32 ANTI-POLLUTION A SPF30 ■ SPF30 +2% Active Ingredient ■
35 30 25 20 15 10 5 0
20 *** ** * 10 5 0 **** **** **** **** 15
+60% ****
+48% ****
B Sunscreen ■ Sunscreen +2% Active Ingredient ■
**** +85%
Figure 2: UVA protection in vitro testing of the active ingredient in formulation. The tests were carried out in a sun simulator at 765 W/m2
While on fairer skins (Phototypes I and II), the risk of skin damage and sunburn due to the exposure to sunlight is greater than for darker skin tones. For this study, the Individual Typology Angle
(ITA°) was considered. ITA° describes the degree of pigmentation and it correlates to the skin type. Values of ITA° equal or higher than 50°
correspond to phototype I that have the lighter skin, while values below -50° correspond to phototype VI for the darkest skin. Phototype III-IV correlates to ITA° values of between -25° and 25°. The subjects were asked to use a provided
SPF30 formula containing the active ingredient on one half of the face and the same formula without the ingredient on the other half and being exposed daily to sunlight for at least two hours for the duration of the study. The SPF30 base formula contained UVB
filters to avoid the volunteers from getting sunburn. The ITA° was measured at days 7, 14 and 21 and compared to the values on day 0. The increment of ITA° (ΔITA°) of the two halves versus day 0 was contrasted to quantify the difference in colouration (Figure 3). After three weeks of study, there was a clear
A B
3 2 1
0 -1 -2 -3
Day 7 Day 14 Day 21 Figure 3: A: Volunteer after 21 days of study. B: ΔITA° at 7, 14 and 21 days respect to the values at day 0 PERSONAL CARE July 2024
SPF30 ■ SPF30 +2% Active Ingredient ■ *
p=0.089 p=0.057 p=0.033
tendency. While the half of the face that had not been treated with the active showed a linear decrease of the ΔITA°; the increment of the Individual Typology Angle of the other half remained constant for the three weeks. In other words, the skin with the active ingredient did not darken, but the skin without did. This exhaustive study proved that the
active ingredient prevents UVA from reaching the dermis and triggering the pigmentation mechanisms under real sun exposure conditions. The results show that it is highly efficient on medium to dark skin tones (Phototypes III-IV) and suggest that it could be as effective for lighter and darker skins.
Skin photoageing UVA-radiation being one of the causes of skin ageing is well-established.4
On a renowned
piece by Jennifer Gordon and Joaquin C. Brieva published on The New-England Medical Review, they showed the effect of long-term exposure to UVA rays on the skin.5 Trucker William McElligot had been driving for over 25 years, getting more exposed to sunlight
. A: UVA-PF
performance of a commercial SPF30 sunscreen against a SPF30 formula containing 2% of the active ingredient.B: UVA-PF performance of SPF30 with 2% of the active ingredient against the placebo formula.
on one side. The consequences are evident with the left-side of his face showing more wrinkles, thickening and other signs of skin ageing. Unfortunately, there is not only one mechanism related to skin photoageing, albeit they are mostly related to the increase of oxidative stress. UVA-rays can activate different pathways that lead to skin ageing, being all interconnected. There are markers for these mechanisms
that can show the capacity of an ingredient to protect from skin ageing. The capacity of the active ingredient against UVA-induced skin ageing was evaluated against four specific markers: the formation of Reactive Oxygen Species, the damage of the mitochondrial DNA, the activation of collagenase-1 and the expression of Interleukin-6.
Impeding the UVA-induced formation of ROS When UVA reaches the dermis, it can form reactive oxygen species (ROS). These trigger a chain reaction further breaking other bonds which can result in mitochondrial DNA damage among other skin degradation mechanisms.6 Avoiding the formation of ROS can, therefore, prevent skin ageing. In an in vitro study, the capacity of the active
to avoid the generation of ROS by UVA was evaluated on normal human dermal fibroblasts (NHDF). A formula containing the ingredient in 2% was spread over Polymethyl methacrylate (PMMA) plates which, then, were submitted to sun-like light for the activation of the precursor. The NHDF-containing wells were covered
with the pre-activated plates and submitted under UVA light. Cells covered with aluminium foil were considered the positive control, while cells with the active without UVB activation were considered the negative control. The results show that just after 12 minutes of
pre-activation, the cells show a 14% less of ROS formation (Figure 4A). With one hour of pre- activation, there is 33% less which is equivalent
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UVA-PF
ITA increment vs day 0 (ΔITA°)
UVA-PF
0h 0.25h
0.5h 1h 1.5h 2h 3h 4h 5h 6h
0 min 15 min 30 min 60 min 90 min 120 min
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