Ready for a good and conscious suntan? Let’s know better sunscreens…

solariA wonderful sunny day could really change our mood, it allows us to better face daily routine and enjoy the outdoor benefits. A sunny day brings us back to positive thinking, energy, beauty and health. However, we should not forget all the implications of sun-exposure, in order to benefit from sunlight avoiding the related risks, caused by solar over-exposure. Let’s better understand what sun exposure really implicates, knowing that uneven solar exposure can cause not only tiny sunburns, but also it could increase incidence of certain forms of skin cancer.

Sunlight is composed by different bands characterized by their wavelenght (λ) and energy: a portion of such radiation is represented by ultraviolet (UV) rays

  • UVC rays (λ = 40 ÷ 286 nm) are filtered off by atmosphere ozone and they don’t reach Earth surface in considerable amount.
  • UVB rays (λ = 286 ÷ 320 nm) stimulate melanin formation even though they penetrate only partially through skin, and are the main responsible for suntanning. They act superficially on epidermis and can damage skin cells, determining inflammation and sunburns, due to their high energy.
  • UVA rays (λ = 320 ÷ 400 nm) represent the majority of UV radiation,  they deeply penetrate through skin and cause damage to underlying tissues, they provoke skin ageing  and contribute to pathologic phenomena. They also give rapid suntan using the already-formed melanin.

Cosmetic sunscreens play a major role in skin safety, they represent a strong defence for our skin and contribute to effectively protect it from sunlight. Since September 2006 European Commission has set directives for a perfect solar protection formulation: it must screen efficaciously from both UVA and UVB rays. EU directives compel cosmetic manufactures to display clear labels in terms of efficacy and claims of sun-care products. BeC, as a cosmetic manufacturer, has been working seriously to assure the best performance of sun-care products, with the added value of the  essential oils, the emollient, soothing and antioxidant actives that play a key role for comprehensive sun protection. They sooth erythema, while blocking skin photo-aging, beside cutting off UV rays.

Let’s better know which sunscreen are allowed in EU in cosmetics, according the Regulation (EC)   No   1223/2009   of    the   European   Parliament and of the Council of Europe:

  1. para-aminobenzoic (PABA) acid derivatives screen UVB rays with absorbance maximum peaks between 285 and 310 nm.
  2. Cinnamates (e. ethylhexyl methoxycinnamate) are able to protect from UVB rays behaving also as quencher of excited species produced by solar radiation. They absorb radiation at maximum wavelength around 310 nm.
  3. Benzylidencamphor derivatives screen UVB rays and are quencher as well.
  4. Dibenzoylmethane derivatives protect from UVA rays.
  5. Benzophenones absorb both UVA and UVB rays.
  6. Salicilates boast a moderate absorbing efficacy in UVB region, with absorbance maximum at around 305 nm.
  7. Triazines, i.e. Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, are excellent photo-stable sunscreen covering the wide range of UVA and UVB.
  8. Diphenylcyanoacrilates, i.e. Octocrylene represent a good wide range UVA-UVB sunscreen.
  9. Titanium bioxide and Zinc oxide represent physical sunscreen characterized by full UV-range coverage and reflecting action with sunlight scattering properties.

BeC sun-care products are based on a careful combination of the best photo-stable suncreens (physical and chemical) in order to assure complete coverage of the UV spectrum.

The special formulation and the efficacy testing on human volunteers assure a totally safe and perfect suntan. To this aim, the sunscreen of Creme solari (SPF 6, 15 , 30 e 50+) covers the full protection range so to perfectly match your specific photo-type. Special attention is devoted to deliver super-fine and even dispersion of the UV-filter in the formula, so to assure a uniform protection and suntan. Ingredients’ quality, mostly from natural origin (100% natural in case of SPF6) makes these products fully skin-compatible, suitable also for the most delicate skin-types.

As we anticipated, BeC sun care products are not only made of sunscreens! Along with natural components which stimulate melanogenesis (ATP, tyrosine and riboflavine – vit. B2), making suntan more rapid and intense, i.e. aiding skin self-protect, BeC sun care products are rich of hydrating and soothing actives, which nourish our skin and contribute to re-equilibrate physiologic skin moisture and elasticity. Daily use of BeC suncare products avoid damages caused by sun over-exposure but also effectively increase hydration and elasticity!
Natural Vitamin E contained in every BeC sun care product helps prevent wrinkle formation and premature skin ageing along with defending skin from the action of free radicals involved in radiation mediated inflammatory processes. BeC sun care line acts by preventing sun damages: this is especially the case for the oil Huile SolÈ® that is particularly rich in vitamin E. Efficacy tests have shown that daily use reduces already formed wrinkles by 12% in only one week of treatment! This is an outstanding result!!!

BeC sun care products are designed to let us enjoy full benefits from sunlight, while reducing risks and side effects such as allergies, photo-sensitization and skin ageing. In order to protect skin from harmful radiation, our careful sun care formulation stimulates natural skin defence and guarantees a perfect and uniform suntan leaving hydrated, elastic and silky skin. The soothing action on irritation and the prevention of risks associated to free radicals – that causes premature ageing – complete the special properties of our sun care line.

Let’s benefit from a good suntan without turning down an excellent solar protection!

Skin damage caused by “wrong” sunscreens: the photosensitization phenomenon

 creme solari becAs we have seen in the previous post, many sunscreens get damaged by sun radiation as they absorb it. The modest photo-stability of such sunscreens has important consequences on the safety and efficacy of sun-care products based on them. In the previous discussion we have seen that photo-instability of sunscreens causes a reduction of sun protection factor (SPF) with time. There are, however, additional interactions of sunscreens with sunlight that have even worse consequences on their safety. We will discuss them in this article.
Solar radiation contains sufficient energy to damage some molecules (M), including some molecules found in our skin, as exemplified in the equation:

M + light→ fragment-A + fragment-B

Fragments indicated as A and B, in the example above, are often free radicals that can attack other molecules, damaging or modifying them. For instance, if such a reaction occurred in our skin, damage could occur to structural proteins like collagen and elastin, contributing to the formation of wrinkles and the onsetting of photo-aging. Furthermore, it could start chain-reactions leading to erythema, other inflammatory states and even genetic mutations (skin cancer). Products containing sunscreens are meant to protect skin from all such damages, and normally they do, by decreasing the amount of UV radiation that hits our skin, i.e. acting as “filters”. But CAUTION !!! Not all the sunscreens are friends of our skin, and actually some might cause bigger damage than that they are expected to prevent. How?
Let’s go back to our previous example. In order for M to react with light, it is necessary that molecule M is at least able to absorb the light at quantum level, i.e. it is necessary the energy carried by light photons hitting M corresponds exactly to the energy gap between quantum levels in the molecule. Often this is not the case and molecule M would be perfectly “safe” if it was not for the presence of other molecules called photosensitizers.

benzofenone

Benzophenone and main benzophenone derivatives used as sunscreen in sun-care cosmetic products as well as in the protection of manufacts. The common base structure is drawn in blue

F + light F*  

then…

F* + M F + fragment-A + fragment-B

This process is well known in photochemistry and benzophenone is among the photosensitizers of broader use in industrial processes to induce photochemical reactions. Benzophenone is also the lead structure for many and, unfortunately, very popular sunscreens, widely used in sun-care cosmetics to give sun protection factor. Most common examples are depicted in the figure above. Sunscreens like benzophenone-3 and benzophenone-4 are structurally related to benzophenone and are potent photosensitizers. In case M is a biomolecule in our skin, such as collagen, elastin, an enzyme or DNA, this can be damages by exposure to sunlight in the presence of photosensitizers (like benzophenone derivatives) much more it would happen in their absence. In other words, certain sunscreens can amplify the damage to our skin caused by sunlight.

Many benzophenone derivatives are available today and 12 of them are of common use.  Those more commonly used in the manufacture of sun-care cosmetics and other goods, are listed in the following:

Benzophenone-1: 2,4-Dihydroxybenzophenone
Benzoophenone-2: 2,2′,4,4′-Tetrahydroxybenzophenone
Benzophenone-3 (or oxybenzone): 2-Hydroxy-4-methoxybenzophenone
Benzophenone-4 (or sulisbenzone): 2-Hydroxy-4-methoxy-benzophenone-5-sulphonic acid
Benzophenone-5 (the sodium salt of sulisbenzone): Benzenesulfonic acid, 5-benzoyl-4-hydroxy-2-methoxy-, monosodium salt
Benzophenone-8 (or dioxybenzone): 2-Hydroxy-4-methoxyphenyl)-(2-hydroxyphenyl)methanone
Benzophenone-10 (or mexenone): 2-hydroxy-4-methoxy-4′-methyl-benzophenone
Benzophenone-11: it is a mixture of benzophenone 2 e 6.

For these reasons BeC does not use benzophenone derivatives in sun-care products !!! BeC uses only physical filters in low protection products and, in high protection products, we use a combination of physical filters and new generation chemical filters, which are highly photostable. Here you can find more info on BeC sun-care products.

Therefore, when we chose a sun-care product, it is very important we pay attention to the label and read the composition: don’t look at the SPF value only!

We often hear that we should not expose to sunlight after having used perfumes or other products, as they can give photosensitization problems. The typical recommendation is to use only sunscreen products, but caution should be paid when we choose the sunscreen product, as even sunscreens can cause the same problems. Therefore, even if you have no particular problem of sensitivity to sunlight and think that any product will do the job, think again and don’t overlook the importance of choosing high quality sunscreens, so to make sure that the problems you don’t have will not be caused by the wrong product.

Photo-degradation of sunscreens and skin damaging

soleWe have previously discussed the mechanism of action of sunscreens, underlining that chemical sunscreens absorb the energy of sunlight and subsequently re-emit it in the form of heat, possibly without any alteration in the structure of the sunscreen itself. Possibly… does it always go this way? Unfortunately it doesn’t. For this reason we wish to discuss here a bit more on the photostability of sunscreens. Although this aspect is often overlooked (guess why?), it has major consequences on our health.
After having absorbed sunlight energy, chemical sunscreens are in a higher quantum energy state, from which they can undergo one of three processes:

  1.    they can go back to the lower energy state by loosing energy in the form of heat (which is often not perceived by our senses), thereby making ready to start over again and absorb more solar energy;
  2.     they can release the excess energy by breaking their structure into fragments, i.e. they degrade and form free radicals or use the energy to react with other molecules (photochemical reactions);
  3.     they can transfer the excess energy to another molecule by “hitting it”, i.e. they behave as photo-sensitizers.

Ideally, sunscreens should use only the first route; however, not all the sunscreens are identical and some of them, which are less stable than others, after several absorption-emission cycles, may take the second route (we will discuss in a following post of those sunscreens that take the third route and act as photosensitizers).
If the sunscreen degrades, it most commonly produces free radicals and other dangerous species. If the sunscreen has been absorbed deeply into our skin, those free radicals can attack and damage proteins and DNA, accelerating the photo-aging processes of the skin. In high quality formulations such damages can be prevented by the abundant presence of antioxidants (e.g. vitamin E) in the formula, so to block free radicals before they can cause any damage. Therefore, it is very important to always choose high quality products after careful reading of their label.
There is, however, another point to take into account: as the sunscreen degrades the solar protection factor (SPF) of the product progressively decreases. And antioxidants cannot help in this reguard.

photo-degradation_EN

Variation of the UV-Vis absorption spectra of two examples of sunscreen formulation, after exposure of the formulation to the same “dose” of sunlight (UV irradiation). The upper graph refers to a formulation with NON photostable sunscreens, which evidently shows a reduction of the spectrum after UV exposure, meaning a marked decrease in the SPF. The lower graph, instead, shows the behavior of a (BeC) formulation with photostable sunscreens: only negligible variation of the spectrum is displayed after irradiation implying no loss of SPF and more durable performance.

The fact that a sunscreen formula looses its SPF on exposing to sunlight depends on the phostability of the sunscreens: with highly photostable sunscreens the phenomenon has negligible relevance; however, with little photostable sunscreen molecules, which are unfortunately the most common in commercial formulas, the phenomenon is very relevant, as illustrated in the graphs on the left, displaying the comparison between two real formulations: a famous commercial products (don’t ask which one) and BeC sunscreen SPF15 cream.
Many of us think that “waterproof” sunscreen formulas – which can resist for several minutes of swimming in seawater – would provide a safer protection for the entire day, since the product would not be washed away. A look at the graphs clearly tells that this is not the case: a waterproof sunscreen formula does not guarantee safer daylong protection. First of all, we should consider whether the sunscreen contained in the formula is photostable!!! Secondly, we should consider that, even if the sunscreen is photostable, during a typical day at the seaside, we dry ourselves with a towel; we roll up in the sand, which we clean up by rubbing or washing our skin; we sweat in the heat or during physical activity (e.g. beach sports). All such actions end up removing the sunscreen form our skin anyway. Therefore, a high quality sunscreen formula, based on photostable components, is the ideal choice for a safer protection, but we should not forget that it is wise to re-apply the product several times during the day, particularly in the case of children.