SPF, Efficacy and Innovation

Today’s sun care products provide both protection and aesthetics. Elegant formulations available in a variety of formats now offer value-added benefits in addition to protection from UVA and UVB rays. The latest formulations take sun care products to another level. Some are boosting SPF levels with a combination of synergistic ingredients, some feature advanced polymer technology and others emphasize the benefits of antioxidant vitamins. When all is said and done, however, the primary aim of sun care products is to protect the skin from sun damage.

With the debate about the best way to get vitamin D and the controversy surrounding tanning beds, The Skin Cancer Foundation notes there is a great deal of misinformation surrounding ultraviolet radiation (UV). According to the foundation, “One thing is clear; UV radiation is known to be the main factor responsible for skin cancers, including basal cell carcinoma, squamous cell carcinoma, and possibly melanoma.”

UVA is long wavelength UV (320–400 nm) and accounts for up to 95% of the solar radiation reaching the earth’s surface. It can penetrate into the deeper layers of the skin, and is thought to be a major contributor to skin aging and wrinkling. The Skin Cancer Foundation also indicates that UVA has been shown in recent studies to possibly initiate and exacerbate the development of skin cancers.

UVB is the middle range of UV, with wavelengths between 290–320 nm. It is biologically active, and is responsible for burning, tanning, acceleration of skin aging and plays a key role in the development of skin cancer. It is clear that exposure to a combination of UVA and UVB is an attack on the skin, and protection from these rays is the way to avoid related problems.

The most important issue to understand about a Sun Protection Factor (SPF) rating is that it mainly indicates relative protection from erythema produced by UVB. In order to get protection against both UVA and UVB, a sunscreen with multispectrum, broad-spectrum or UVA/UVB protection should be selected. Additionally, The Skin Cancer Foundation suggests that the label should list an FDA-recognized long wavelength UVA sunscreen, such as avobenzone or zinc oxide.

Clearly, education about sun protection is an important part of the equation, and increased consumer awareness and global market demand impact product development in this area. Global sun care market statistics bear this out.

According to Euromonitor, the value of the global sun care market in 2005 was $5.6 billion, which was forecast to reach $7.2 billion by 2010. Figures for the U.S. market alone reached $1.1 billion in 2005, and were forecast to grow to $1.2 billion by 2010. Sun care protection, as well as self-tanners, held prominent positions within the category. Euromonitor says sun protection sales have been helped in recent years by educational efforts linking sun exposure to aging and skin cancer.

“Each year, more Americans understand the dangers of sun-tanning and its link with higher rates of skin cancer,” notes the Euromonitor report. In addition, media attention has focused on the aging effects of the sun, namely wrinkles and age spots. The addition of sunscreen to non-sun protection products, such as moisturizers and foundations, also has helped sales of sun protection products, and despite the fact that sun protection is a fairly mature category, value-added products were expected to drive growth of 2%.

Considering the size of the sun care market and the global regulatory environment that surrounds it, selecting effective products, and using them wisely and consistently, may be the greatest equalizer. Formats and delivery systems abound, from light body creams to oil-free sprays, and products offer everything from hydrating skin conditioners to hair color protection with SPF values. Recent innovations in delivery system technologies and ingredient synergies also are evident in today’s market. Of course, combining delivery system technology and aesthetics with key ingredients is integral to efficacy.

“When it comes to protecting the skin from premature effects of aging, it makes sense to use a high quality sunscreen product with adequate SPF protection,” says Karen Chen, marketing manager, skin care and makeup, Croda, Inc.

Sunscreens and Antioxidant Vitamins

Anna Gripp, senior technical marketing manager, DSM Nutritional Products, which offers UV filters and antioxidant vitamins for sun protection, discussed key components of an effective sunscreen.

“Obviously, the active ingredients come first, however, it is the appropriate combination of actives that achieves the desired SPF,” says Gripp. “It’s also the emulsifiers that are used, which are key in keeping a stable emulsion as well as playing a part in water-resistancy. Next, are the stabilizers in the system for the actives to get maximum effect. Water-resistant polymers and other ingredients are utilized to improve water-resistancy, and, finally, a preservative system plus SPF enhancers and stabilizers complete the list.”

Ingredient enhancements and synergistic combinations are key. “Basically, the most important components are the UV filters, and it would be important to use a combination of ingredients, whereby broad spectrum (i.e., UVA and UVB) protection is achieved,” added Gripp. Different combinations of actives are used to achieve high SPF protection.

Protective sun care benefits may be obtained by combining UVB/UVA filters with the antioxidant vitamins C and E, for enhanced skin protection. Sodium ascorbyl phosphate, DSM Nutritional’s STAY-C 50 product, is a more stable form of vitamin C. Avobenzone, supplied by DSM Nutritional as Parsol 1789, is an organic filter that has been approved for use in the United States since 1981. Unlike other organic UVA filters currently being used in sun care, which protect against shorter wavelength UVA, Parsol 1789 is said to provide broad-UVA spectrum protection, including the longer wavelength UVA I (340–400 nm).

“The inclusion of UVB filters and the FDA-approved broad-spectrum UVA filter, Parsol 1789, into sun care and skin care products, can provide an excellent protective shield. Unfortunately, even products with high SPFs of 30 plus, cannot completely block the entire spectrum of UV light,” says DSM.

“(Antioxidant vitamins )scavenge reactive oxygen species that are generated by exposure to UV radiation, and are deleterious to healthy cells,” says Gripp. “Antioxidant vitamins such as STAY-C 50 and vitamin E acetate have been shown to be effective in scavenging free radicals.” She cited a study by Kerry Hanson, et al., in the Journal of the Society of Cosmetic Chemists, November/December 2003 that supports these findings.

Some UV filters, according to DSM, such as its Parsol MCX may be used in combination with UVA filters and other UVB filters for higher SPF values as well as for skin care, color cosmetics and everyday protection—or as a photostabilizer for cosmetic products. These types of protection and treatment products allow marketers to include value-added options with the desired SPF to a variety of products.

New Formats

Application of sun care products has taken a new turn with the recent launch of a delivery format technology from National Starch Personal Care. The continuous spray form of sun care products proved to be very popular with U.S. consumers in 2006.

According to Maria Tolchinsky, marketing manager, National Starch Personal Care, “The products gained acceptance in virtually every sun care product category. As alcohol-based systems, these offerings deliver a fine mist spray for fast application, uniform coverage and best-in-class sensory properties.”

Formulators also can build in water-resistance properties with ingredients such as National Starch’s Dermacryl 79 film-forming polymer.

“This hydrophobic, high molecular weight carboxylated acrylic copolymer is soluble in alcohol, delivering water-resistance to fine mist sprays reliably and efficiently,” says Tolchinsky.

In addition, since sun protection has become part of the daily skin care regimen, moisturizers with SPF factors of 15 or more are now common in the market.

“These high SPF day-wear products are formulated with an eye toward moisturization benefits and luxurious sensory attributes,” says Tolchinsky. “The Hydrovance moisturizing agent diffuses into the stratum corneum to increase skin hydration, alleviate clinical signs of dryness and increase skin elasticity.

“This offering complements the Dermacryl AQF film-forming polymer introduced in 2003,” says Tolchinsky. “Makers of emulsions and aqueous spray products can use Dermacryl AQF film-forming polymer to maintain actives on the skin.”

As a liquid film-former, this water-resistance technology will not affect the rheology of day-wear moisturizers, according to Tolchinsky. With positive sensory attributes a must-have in products formulated with sunscreens, emulsion-based offerings are expected to feel good on application and dry down.

“Formulations considered as light, sheer and soft to the touch are more in line with consumer needs,” says Tolchinsky. “Innovative delivery technologies, like the continuous spray form, continue to capture the attention of consumers and drive sales.”

“One of the most important effects we can obtain from any sun protection product is UV protection with little or no generation of free radicals on the skin,” says Croda’s Chen. It is believed that free-radical damage causes a deterioration of the skin’s support structures, thereby decreasing elasticity and resilience. Chen notes that Croda offers sun care formulators the option to build in the benefits of free-radical scavenging with Optisol UV absorber, an inorganic sunscreen active made from a manganese modified titanium dioxide.

“Tests show that a portion of the manganese ions introduced into the structural lattice of Optisol are also associated on the external surface of the inorganic particle, providing the benefits of free radical scavenging on skin. By virtue of the free radical scavenging properties, Optisol actually reduces the free radical loading of sunscreen formulas, protecting the sunscreen actives from degradation while enhancing the photostability of the formulation,” says Chen.

Sunscreen Active Dispersion

“Croda’s Solaveil line of sunscreen dispersions, from (its) recent Uniqema acquisition, deliver the benefits of efficient and truly transparent UV protection with an optimized blend of carrier emollients that lend an elegant, nongreasy skin-feel to formulas,” says Mary Clarke, director of sales development, Croda.

According to the company, these dispersions of inorganic sunscreens offer formulators and marketers a ready-made solution for daily skin care products, premium beach sunscreens, sensitive skin care products and wipes where skin feel is a major selling proposition. Products in the line allow formulators to achieve both SPF targets and consumer-desirable sensory attributes with a 50% active dispersion, according to the company.

As previously cited, emulsifiers are among the essential components of efficacious sunscreens. “An important trend has been the move to convenient product forms, notably sprayables and, more recently, wipes,” says Clarke. “A limiting factor in formulating these novel sun care products has been the relatively restricted functionality of oil-in-water emulsifier systems. Uniqema solved this problem with the introduction of the Arlatone V-150 emulsifier system last year.”

The naturally derived emulsifier system is said to enable formulators to develop fluid, light emulsions that can be applied as a spray or coated onto a wipe. Arlatone V-150 emulsifier system, according to the company, provides flexibility in the choice of emollients and organic sunscreen actives and, unlike most traditional emulsifiers, has no impact on the sensorial properties of the finished emulsion.

Products and Protection

Finished products currently on the market provide numerous options for customers. Estée Lauder offers a response to the sun care conundrum with its Sun Performance SunCare Collection.

“Sun protection technology has come a very long way,” says Daniel Maes, vice president global research and development, Estée Lauder. “No longer are we solely reliant on sunscreens to protect our skin against harmful UVA and UVB. Significant advances in skin care research have revealed that, with the right balance of SPF and antioxidants as well as a new technology that we have developed, we can create sunscreens that protect skin from the sun’s rays and combat the appearance of dark spots at the same time.”

The water-resistant range of products provides broad-spectrum protection against the sun, and features ASP Technology (Anti-spot Protection). The collection includes Multi-Protection Sun Lotion for Face SPF 30; Multi-Protection Sun Lotion for Body SPF 30; and Multi-Protection Sun Spray (Oil-free) SPF 15.

According to the company, ASP Technology originally was developed to meet the needs of Asian customers who tend to gravitate toward skin care products that address hyperpigmentation, including dark spots. Researchers found that the ingredient melanase, found in ASP Technology, might have broader applications, and began looking at utilizing it in different skin care regimens. They found, says the company, that the technology helps minimize the appearance of dark spots and maximize the potential for a more even tan. When exposed to the sun, the skin’s natural defense mechanisms are activated and melanin is produced. Although melanin is necessary to protect the skin against excessive exposure to UVA and UVB, accelerated melanin production can lead to hyperpigmentation. ASP Technology acts as a UV-activated photosome, and actually helps break up the appearance of dark spots.

Using the same technology, Estée Lauder has launched Multi-Protection Sun Towelettes for Body SPF 15, which will be on counter in March 2007. Each individually packaged towelette is made from a soft non-woven fabric that absorbs and uniformly releases the lightweight SPF 15 formula onto the skin. It contains a water-resistant formula, plus glycerin and pantethine to guard against moisture loss, and antioxidant vitamins C and E to provide protection against the formation of future spots.

Clinique also has added to its Sun Care and Daily Sun Protection lines. Products that range from under-makeup use and lightweight daily protection to a high SPF moisturizing protection are among the latest. Clinique’s Super city Block Oil Free Daily Face Protector SPF 40 for women who want daily protection with a high SPF that provides a lightweight texture is one of the newest. A combination of titanium dioxide and ethylhexyl methoxycinnamate, provide broad-spectrum UVA and UVB protection.

Secrets from the Sea

While botanicals and vitamins are solidly positioned in the protection pantheon, there is a new crop of marine-based ingredients appearing in the market. Clinique’s Sun Care UV Response Face SPF 30 Sunscreen was developed to help protect facial skin from UV rays when sun exposure is intentional. The formula is said to address two types of sun damage—direct damage to skin cells and indirect damage from free radicals that are said to have a domino effect on the skin.

Plankton extract liposomes, according to the company, will provide repair technology to help address sun damage as it occurs, and photozomes will provide a second hit of time released antioxidant protection as the sun intensifies. Clinique scientists say that because plankton is exposed to extreme light during its lifespan, it has developed a natural resistance mechanism that allows it to use energy from sunlight to help repair damage. Clinique utilizes the ingredient in a liposome delivery system, so after just limited exposure to the sun, the sun-activated liposomes release the ingredient to help skin repair itself from direct sun damage as it occurs.

The formula contains a dual-action antioxidant defense system to help neutralize the damaging effects of free radicals and other environmental aggressors, and solar-activated photozomes release a second wave of antioxidant nordihydroguaiarectic acid, which is said to defend the skin against further assaults through a special liposome that is only activated when exposed to UV light. The result is that essential lipids in the skin are protected from oxidative damage, so there is less damage to the skin’s support system.

Even if understanding all the scientific nuances may not resonate for consumers, the consequences of venturing out into the sun with insufficient protection undoubtedly will. Sun damage clearly contributes to negative consequences for the skin, as well as overall health.

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