colors, to evaluate the color of the skin on 3 axes known as L, a, and b. The colorimeter can give readings to assess skin color changes in terms of all hues, but usually brown and red pigmentation are assessed. Claims of improved skin color, radiance, and luminosity can be substantiated through chromametry.

Skin redness can also be measured in terms of blood flow alterations with a technique known as laser Doppler flowmetry. This technique makes use of the Doppler effect to measure the speed of blood flow in the skin. Enhanced blood flow equates with increased skin redness. Although adequate blood flow is necessary to have pink healthy skin, too much blood flow indicates inflammation and equates with the red face of dermatologic disease. However, increased blood can minimize the sallow appearance of photodamaged skin. A few cosmeceuticals contain botanic vasodilators to improve skin color and substantiate these claims using flowmetry.

All of the noninvasive techniques previously discussed are used to add further information to subjective patient assessments and visual trained observer assessments. They are not a substitute for good clinical testing. The human eye is still the best measure of cosmeceutical efficacy. Most cosmeceutical claims are based on the evaluations of the subject and the investigator, which are accurate if the study is a well-designed double-blind vehicle-controlled trial.

Cosmeceutical Development

Many ingredients are derived from a variety of different sources that are used in cosmeceutical formulations. The possibilities are endless, given the sophistication of the plant kingdom, providing more variety than is currently available in pharmaceuticals. The development process for new cosmeceutical ingredients combines exploration with analytical chemistry with sophisticated gene chip arrays, cell culture models, animal studies, and human trials, similar to the methodology used to develop new pharmaceuticals. The only missing piece of information is the dose, because cosmeceuticals are not intended for ingestion. The cosmeceutical development process is summarized in Box 2 .

Cosmeceutical Claims

Cosmeceuticals are defined by the claims that are made regarding their intended use. A product that eliminates wrinkles is a drug, whereas a product that minimizes the appearance of wrinkles is a cosmetic, even although they may both contain the same ingredients. It seems unscientific to define product functioning based on package labeling and advertising, yet this is our current level of sophistication. Cosmeceuticals that function too well would alter the structure and function of the skin and become drugs. The current state of the cosmeceutical marketplace is not a result of the industry’s lack of desire to perform thoughtful research and develop quality products but rather a result of limitations imposed by the present regulatory climate regarding product claims. Thus, cosmeceuticals are cosmetics and only appearance claims can be made rather than functional claims.

Mechanism of Action for Cosmeceuticals

Currently marketed cosmeceuticals provide skin benefits through a few well-established mechanisms of action. The two of primary importance are barrier enhancement and photoprotection. These are activities that modify the stratum corneum, which is nonliving, and clearly fall within the intended cosmetic realm. The remainder of the cosmeceutical functional categories alter the structure and function of the skin, making them drugs and not cosmetics. Yet, there are products in the marketplace that contain ingredients functioning through these mechanisms, but the claims made are appearance claims and not functional claims, allowing them to be sold as cosmeceuticals.

Cosmeceuticals and Skin Tone

The general public perceive cosmeceuticals as creams and lotions that can magically improve the appearance, feel, and condition of their skin. Some even believe that cosmeceuticals can turn back the effects of excessive sun exposure and photoaging. Much of this belief accounts for the hope in the jar opinions that many dermatologists have regarding cosmeceuticals. True efficacy must be separated from marketing gibberish to accurately evaluate this category. It is hoped that this article clarifies some of the issues. Improper use of cosmeceuticals can cause problems, especially in persons of African descent. The rest of this article focuses on cosmeceuticals and their ability to alter skin tone. Although skin tone is a cosmetic term without scientific meaning, skin tone is generally used to denote skin color in combination with skin firmness.

The most popular cosmeceuticals used by persons of African descent are aimed at improving skin pigmentation. Many OTC products contain 2% hydroquinone, which can be a cutaneous irritation. Other pigment-lightening products may contain glycolic or salicylic acid and are intended to improve pigmentation temporarily by inducing exfoliation of the pigmented corneocytes. These low pH ingredients can further irritate the skin, resulting in postinflammatory hyperpigmentation. Skin irritation only darkens skin of African descent; it does not produce the intended lightening.

Other popular cosmeceuticals are cleansers designed to improve skin pigmentation. Many of these products combine surfactants with particulate scrubs, such as nut pits or polyethylene scrubbing beads. The idea is to scrub away the abnormal pigmentation. These products again can cause skin irritation by damaging the stratum corneum and viable epidermis, causing increased rather than decreased pigmentation in persons of African descent. Other scrubbing devices, such at home dermabrasion machines, aggressive mechanized facial brushes, and needling devices, should also be avoided, because they may induce postinflammatory hyperpigmentation.

Persons of African descent should focus on the use of sunscreen-containing moisturizers, which decrease transepidermal water loss, minimize barrier damage, and provide photoprotection. Sunscreen-containing moisturizer should be selected with a minimum SPF 30, because lower SPF products may not have adequate UV-A photoprotection, which is the action spectra for facial pigmentation. Ideally, the sunscreen-containing moisturizer should combine both organic and inorganic filters to both absorb and reflect UV radiation. The moisturizer improves skin firmness by increasing skin water content, and the sunscreen prevents dyspigmentation, resulting in a net improvement in skin tone.

Further photoprotection in persons of African descent can be achieved by applying a facial foundation. Colored cosmetics can be an excellent source of photoprotection. Facial foundation contains iron oxide, zinc oxide, and kaolin, all of which can provide physical broad-spectrum photoprotection. Many facial foundations now contain organic and inorganic sunscreens.