Innovations And Improvements In Sun Protection
2,829 viewsImproved research and manufacturing techniques have led to significant breakthroughs in sunscreens including better delivery systems and improved cosmetic elegance. These advances address some of the biggest issues surrounding sunscreen - UVA protection, proper application and frequency of reapplication.
“As the first independent organization to evaluate sunscreen efficacy through our Seal of Recommendation program in 1979, it’s rewarding to see the progress that has been made in sunscreens,” said Perry Robins, MD, President of The Skin Cancer Foundation. “Improved sun protection increases our chances of turning around the skin cancer epidemic in this country.”
Sunscreens are classified by the Food & Drug Administration (FDA) as over-the-counter drugs rather than cosmetics and are therefore reviewed and monitored by the FDA. The FDA monograph on sunscreen has been pending since 1999 and is currently still under review. The issues still to be resolved include the institution of a UVA assessment method, whether to cap sunscreens at SPF 30+, and sunscreen labeling.
New Ingredients Provide Better UVA Protection
Two significant sunscreen advancements have occurred in the past year - the introduction of improved, stabilized avobenzone, and the long-awaited FDA approval of another UVA-absorbing ingredient, MexorylTM SX. While avobenzone has long been one of the best UVA absorbers available, it has had to be combined with other ingredients (such as octocrylene and oxybenzone) to remain effective for any extended length of time. On its own, since it was not photostable, it broke down after a relatively short period when exposed to sunlight. However, a number of new patented technologies such as: HelioplexTM, Active Photo Barrier Complex,TM Dermaplex,TM, SunSureTM and AvoTriplexTM — have stabilized avobenzone, which protects further into the UVA range (peak absorption at 365 nm, protects up to 400 nanometers) than any other currently FDA-approved UVA absorber. MexorylTM SX, an ingredient just approved by the FDA this year, is a photostable UV filter which protects against the shorter UVA rays (peak absorption at 345 nm, protects up to 380 nanometers) and has been incorporated into some new moisturizers and sunscreen products.
These advancements are important because more and more research suggests that UVA exposure may be as damaging to the skin as UVB. Although scientists have known for several years that UVA penetrates more deeply into the skin than UVB, they believed that less of it was absorbed by DNA, causing fewer dangerous mutations. However an Australian-US study shows that UVA causes more genetic damage than UVB in skin cells where most skin cancers arise - the keratinocytes in the basal layer of the epidermis. UVB tends to cause damage in more superficial epidermal layers.
It is important to understand that an SPF rating mainly indicates relative protection from erythema (skin reddening) caused by the sun’s UVB (short-wave) rays. No sunscreen keeps out 100 percent of UVB, but applied properly, an SPF 15 filters out 93 percent of UVB, SPF 30 filters 97 percent and SPF 50 filters 98 percent. For adequate protection against both UVA and UVB, consumers should select a sunscreen that provides broad-spectrum protection (also known as multispectrum protection or UVA/UVB protection) - not just a sunscreen with a high SPF rating. The challenge is that currently no FDA- approved UVA measurement method exists in the US. A number of UVA assessment methods used abroad are being evaluated for use in the US, but in the meantime, the only way to be sure a product protects into the UVA range is by checking to see if one or more of the UVA-protective ingredients (avobenzone, oxybenzone, mexoryl, zinc oxide, titanium dioxide) is listed among its active ingredients.
Currently, 17 active ingredients are approved by the FDA for use in sunscreens in the United States. These fall into two broad categories: organic/chemical (absorbers) and inorganic/physical (blockers). Most UV filters are organic and protect by absorbing UV. They form a thin, protective film on the surface of the skin and absorb the UV radiation before it penetrates the skin. The inorganic sunscreens, titanium dioxide and zinc oxide, are insoluble particles which scatter, reflect and absorb UV; they were formerly known as “sunblocks,” but this nomenclature will be replaced with “inorganic” UV filters in the revised FDA Monograph. Today, many sunscreens contain a mixture of organic/chemical and inorganic/physical ingredients and have improved formulations and methods of application, making sunscreen use more appealing and cosmetically elegant.
Common FDA-approved active ingredients in sunscreen include:
- UVB organic/chemical (absorbers): Amino Benzoic Acid, Padimate O (Octyldimethyl PABA), Homosalate, Octisalate (Octyl salicylate), Octinoxate (Octyl methoxycinnamate or OCM), Octocrylene, Oxybenzone
- UVA organic/chemical (absorbers): Avobenzone, Mexoryl, Oxybenzone
- UVA/UVB inorganic/physical (formerly called blockers): Titanium Dioxide, Zinc Oxide
Improved Cosmetic Elegance and Delivery Systems Gone are the days when sunscreen was heavy and thick, felt sticky, and looked conspicuous and unattractive on the skin. Today, most lotions, creams and gels (as well as sprays) are lightweight in texture and easily absorbed, which often renders them undetectable. Fragrances are more appealing, and many companies offer fragrance-free formulations.
And, delivery systems have also improved. Once, the only way to apply sunscreen was to pour it from a tube or a bottle and spread it by hand. Now there are also several different types of sprays, wipes and sticks to choose from, depending upon your needs and personal preferences. For instance, someone on the go may want to start the day using a spray formulation, but then carry a stick with them for convenient reapplication, ideally every two hours. Most daily moisturizers and many cosmetics now contain SPF 15+ sunscreen as well, providing another easy, convenient way to incorporate sun protection into your daily routine.
Sunscreen Labeling
A sunscreen is considered water-resistant if the SPF level is determined to remain effective after 40 minutes of water immersion. The testing procedure for these sunscreens is as follows: The subjects must be immersed in whirlpool for 20 minutes followed by air-drying the skin. The procedure is repeated once (ie, another 20 minutes immersion, followed by air-drying the skin). The SPF is then measured after the total 40 minutes of water contact. Sunscreens that are labeled very water-resistant must retain an effective SPF after undergoing the same procedure for a total of 80 minutes (four 20-minute immersions and drying of the skin).
It is important to note that the FDA has proposed that the term “waterproof” will no longer be allowed in labeling, since no sunscreen is completely waterproof; the term “water resistant” and “very water resistant” will be used instead. Nor will the term “sunblock” be permitted, as it can mislead people into believing that total sun protection is achieved by using these products. For people who are going to be outdoors for a prolonged period of time, opt for a water-resistant or very water resistant sunscreen formulation.
The Importance of Proper Application
Even with all their recent improvements, sunscreen can only be effective if applied correctly and frequently enough. In actual use, most people do not apply the same amount that is used in testing (2 mg/cm2). To adequately apply sunscreen to the entire body surface, The Skin Cancer Foundation recommends applying at least 1 ounce (two tablespoons), the same amount used in testing, to exposed areas 30 minutes before sun exposure, and reapplying it every two hours or immediately after excessive sweating or swimming.
The Sunscreen Short List
As complicated as the subject of sunscreens may seem, there are really four key points to remember:
- For proper UVB protection, use an SPF 15 or higher sunscreen every day.
- For effective UVA protection, select products that contain some combination of avobenzone, oxybenzone, mexoryl, zinc oxide and titanium dioxide.
- When applying sunscreen to the entire body, use one ounce (two tablespoons) of sunscreen.
- Reapply every two hours or immediately after swimming or excessive sweating.
In reality, no matter what sunscreen you use, some UV still gets through to the skin. That is why the Foundation considers sunscreen one vital part of a comprehensive sun protection program, along with seeking the shade between 10 a.m. and 4 p.m. and wearing sun-protective clothing, including a wide-brimmed hat and UV-blocking sunglasses.
Based on an SkinCancer.org Foundation.