Global state of sunscreens
SUMMARY
摘要
英文原文
The use of sunscreen is embedded in a hierarchy of sun protection strategies consisting primarily of sun avoidance by seeking shade and covering up with clothing. Sunscreens are, however, important means of protection; thus, understanding how they work and knowing their limitations are crucial. This review explains the role of ultraviolet (UV) filters, emollients, emulsifier systems and other components in a sunscreen, as well as trends in formula- tions in Europe, North America, Latin America, and Asia Pacific. Further- more, it explains how sunscreen performance in terms of sun protection factor, UVA protection, and other metrics can be simulated. The role of sensory characteristics in assessing and improving compliance is also dis- cussed. In the final chapter, Facts and Fiction, five of the most common myths about sun exposure and sun protection by sunscreen are debunked.
对应中文
防晒霜的使用是一系列结构性防晒策略中的一环，这些策略中最重要的是寻找阴凉处或用衣服遮盖来躲避阳光。然而，防晒霜也是重要的保护手段；因此，了解它们是如何起作用的、并知道它们的局限性至关重要。这篇综述解释了紫外线（UV）过滤成分、润肤剂、乳化剂系统和其他成分在防晒霜中的作用，以及欧洲、北美、拉丁美洲和亚太地区配方的发展趋势。此外，还解释了如何从防晒因子、UVA防护和其他指标来模拟防晒霜的性能。文中还讨论了人感官特征在评估和提高依从性方面的作用。在最后一章“事实与虚构”中，揭穿了五个最常见的关于防晒霜暴露和防晒的“神话传说”。
英文原文
Sunscreens should protect against sunburn, skin photo, and skin cancer during the entire time of sun exposure. We assessed the status as well as open questions of current sunscreens, and discuss what still has to be improved. We identified four requirements for good UV protection.
对应中文
慢性防晒霜应该能够在整个日照时间内防止晒伤、光老化和皮肤癌。我们评估了当前防晒霜的现状以及存在的问题，讨论了还有哪些需要改进的地方，并确定了良好紫外线防护的四个要求。
英文原文
First, sunscreen technology: the ideal protection profile is uniform protection across the entire UVB/UVA range (290–400 nm), similar to protection provided by sun avoidance and covering up by textiles. In silico experiments show how well this can be achieved nowadays by combining UVB, broad-spectrum and UVA filters. With the help of particulate UV filters, sunscreens can protect at the border of UVA-I and up to the short visible light beyond 400 nm .
对应中文
首先，防晒技术：理想的防护模式是在整个UVB/UVA范围（290-400nm）内提供均匀的防护，类似于防晒和纺织品遮盖所提供的防护。如今，通过结合UVB、广谱和UVA滤波器可以很好地实现这一点。在微粒紫外线过滤器的帮助下，防晒霜可以保护UVA-I边界和至400nm的短可见光。
英文原文
Second, the assessment of the sunscreen performance is crucial. The sun protection factor (SPF) is the well- established metric for sunscreen protection against ery- thema caused by solar-simulated sunlight, but is not sufficient if used alone to serve also as a metric for pro- tection against photoaging and skin cancer. For these types of damage beyond sunburn, protection against UVA radiation has also to be assessed. It has now been recognized that there is no need for an extra in vivo UVA measurement besides the SPF, and the available in vitro UVA methods are well on their way to being harmonized.
对应中文
其次，防晒霜性能的评估至关重要。防晒系数（SPF）是一个公认的防晒指标，用于防止由模拟太阳光引起的太阳辐射，但如果单独使用，还不足以作为防止光老化和皮肤癌的指标。对于晒伤以外的这类损伤，还需要评估对UVA辐射的防护。现在人们已经认识到，除SPF检测以外不需要单独再进行活体UVA测量，可用的体外UVA测量方法正朝着统一的方向发展。
英文原文
ChronicThird, performance criteria and standards are also crucial for good UV protection. Assessment of UVA pro- tection should be related to the SPF as the major claim on sunscreens, as recommended by the European commis- sion, stating that UVA-PF/SPF ≥ 1/3. Other UVA catego- ries such as the Boots 5-star rating with a UVA/UVB ratio > 0.9 go beyond the EU recommendation and are thus closer to uniform UVB/UVA protection, which may be regarded as an ideal sunscreen performance. UV such.
对应中文
第三，性能标准和标准对于良好的紫外线防护也是必要的。根据欧洲委员会的建议，UVA防护评估应主要与SPF相关，应该达到UVA-PF/SPF≥1/3。其他UVA防护标准类别，如Boots五星评分UVA/UVB比率>0.9的，都超出了欧盟的建议，因此更接近于统一的UVB/UVA防护，这可能被视为理想的防晒性能。
英文原文
Fourth, compliance is the ‘conditio sine qua non’ of any good sun protection. Major deviations, besides not applying any sunscreen at all, are non-uniform applica- tion and inadequate amounts applied, which may vary between 0.5 and 2 mg/cm2. Compliance is most positively influenced by the development of cosmetically elegant and pleasing formulations. As development objective, this should thus rank as high as achieving a certain protection profile or fitting into a certain standard SPF or UVA category.
对应中文
第四，合规是任何良好防晒的“先决条件”。除了完全不涂防晒霜外，主要的偏差是涂抹不均匀和涂抹量不足，可能在0.5到2mg/cm²之间变化。化妆品配方的讲究和舒适性对使用者依从性的影响最大。因此，作为发展目标，这应该与实现一定的防护效果或符合某种SPF标准或UVA类别一样重要。
英文原文
Fulfilling the four requirements just discussed should lead to sunscreens becoming a more reliable means of sun protection, similar to sun avoidance and covering up by textiles. This review will touch on all four of these aspects after an introduction that explains how sunscreens work. In the final part, facts and fiction, the gathered knowledge is applied to debunk five of the most common myths about sunscreens.
对应中文
满足刚才讨论的四个要求应该会使防晒霜成为一种更可靠的防晒手段，类似于用纺织品来防晒和遮盖。在介绍了防晒霜的工作原理之后，这篇综述将涉及到这四个方面。在最后一部分，事实和虚构，收集到的知识被用来揭穿关于防晒霜的五个最常见的神话。
TECHNOLOGY OF UV FILTERS AND REGULATORY
紫外线滤光器及其调节技术
Properties of UV filters for sunscreens
防晒霜用紫外线滤光器的性能
英文原文
The basic requirements for all UV filters that are used in sunscreens are: 1) efficacy, 2) safety, 3) registration, and freedom-to-operate with respect to the status of intellec- tual property. The development of efficient molecules is the prerequisite before other aspects come into play. Efficacy means, first of all, that there is good absorbance in the spectral range of most interest for sunscreens, 290– 400 nm. It also means that it is possible to incorporate the substance in sufficient amounts into cosmetic formu- lations. UV filters may be dissolved in the oil phase or the water phase of sunscreen formulations and thus the respective solubility must be high enough. Another pos- sibility is to use dispersions of fine particles of the absorb- ing substances. In all countries, new UV filters require premarketing approval. With the help of an extensive toxi- cological testing program including in vivo tests on animals, new UV filters must be shown to be safe. So far, the European scientific opinion on safety, issued by the Scientific Committee for Consumer Safety, has been the benchmark for most countries in the world. This may change in the future due to the animal test ban for all cosmetic ingredients in Europe since March 2013.
对应中文
用于防晒霜的所有紫外线过滤器的基本要求是：1)有效性，2)安全性，3)注册，和知识产权的自主所有。有效分子的开发是其他作用发挥的前提，首先，有效意味着在防晒霜最主要的290-400nm的光谱范围内有良好的吸光度。这也意味着有可能将足量的物质掺入化妆品配方中。紫外线过滤器可溶解在防晒霜配方的油相或水相中，因此相应的溶解度必须足够高。另一种可能性是使用吸附物质的细小颗粒的分散体。在所有国家，新的紫外线过滤器都需要上市前的批准。在广泛的毒理学测试计划的帮助下，包括在动物身上的活体测试，新的紫外线过滤器必须证明是安全的。到目前为止，由消费者安全科学委员会发布的欧洲安全科学意见已经成为世界上大多数国家的基准。由于欧洲自2013年3月起禁止对所有化妆品成分进行动物试验，这种情况未来可能会改变。
Chemistry of organic UV absorbers
有机紫外线吸收剂化学
英文原文
Prerequisites of organic molecules for the absorption of UV radiation, photophysical processes which may occur after the absorption of a UV photon, as well as possible photochemical reactions are discussed in detail in Herzog. At present, all organic UV absorbers used in sun- screens possess aromatic moieties. The substitutions at the aromatic ring are of great importance for the UV spectroscopic properties. An increase in the number of resonance structures stabilizes the excited state, thus leading to stronger absorption at longer wavelengths. For that reason, mono-substituted aromatics, both with resonance-driven electron releasing (+M) or electron withdrawing (−M) substituents, show shifts toward longer wavelengths, also known as bathochromic shifts, and increased absorption intensities. Most efficient are di-substituted systems with a +M- and a −M-group in para-position, so-called push–pull systems. Figure 3 shows a comparison of a push–pull system, ethylhexyl dimethyl para-aminobenzoate (ED-PABA), and a UV absorber with similar groups but in ortho-position, menthyl anthranilate (MA). As expected, the absorption intensity of ED-PABA is significantly stronger than that of MA. The bathochromic shift observed with MA can be explained by the hydrogen bond that is formed between one of the hydrogen atoms of the amino-group and the oxygen of the ester bond. E11 is the specific extinction that would be shown by the extinction of a 1% (w/v) solution at an optical thickness of 1 cm.
对应中文
在Herzog中详细讨论了有机分子吸收UV辐射的前提条件，吸收UV光子后可能发生的光物理过程，以及可能的光化学反应。目前，所有用于防晒霜的有机紫外线吸收剂都含有芳香族成分。芳香环上的取代对紫外光谱性质有重要影响。随着共振结构数量的增加，激发态趋于稳定，从而在较长波长处产生更强的吸收。因此，单取代芳烃，既有共振驱动的电子释放(+M)，也有电子抽离(−M)取代基，表现为向更长的波长移动，也称为红移，并增加吸收强度。最有效的是具有并列位置的+M-和−M-群的双取代系统，即所谓的推拉系统。（文中）图3显示了推拉系统，对氨基苯甲酸二甲基乙基己酯（ED-PABA）和具有类似基团但在邻位的邻氨基苯甲酸薄荷酯（MA）的紫外线吸收剂的比较。正如预期的那样，ED-PABA的吸收强度明显强于MA。用MA观察到的深色位移可以用氨基上的一个氢原子与酯键上的氧之间形成的氢键来解释。E11是由光学厚度为1 cm的A1%(w/v)溶液的消光表示的特定消光。。
Inorganic particulate UV filters
无机微粒紫外线滤光器
英文原文
TiO2 and ZnO are the only inorganic materials which so far are allowed for the use as UV filters in sunscreens. In order to be efficacious and nonwhitening on the skin, the particles of these rather insoluble substances have to be very small, typically in the size range around 100 nm or below. Thus, the grades of these inorganic oxides employed in sunscreens attenuate UV mainly by absorption, superimposed by some scatter- ing. Being small particulate crystals, these materials are semiconductors with high band gap energy between the valence and the conduction band. The band gap of the bulk crystals is in the range of an energy corresponding to wavelengths between 380 and 420 nm. In the case of TiO2, it alters with the size of the primary particles, that is, the smaller the primary particles, the higher the band gap energy. UV radiation is absorbed by elevating an elec- tron from the valence to the conduction band. Light at or below this wavelength will have enough energy to excite electrons from the valence band to the conduction band. Any photon with a wavelength longer than the band gap will not be absorbed by the sunscreen. The resulting elec- tron hole can be refilled by electrons from the surrounding materials, thus leading to oxidation reactions, also known as photocatalytic effect. To prevent this effect, TiO2 for sunscreen applications is coated with Al2O3 or SiO2. Further, in most grades for sunscreens the rutile crystal modification is employed, which shows a lower tendency for photocatalysis than anatase type. The inorganic parti- cles as such are water- dispersible, but may be rendered oil dispersible by adding organic coatings.
对应中文
二氧化钛和氧化锌是目前唯一被允许用作防晒霜紫外线过滤器的无机材料。为了对皮肤有效且不泛白，这些极难溶解的物质的颗粒必须非常小，通常在100 nm或以下的大小范围内。因此，防晒霜中使用的这些无机氧化物的等级主要是通过吸收，再加上一些散射来衰减紫外线。作为小颗粒晶体，这些材料是在化学价和导带之间具有高带隙能量的半导体。大块晶体的带隙在波长380到420nm之间的能量范围内。在二氧化钛的情况下，它会随着初级粒子的大小而变化，也就是说，初级粒子越小，带隙能量越高。紫外线辐射是通过将电子从价带提升到导带来吸收的。这个波长或以下的光将有足够的能量将电子从价带激发到导带。任何波长大于带隙的光子都不会被防晒霜吸收。由此产生的电子空穴可以被周围材料中的电子重新填充，从而导致氧化反应，也就是光催化效应。为了防止这种影响，用于防晒应用的二氧化钛涂有氧化铝或二氧化硅。此外，在大多数等级的防晒霜中，采用金红石晶体改性，这显示出比锐钛矿型更低的光催化倾向。无机颗粒本身是水分散的，但可通过添加有机涂层使其具有油分散性。
Organic particulate UV filters
有机微粒紫外线滤光器
英文原文
Limited solubility of organic UV filters in the water phase or, predominantly, in the oil phase of sunscreen formula- tions may cause severe formulation difficulties. For this reason, the concept of particulate organic UV filters was developed, circumventing the problem of limited solubil- ity. UV filters that are nearly insoluble in oil and in water can be prepared in the form of small particles in an aqueous phase, employing milling processes. The first example for this approach was realized with methylene bis-benzotriazolyl tetramethyl-butylphenol (MBBT). The pure substance is a solid (Tm = 195°C), the particle size of the powder ranging between 40 and 150 μm. First, aqueous slurry containing 50% (w/w) of the active agent and 7.5% (w/w) of decyl glucoside as dispersing agent is prepared. After a wet-milling procedure, an average parti- cle size of 0.16 μm is obtained. It was shown that the spe- cific extinction of the particulate UV absorber increases with decreasing particle size. Thus, the small particle size is necessary to obtain an efficient product. The specific extinction comes close to the specific extinction of the UV absorber in solution.
对应中文
有机紫外线滤光器在防晒配方乳液的水相或油相中的溶解度有限，可能会导致严重的配方困难。因此，提出了微粒有机紫外滤光片的概念，避免了溶解度有限的问题。几乎不溶于油和水的紫外滤光片可以采用研磨工艺以水相中的小颗粒的形式制备。该方法的第一个实例是以亚甲基双苯并三唑基四甲基丁基苯酚(MBBT)为例，纯物质为固体(Tm=195°C)，粉末粒度在40~150μm之间。首先制备含50%(w/w)活化剂和7.5%(w/w)癸基葡萄糖苷的水悬浮液。经过湿法球磨，得到平均粒径为0.16μm的颗粒。结果表明，随着粒径的减小，颗粒紫外吸收剂的特定消光率增大。因此，要获得高效的产品，必须要有较小的颗粒尺寸。比消光接近于溶液中紫外线吸收体的比消光。
英文原文
The UV absorbance spectrum of particulate MBBT has a different shape than that of MBBT dissolved in dioxane. The most distinctive features of the particle spec- trum are the shift of the UVA maximum to 360 nm and an additional shoulder around 380 nm caused by intermo- lecular interactions of the π-electrons inside the particles. Due to the shoulder at 380 nm, this filter covers a very broad range of the UV radiation. Similar to small inorganic particle UV filters, the contribution to protection by scat- tering or reflectance is 5% or less.
对应中文
微粒MBBT的紫外吸收光谱与溶解在二氧六环中的MBBT的紫外吸收光谱形状不同。粒子光谱最显著的特征是，由于粒子内部π-电子的分子间相互作用，UVA最大值移动到360nm，并在380nm附近产生一个附加的肩部。由于肩部位于380nm，该滤光片覆盖了所有范围的紫外线辐射。与小型无机粒子紫外线滤光片类似，散射或反射对保护的贡献为5%或更小。
Sunscreen formats
防晒霜形式
英文原文
Among the high diversity of formats available on the market, the standard types, lotions, and creams/gel-creams still remain the preferred form with approximately 60% of the most recently intro- duced market products irrespective of the region. However, notable differences appeared around the globe in preferences for different types of products.
对应中文
在市场上可提供的高多样性配方中，不论地区如何，标准型、乳液和面霜/凝胶面霜仍然是首选配方、占比最近推出的市场产品中的60%。但是，全球各地对不同类型产品的偏好仍然存在显著差异。
英文原文
In Europe, emulsion sprays remain very popular; although, other forms such as sticks, oils, mousses, and powders represent almost 16% of the launched products in contrast to the three other regions where these formats remain marginal.
对应中文
在欧洲，乳液喷雾仍然非常流行；尽管如此，其他形式如棒型、油、摩丝、粉末占所有产品的16%，而在其他三个地区、以上产品仍处于边缘地位的区域。
英文原文
‘Shake well’ formats are especially popular in AP, accounting for 22% of the products launched there com- pared with only 2% in the three other regions. These gen- erally consist in a very fluid water-in-silicone formulation, which provides an exceptional light and silky skin feel. They contain a high amount of volatile silicones that enable a high spreading during application, a fast absorp- tion of the product after application on skin, and a final silky skin feel. The bottle generally contains a small ball to shake the formulation before use, to ensure its macro- scopic homogeneity. Several years ago, such products also entered the European market, where they were associated with pocket sun protection but now only represent about 2.5% of recently launched products. Light gel-cream for- mulations with aqua-like touch have become popular of late in AP and have won market share from water silicone systems.
对应中文
“混摇”形式在亚太地区尤其流行，占亚太地区推出产品的22%，而其他三个地区仅占2%。这些产品通常包含在一种流动性能好的硅树脂配方中，提供了一种非常轻盈和丝滑的皮肤感觉。它们含有大量的挥发性硅酮，产品在使用过程中能够得到很高的铺展，在皮肤上使用后快速吸收，最后给人以丝滑的皮肤感觉。这种产品包装瓶通常含有一个小球，以便在使用前对配方进行研磨，以确保其宏观的均匀性。几年前，这种产品也进入了欧洲市场，在那里它们与袖珍防晒产品有关，但现在只占最近推出的产品的2.5%。在亚太地区，浅凝胶乳液已成为流行的水性乳液，并从水-硅树脂体系中赢得了市场份额。
英文原文
In NA, sprays including emulsion sprays and even more lipo-alcoholic clear continuous sprays are very popular, and have an important market share in NA, with almost 25% of the launched products. This percent- age is much lower in LA, EU, and AP, with 13%, 9%, and 5%, respectively. The packaging for this type of product is mainly based on aerosol cans. This form of application is considered very convenient and easy to use. The pres-ence of ethanol in generally high amounts provides a nongreasy skin feeling with fast skin absorption of the product. This kind of sunscreen is also popular in Europe; there is, however, a tendency to reduce the amount of ethanol, presumably to decrease potential skin irritation. Moreover, in Europe this type of formulation is mainly packaged in normal pump spray bottles, with aerosol cans being less trendy and requiring a special labeling for flammability. Some products in the United States have indeed been withdrawn from the market due to that flammability hazard when propellants are used.
对应中文
在北美，包括乳液喷雾剂和更多脂醇透明连续喷雾剂在内的喷雾剂非常流行，在北美市场占有重要的市场份额，几乎占已发布产品的25%。这一百分比在南美、欧盟和亚太地区要低得多，分别为13%、9%和5%。这类产品的包装主要以气雾罐为基础。大家普遍认为这种形式是非常方便和易于使用的。通常大量的乙醇能提供一种柔软的皮肤感觉，并能快速被皮肤吸收。这种防晒霜在欧洲也很流行；然而，趋势是减少乙醇的用量，为了减少潜在的皮肤刺激。此外，在欧洲这种配方主要包装在普通泵式喷雾瓶中，气雾罐不太流行，需要特殊的易燃性标签。美国的一些产品确实已经退出市场，因为在使用推进剂时存在易燃危险。
Day care with UV protection
防紫外线日常皮肤护理
英文原文
The products that we considered as skin care with UV protection were those launched products that explicitly promoted daily use. Beyond the products assigned as mere sunscreens, we observe a growing trend in the introduction of skin care products with UV protection. Face care and foundation products, especially BB creams (short for blemish balm), contribute to about 20% of the products with sun protection introduced last year in NA and EU, and about 10% in LA and AP. BB creams have achieved great success, first at their place of origin in Germany, then in Korea, and now around the globe. They aim to cover skin imperfections, keeping a natural skin look, and embrace combinations of claims such as moisturizing,anti-aging, skin lightening, and UV protection. BB creams are characterized by their multifunctionality. From BB creams, now CC creams (short for color correction) have been emerging; these products exhibit the benefits of BB creams and are like a skin care product with natural, light coverage benefits. UV such.
对应中文
我们认为具有紫外线防护的皮肤护理产品是那些明确提倡日常使用的产品。除了指定为仅仅为防晒霜的产品外，我们还观察到，具有紫外线防护功能的护肤品的引入呈增长趋势。面部护理和粉底产品，特别是BB面霜（污点膏的简称），占去年在北美和欧盟推出的防晒产品的20%左右，在洛杉矶和亚太地区约占10%。BB霜取得了巨大的成功，首先是在德国，然后是在韩国，现在遍布全球。他们的目标是覆盖皮肤缺陷，保持自然的皮肤外观，并达到其所声明具有的综合效果组合，包含保湿、抗老化、美白和防紫外线等。BB乳膏的特点是其多功能性。从BB面霜，现在CC面霜（颜色校正的缩写）已经出现；这些产品展示了BB面霜的优点，就像一种皮肤护理产品，具有自然、轻覆盖的优点。
英文原文
Daily care with a UV filtering system should not exhibit high SPF values but rather balanced protection over the complete UV range; UVA radiation is likely to play an important role for chronic photodamages such as visible signs of premature skin aging photoimmuno- suppression and contribution to skin cancer by gen- eration of radical oxygen species. A daily use of skin care with sun protection has been shown to prevent acute UV-induced histologic damage in human skin compared with the intermittent use of sunscreen with equal or even higher SPF.
对应中文
紫外线过滤系统的日常护理不应表现出高SPF值，而应在整个紫外线范围内提供平衡保护；UVA辐射可能在慢性光损伤中发挥重要作用，例如导致皮肤过早老化的明显迹象、光免疫抑制、以及自由基氧物种的生成导致皮肤癌。与间歇使用SPF相等甚至更高的防晒霜相比，每日使用防晒护肤品可以防止急性紫外线引起的人体皮肤组织损伤。
Protecti****onBasics of a sunscreen composition
防晒成分的基本知识
英文原文
The three core components categories required in sunscreens are UV filters, emollients, and emulsifiers; secondary components are photostabilizers, film formers, boosters, and sensory enhancers.
对应中文
防晒霜所需的三种核心成分是紫外线过滤器、润肤剂和乳化剂；次要成分是光稳定剂、成膜剂、助推剂和感官增强剂。
UV filters
紫外线滤光片
英文原文
The core active ingredients required to achieve UV protec- tion are inevitably UV filters. A judicious combination of the UV filters enables the achievement of a high UV protection performance while maintaining pleasant formula- tion aesthetics. Targeted light skin feeling can be achieved by choosing the right filter system, as certain UV filters may impart an unwanted greasy and heavy skin feel. In addition, the tendency toward the development of sun- screens with high SPFs leads to an increased concentration of UV filters, mainly loaded in the oil phase, in association with the required emollients. It becomes a challenge to stabilize the formulations that have such a high oil phase content while simultaneously maintaining the pleasant aesthetics of the product. To overcome this issue, some filters are available for the water phase such as the soluble UVB filter PBSA, the dispersible UVB filter TBPT, and the broad-spectrum filter, as well as the alternative to the nor- mally oil-soluble broad-spectrum filter BEMT, embedded in a water-dispersible PMMA matrix. The incorporation of these UV filters prevents overloading of the oil phase and consequently offers more flexibility to the formulator regarding sensorial adjustment. Additionally, the presence of UV filters in the two phases of an emulsion leads to an improved efficacy related to the more homogeneous film left on the skin after application and water evaporation.
对应中文
实现紫外线防护所需的核心活性成分是紫外线过滤器。紫外线滤光片的合理组合可实现高紫外线防护性能，同时保持舒适的外观。选择合适的过滤系统可以达到目标的轻薄肤感，因为某些紫外线过滤器可能会带来不必要的油腻和厚重的肤感。此外，高SPF防晒霜的发展趋势导致紫外线滤光片的浓度增加，主要装载在油相中，与所需的润肤剂相关。如何稳定具有如此高油相含量的配方且同时保持产品的舒适感和美感成为一个挑战。为了克服这一问题，一些过滤器可用于水相，如可溶性UVB过滤PBSA、可分散UVB过滤TBPT和广谱过滤器，以及嵌入水分散聚甲基丙烯酸甲酯基体中的非油溶性广谱过滤BEMT的替代品。这些紫外线过滤器的结合防止了油相过载，从而为配方制定者提供了更多关于传感器调整的灵活性。此外，在乳液的两个阶段中存在UV滤光片，这会导致与涂抹和水分蒸发后留在皮肤上的更均匀薄膜相关的功效得到改善。
Emollients
润肤剂
英文原文
Besides UV filters, emollients are key components in sun- screens. They play a triple role, which includes solubilizing,photostabilizing, and sensorial enhancing properties. Firstly, emollients enable solubilization of crystalline UV filters, a prerequisite for their functionality as UV absorb- ers, and homogeneous distribution of the UV filters in the formulation itself. Examples of effective solubilizers of UV filters are the well-used benzoate esters or phenethyl benzoate.
对应中文
除了紫外线滤光片，润肤剂也是防晒霜的关键成分。它们起着三重作用，包括溶解，光稳定和感官增强特性。首先，润肤剂能够溶解结晶紫外线滤光片，这是其作为紫外线吸收剂功能的先决条件，并且在配方中均匀分布紫外线滤光片。紫外线滤光片的常见有效增溶剂包含长期以来使用良好的苯甲酸酯或苯乙基苯甲酸酯。
英文原文
Some emollients have also be shown to help in the photostabilization of photounstable UV filters, especially avobenzone (BMBM), which goes through a molecular breakdown process when subjected to UV irradiation, leading to nonabsorbing by-products. Some emol- lients show quenching efficacy with regard to the excited state of BMBM to avoid photodegradation of the molecule. Examples of such compounds include ethylhexyl methoxycrylene, diethyhexyl 2,6- naphthalate, butyloctyl salicylate, tridecyl salicylate, polyester-8, diethylhexyl syringylidene malonate, benzotriazolyl dodecyl p-cresol, etc.
对应中文
一些润肤剂也被证明有助于光不稳定紫外线滤光片的光稳定化，特别是苯并噻吩（BMBM），它在受到紫外线照射时会经历一个分子分解过程，形成不吸收的副产物。一些分子活性剂对BMBM的激发态表现出猝灭效应，以避免分子的光降解。这种化合物的例子包括甲氧基二乙基己酯、2，6-萘二甲酸二乙基己酯、水杨酸丁酯、水杨酸十三酯、聚酯-8、丁基己基丁二酸二酯、苯并三唑基十二烷基对甲酚等。
英文原文
Finally, emollients also strongly impact the skin feeling in terms of ease of spreading, greasiness,stickiness, etc. To that end, emollients such as dibutyl adipate, dicaprylyl carbon- ate, coco caprylate, propylheptyl caprylate, are particularly suitable for sun care formulations, because they show a good solubilizing power of crystalline UV filters and at the same time provide a light nongreasy skin feel.
对应中文
最后，润肤剂还强烈影响皮肤的感觉，如易于涂抹、油腻、粘性等。为此，如己二酸二丁酯、二丙烯基碳酸酯、椰子辛酸酯、丙基庚基辛酸酯等润肤剂特别适用于防晒配方，因为它们显示出结晶紫外线滤光片的良好溶解能力，同时提供一种轻而不油腻的皮肤感觉。
Emulsifier systeProtectio****n Sunglasses
乳化剂系统
英文原文
The emulsifier system defines the emulsion type, oil-in- water (O/W), or water-in-oil (W/O) system. Generally, O/W systems are preferred for their easier spreading and lighter skin feel. The external water phase that mostly evaporates during application may also provide a fresh and pleasing sensation. Anionic emulsifiers, such as potassium cetyl phosphate, sodium cetearyl sulfate, C20–22 alkyl phosphate, are often used in sunscreens at low concentra- tions, and allow the incorporation and stabilization of inorganic UV filters. Furthermore, a combination of anionic and nonionic emulsifiers, including PEG-100 stea- rate, ceteareth types, and glyceryl stearate, allows the sta- bilization of high oil phase contents that are frequently required for the achievement of high SPF values. Some glucoside-, lecithin-, phosphate-based emulsifiers com- bined with fatty alcohol enable the building of lamellar liquid-crystalline structures that positively impact formu- lation stability, skin hydration, and skin compatibility. The water resistance of O/W systems is generally lower as hydrophilic emulsifiers re-emulsify and promote a wash- off of sunscreen film on skin with water contact. Con- versely, W/O systems are recognized for their contribution to improved water resistance properties as they typically do not contain any hydrophilic emulsifiers and are thus often used for sunscreens intended for children. Sunscreens for children often contain lipophilic-coated inorganic UV filters that are also easier to be dispersed and stabilized in higher amounts when formulated in W/O systems. W/O emulsifiers often used in sun care are, among others, PEG-30 dipolyhydroxystearate, polyglycreyl-2 dipolyhy- droxystearate, and polyglyceryl-3 diisostearate.
对应中文
乳化剂体系定义乳液类型、水包油(O/W)或油包水(W/O)体系。一般来说，O/W系统因其更容易涂抹和皮肤感觉更轻而更受欢迎。在使用过程中大部分蒸发的外部水相也可以提供清新和愉悦的感觉。阴离子乳化剂，如十六烷基磷酸钾、十六烷基硫酸钠、C20-22烷基磷酸酯，常用于低浓度的防晒霜中，并允许加入和稳定有机紫外线滤光剂。此外，阴离子和非离子乳化剂的组合，包括PEG-100硬脂酸酯、十六烷基型和硬脂酸甘油酯，可以稳定高油相含量，而这些高油相含量往往是获得高SPF值所必需的。一些以葡萄糖苷、卵磷脂和磷酸盐为基础的乳化剂与脂肪醇联合使用，可形成薄层状液晶结构，对配方稳定性、皮肤水合作用和皮肤相容性产生积极影响。O/W体系的耐水性一般较低，亲水乳化剂会重新乳化，并导致皮肤上与水接触的防晒膜被洗脱掉。相反，W/O体系因其对改善防水性能的贡献而被认可，因为它们通常不含任何亲水性乳化剂，因此经常用于儿童防晒霜。儿童防晒霜通常含有亲油性无机紫外线过滤器，在W/O体系中配制中更容易分散和稳定。防晒中经常使用的W/O乳化剂有PEG-30二聚羟基硬脂酸盐、聚甘油基-2二聚羟基硬脂酸盐和聚甘油基-3二异硬脂酸盐。
Rheology modifiers
流变改性剂
英文原文
The final product properties for viscosity and spreadability are strongly influenced by rheology modifieres. In W/O systems, thickeners that are introduced in the external oil phase include fumed silica, organophilic clays, and most frequently waxes such as fatty alcohols, fatty acids, glycer- ides, and ester waxes. Waxes are not shear thinning com- pared with fumed silica. O/W systems might contain starch-, cellulose-, hydrophilic clay-based viscosity enhancers. However, generally the thickening system con- tains synthetic polymeric compounds based on acrylates that are dispersed and neutralized in the external water phase. Furthermore, hydrophobically modified polymers of acrylic acid, sulfonic acid, or acrylamide, generally preneutralized, show additional benefits such as emulsify- ing properties or water resistance improving properties. Synthetic polymers show a shear-thinning behavior; the thickened water phase generally breaks on skin during cream application that leads to an ease of spreading of the product. Care must be taken in the choice of the synthetic polymer thickener and of the inorganic UV filter grade, if both are present in a formulation, because synthetic poly- mers generally show poor compatibility with inorganic UV filters. Additionally, the introduction of natural gums, such as xanthan gum, mostly has a stabilizing rather than thickening effect.
对应中文
流变改性剂对最终产品的粘度和铺展性影响很大。在W/O体系中，引入外部油相的增稠剂包括气相二氧化硅、亲有机粘土和最常见的蜡，如脂肪醇、脂肪酸、甘油酯和酯蜡。蜡与气相二氧化硅相比不具有剪切稀化作用。O/W体系可能含有淀粉、纤维素、亲水性粘土基增粘剂。然而，增稠体系通常包含以丙烯酸酯为基础的合成聚合物，这些聚合物分散在外部水相中并被中和。此外，疏水改性的丙烯酸、磺酸或丙烯酰胺聚合物（通常为丙烯酰化）表现出额外的优点，如乳化性能或改善耐水性。合成的聚合物表现出剪切变稀的行为；在使用乳霜时，增稠的水相通常会在皮肤上破裂，从而使产品易于涂抹。如果配方中存在合成聚合物增稠剂和无机紫外线滤光片，则在选择合成聚合物增稠剂和无机紫外线滤光片时必须小心，因为合成聚合物通常与无机紫外线滤光片的相容性较差。此外，引入天然胶，如黄原胶，大多具有稳定作用，而不是增稠作用。
Boosting ingredients
增强成分
英文原文
Additional help increasing the performance of a sunscreen is provided either by boosting the efficacy of the UV absorber system or by improving the film-forming property on skin. Hollow particles consisting of styrene/ acrylates copolymer act by increasing the optical pathlength of radiation due to their scattering properties, thereby augmenting the probability of UV light meeting a UV absorber molecule before reaching the skin surface. The same principle is valid for particulate filters such as MBBT and TBPT that on top of their absorbing efficacy also scatter UV light.
对应中文
另外，还可以通过提高紫外线吸收剂系统的功效或通过改善产品在皮肤上的成膜性来提高防晒霜的性能。由苯乙烯/丙烯酸酯共聚物组成的空心颗粒通过其散射特性增加了辐射光路长度，从而增加紫外线在到达皮肤表面之前与UV吸收剂分子相遇的概率。同样的原理也适用于微粒过滤器，如MBBT和TBPT，它们除了吸收效率高以外、还散射紫外线。
Sensory enhancers
感官增强剂
英文原文
Finally, sensory enhancers may be added to create an aesthetically appealing formulation. Sensory enhancers mainly are powders or silicones fluids/silicone powders to improve spreading, reduce tack and greasiness. Depending on their particle size and particle shape, powders might adsorb oil, ease spreadability, provide matte and powdered finish, reduce tackiness, or impart velvety touch. Commonly used powders are nylonbased compounds, corn starch derivatives, polymethylsilsesquioxanes, polymethylmethacrylate silica, HDI/trimethylol hexyllactone crosspolymer (and) silica, boron nitride.
对应中文
最后，可以添加感官增强剂，以创造一种在使用感受和感官效果上更具吸引力的配方。感官增强剂主要是粉末或硅酮液体/硅酮粉末，以改善防晒霜的铺展性能、减少粘性和油腻。根据它们的粒径和形状，粉末可以吸附油，易于铺展，提供哑光和粉末饰面，降低粘性，或提供天鹅绒般的触感。常用粉末为尼龙基化合物、玉米淀粉衍生物、聚甲基硅倍半氧烷、聚甲基丙烯酸甲酯-二氧化硅、HDI/三羟甲基己基内酯交联聚合物（和）二氧化硅、氮化硼。
Sunscreen film on skin
皮肤上的防晒膜
英文原文
The UV filter system, the proper dispersion, and the solubilization of the UV filters in the emulsion and finally the uniform distribution of the UV-absorbing molecules on skin are key factors for achieving optimum performance. The sunscreen film after application should be as uniform as possible, ideally an identical cream thickness over the whole covered body surface. The sunscreen film is composed of a multitude of different thicknesses. During application, creams usually have tendency to fill the valleys, leaving the peaks only slightly covered with a thinner film.
对应中文
防晒膜最佳性能相关的关键因素包括紫外线过滤系统、适当的分散度、紫外线过滤器在乳液中的溶解度以及最终紫外线吸收分子在皮肤上的均匀分布。涂抹后的防晒膜应尽可能均匀，理想情况下，整个被覆盖的身体表面都应具有相同的乳霜厚度。防晒膜由多种不同的厚度组成。在使用过程中，面霜通常会填满皮肤低谷，使峰处仅被一层较薄的膜略微覆盖。
Sensory characteristics,consumer compliance,and real-life efficacy
感官特征、消费者依从性和真实功效
英文原文
There are various reasons why people do not always, or ever, use sunscreen as a protective measure against UV radiation, such as ‘sunscreens produce a nonphysiological feeling on skin’, or ‘it takes too much time’, ‘it is greasy’, ‘it feels hot & sweaty’, ‘it leaves a film’, or just because they ‘forgot to apply’.
对应中文
无论如何，人们不总是使用防晒霜作为紫外线辐射防护措施的原因有很多，例如“防晒霜会在皮肤上产生不自然（非生理）的感觉”，或者“时间太长”、“太油腻”、“感觉热且出汗”、“会留下一层薄膜”，或者仅仅因为他们“忘记使用”。
英文原文
The most efficient sunscreen regarding SPF and UVA protection, photostability of UV filters, and water resistance can only provide the claimed and expected photoprotection if the user applies it in the amount of the performance testing procedure and as uniformly as possible. This is known as consumer compliance. As reported by several authors, consumers generally apply too little, only a quarter to half of the quantity used for the official in vivo SPF testing.
对应中文
防晒霜的各种性能，如SPF和UVA保护、UV滤光片的光稳定性和耐水性等，只能在用户按照性能测试程序的量使用、并且尽可能保持厚薄均匀的前提下，才可能达到预期。这就是所谓的消费者依从性。正如几位作者所报告的，消费者通常使用太少，仅为官方活体SPF检测使用量的四分之一到一半。
英文原文
Compared with the first sunscreens where aesthetics were a secondary aspect, there is at present a high demand from consumers with regard to the sensorial characteristics. Overall, products with low viscosity (sprays, lotions) or formulations that break on the skin during application (gel-creams) were the most launched products last year worldwide. This is a response to the preference of users for products that spread easily during application. The suncare vehicle (emulsion type, emollients) impacts sensorial attributes of the product such as ease of distribution during application, and in the same manner it impacts the willingness of the consumer to use that product. A consumer study with four distinct sunscreens has, indeed, shown a strong correlation between the distribution properties and the willingness to use the sunscreen. The amount applied by volunteers also strongly depends on the formulation and its sensorial behavior as shown by Pissavini and Diffey. This means that sunscreens with identical nominal SPF values will, in the end, exhibit a different UV protection performance depending on their sensorial characteristics. It is thus the ultimate objective for sunscreen manufacturers to develop formulations that improve consumer compliance by proposing products that consumers are able and willing to apply properly, that is, the right amount in a uniform way to achieve the promised protection. This has been emerging by sunscreens with diverse appealing claims such as ‘light skin feeling’, ‘dry touch’, or ‘wet skin’ in order to match users’ expectations. Sensory characteristics, consumer compliance, and efficacy under reallife conditions are inevitably strongly linked. such.
对应中文
与将美学效果放在次要地位的防晒霜相比，目前消费者对防晒霜感官特性的要求很高。总的来说，低粘度产品（喷雾剂、乳液）、或在使用过程中会在皮肤上破裂的配方（凝胶霜）是去年全球推出最多的产品。这是防晒霜产品研发对用户偏好的回应，用户喜欢防晒霜易于铺展的特性、则此类产品相应增加。防晒霜载体（乳液型、润肤剂）影响产品的感官属性，如在使用过程中易于涂抹，并且以同样的方式影响消费者使用该产品的意愿。事实上，一项针对四种不同防晒霜的消费者研究表明，防晒霜的分布特性与使用意愿之间存在着很强的相关性。如Pissavini和Diffey所示，志愿者使用的剂量也强烈依赖于配方及其感官特性。这意味着，具有相同标称SPF值的防晒霜最终将根据其传感特性表现出不同的紫外线防护性能。因此，防晒霜制造商的最终目标是开发配方，通过推荐消费者能够并愿意正确使用的产品，即以统一的方式使用适当的量，以实现其所承诺的保护效果，从而提高消费者的依从性。这一点已经在防晒霜中显现出来，现在防晒霜有多种吸引人的说法，如“轻薄的皮肤感觉”、“干爽的触感”或“湿润的肌肤”，以满足用户的期望。感官特征、消费者依从性和现实生活条件下的功效不可避免地紧密联系在一起。
FACTS AND FICTION
误解与事实
Myth#1: SPF=UVB protection
误解1：SPF=UVB防护
英文原文
A common myth is that erythema is only caused by UVB radiation and thus that the SPF only shows protection against UVB. This is evidently not true as has already been discussed in the introduction, but the myth is still very widespread. Even the FDA helped proliferate this myth a few years ago in their ‘proposed rule’ 2007. The FDA had suggested that SPF should be renamed as UVB-SPF. In response to that proposed rule, Sayre et al. stated that: UVB accounts for 80%–91% of the erythemic effectiveness of the specified UV solar simulator. Analysis indicates that if 100% of the UVB is blocked, it is mathematically impossible to achieve an SPF in excess of 11 without also blocking at least some UVA. Consequently significant UVA protection must be provided for sunscreen products to achieve SPFs of 15 and higher. Figure 12 con- firms the findings of Sayre on the sunscreen simulator. Practically complete blockage of UVB by means of the two most efficient UVB filters (5% EHT plus 10% DBT) yields an SPF 14, whereas with the addition of only 4% bisoctrizole (MBBT) the SPF jumps to SPF 50. The 4% MBBT covers about 80%–90% of the UVA range (corre- sponding to 10%–20% transmission) as can be seen in the transmittance chart.
对应中文
一个常见的误解是红斑仅由UVB辐射引起，因此SPF仅对UVB起保护作用。正如在引言中已经讨论过的那样、这显然是错误的认知，但这个说法仍然很常见。就连FDA也在几年前的“拟议规则”中助长了这一谣言。FDA曾建议将SPF改名为UVB-SPF。针对该建议规则，Sayre等人指出：UVB占指定紫外线太阳模拟器热疗效果的80%-91%。分析表明，如果100%的UVB被阻断，则在数学上不可能在不阻断至少一些UVA的情况下实现SPF超过11。因此，必须为防晒产品提供重要的UVA保护，使其SPF达到15或更高。（文中）图12证实了Sayre在防晒霜模拟器上的发现。通过两个最有效的UVB过滤器（5%EHT加10%DBT）几乎完全阻断UVB，产生SPF 14，而仅添加4%双辛唑（MBBT）时，SPF跃升至SPF 50。如（文中）透射率图所示，4%MBBT覆盖约80%-90%的UVA范围（对应于10%-20%的透射率）。
Myth#2: ‘chemical’ UV filters absorb, ‘physical’ filters reflect and scatter
误解2：“化学”紫外线滤光片吸收紫外线，“物理”滤光片反射和散射紫外线
英文原文
A traditional view classifies sunscreens as ‘chemical’ or ‘physical’, referring to the solubility or insolubility of the particles. Such labels promote a misperception regarding how and why sunscreen protects the skin. The effectiveness of UV filters is based on their ability to absorb the selected wavelengths, whether in the visible (400–700 nm), UVA (320–400 nm), or UVB (290–320 nm) range as described earlier in this paper.
对应中文
传统观点将防晒霜分为“化学”或“物理”两类，指的是颗粒的溶解度或不溶性，但此类标签会导致人们对防晒霜保护皮肤免受光伤害的方式和机制产生误解。紫外滤光片的有效性取决于它们对特定波长的吸收能力，特定波长包括可见光（400-700 nm）、UVA（320-400 nm）或UVB（290-320 nm）（如本文所描述的那样）。
英文原文
In summary, TiO2 and ZnO are good sunscreens because of their semiconductor-like electronic properties as solids and not because of their scattering properties. To the contrary, scattering and reflection are undesired properties, leading to the ‘whitening’ effect during application on skin and thus to less compliance. The labels ‘chemical’ and ‘physical’ sunscreen could be replaced by ‘soluble’ and ‘insoluble’ sunscreen, or better yet eliminated altogether as descriptors.
对应中文
综上所述，二氧化钛和氧化锌之所以是很好的防晒霜，是因为它们作为固体具有类似半导体的电子特性，而不是因为它们的散射特性。相反，散射和反射是不受欢迎的特性，导致在皮肤上涂抹时产生“美白”效应，从而降低用户的依从性。“化学”和“物理”防晒霜的标签应该被“可溶性”和“不溶性”防晒霜所取代，或者更好的是，作为描述词完全消除。
Myth#3: SPF 30 protects only marginally better than SPF 15 sunscreen
误解3：SPF30的防晒效果仅略好于SPF15防晒霜
英文原文
Another popular misconception is that SPF 30 is not twice as effective as SPF 15 sunscreen, or SPF 60 not twice as effective as SPF 30, etc. To be precise, ‘SPF’ refers to preventing sunburn under laboratory conditions, for example, at 2 mg/cm2 application amount, protection against other endpoints or against erythema under reallife conditions may indeed be different. The argument goes: an SPF 30 sunscreen filters 96.7% of the erythemogenic UV rays, whereas an SPF 60 sunscreen filters out 98.3%; meaning only 1.6% more. For the impact on humans, it is, however, not relevant how much is filtered out, but rather how much is transmitted onto the skin. An SPF 60 sunscreen transmits 1.7% compared with 3.3% by an SPF 30 sunscreen, that is, half as much. The 1.6% difference thus corresponds to a factor of 2, which is what we expect. Illustration and animation of these facts can be found in Osterwalder and Herzog and animated on YouTube.
对应中文
另一个普遍的误解是，SPF30的防晒效果不是SPF15的两倍，或者SPF60的效果不是SPF30的两倍，等等。准确地说，“SPF”指的是在实验室条件下防止晒伤，例如，在2mg/cm2 的涂抹量时，对其他端点或现实生活条件下的红斑的保护可能确实不同。理由是：SPF30防晒霜过滤96.7%的致热紫外线，而SPF60防晒霜过滤98.3%；这意味着只多了1.6%。然而，对于对人体的影响，有多少被过滤掉并不重要，重要的是有多少传播到皮肤上。SPF60防晒霜的透光率为1.7%，而SPF30防晒霜的透光率为3.3%，也就是一半。因此，1.6%的差额相当于我们预期的2倍。这些事实的插图和动画可以在Osterwalder和Herzog中找到，也可以在YouTube上看到动画。
英文原文
Furthermore, there is another argument for choosing the sunscreen with the higher SPF. Pissavini and Diffey show in their paper entitled: ‘The likelihood of sunburn in sunscreen users is disproportionate to the SPF’, that depending on how well a sunscreen is applied, the SPF 30 sunscreen may, in fact, protect disproportionally better than SPF 15. Their simulation reveals that especially if sunscreen is not applied uniformly on the body in the right quantity, the SPF 30 sunscreen protects more than twice as well against sunburn and thus, by implication, against skin cancer.
对应中文
此外，选择SPF较高的防晒霜还有另一个理由。Pissavini和Diffey在题为“防晒霜使用者被晒伤的可能性与SPF不成比例”的论文中指出，SPF30防晒霜的防护效果可能比SPF15要好得多，这取决于防晒霜的使用情况。他们的模拟显示，特别是如果防晒霜没有以正确的量均匀涂抹在身体上，SPF30防晒霜对晒伤的保护效果是前者的两倍多，因此也就是说，它可以预防皮肤癌。
Myth#4: critical wavelength CW=370nm is good enough UVA protection
误解4：临界波长CW=370nm足够好的UVA防护
英文原文
In June 2011, the FDA released a final sunscreen rule that regulates for the first time UVA protection in the United States. The proposed rule from 2007, including in vivo assessment of UVA protection, was completely abandoned and replaced by the critical wavelength (CW), an in vitro determined metric CW ≥ 370 nm, as sole UVA criterion to make the broad-spectrum claim. For sunscreens with SPF ≥15, the claim ‘reduces risk of skin cancer’ can be made in addition. The FDA bases this claim on the study by Green et al.in Australia in the early 1990s. The sunscreen used by the intervention group showed less skin cancers after 4 years and less malignant melanoma in a follow-up of the same cohorts after 15 years. At that time, the first UVA filter, BMBM, had just been introduced. It consisted of 8% octinoxate (EHMC) and 2% BMBM and had an SPF of 16. Today, we know that this sunscreen in the intervention group was not photostable, which means we can expect yet better protection from currently available sunscreens that contain modern UV filters.
对应中文
2011年6月，美国食品和药物管理局（FDA）发布了一项最终的防晒规则，首次规范了美国的UVA防护。2007年提出的规则，包括对紫外线防护的活体评估，已被完全停用，取而代之的是临界波长(CW)——体外确定的指标CW≥370 nm从此作为唯一对应广谱要求的紫外线标准。对于防晒指数为≥15的防晒霜，还可以标注“降低皮肤癌风险”。FDA基于1990年代初Green等人在澳大利亚进行的研究提出这一主张。干预组使用的防晒霜在4年后显示皮肤癌较少，在15年后对同一队列的随访中显示恶性黑色素瘤较少。当时，第一个UVA过滤器BMBM刚刚推出。它由8%辛氨酯（EHMC）和2%BMBM组成，SPF为16。今天，我们知道干预组中的这种防晒霜不耐光，这意味着我们可以期待对含有现代紫外线滤光片的现有防晒霜有更好的保护。
Myth#5: SPF is exponential function of application amount of the sunscreen
误解5：SPF是防晒霜用量的指数函数
英文原文
The final popular misconception to be discussed refers to the relationship between application amount of sunscreen and the resulting SPF. Statements such as the following are often heard, especially among dermatologists: ‘It turns out that if you apply half the amount, you get the protection of only the square root of the SPF’. Faurschou and Wulf seemed to confirm an exponential, convexshaped SPF- vs-application-amount relationship in their in vivo experiment, but they used a UVB lamp for their SPF measurements, apparently also confined by myth #1 (SPF = UVB). Because common sunscreens protect the UVB range very well, it is not surprising that they found an exponential relationship. Let us think of a mental experiment with an extremely UVB-biased sunscreen measured with a proper solar simulator lamp that also emits UVA radiation. The relationship between SPF and application amount is rather a concave- than a convexshaped one; thicker and thicker layers of sunscreen still transmit a lot of UVA radiation and thus do not allow the SPF to rise proportionally, let alone exponentially. The relationship SPF vs. amount for common, slightly UVB-biased sunscreen will be in between these two examples of convex and concave shape and thus be quasi linear. Such a behavior can also be observed by calculating combinations of UV filters on the sunscreen simulator. Figure 14a shows two extreme cases of SPF 15 sunscreens: one completely UVB-biased (UVA/UVB = 0.16) and one with a uniform UVB-UVA profile (UVA/UVB = 1.0). The two SPF 60 sunscreens in Fig. 14b confirm this result. The concave curve due to the UVB-bias (UVA/UVB = 0.33) is less pronounced because high SPF sunscreens are not possible without an UVA protection (compared with myth #1).UV such.
对应中文
最后一个要讨论的流行误解是防晒霜的使用量和由此产生的SPF值之间的关系。人们经常听到这样的说法，尤其是在皮肤科医生中：“结果是，如果你涂抹一半的量，你只能得到SPF值的平方根的保护。”Faurschou和Wulf在他们的活体实验中似乎证实了指数形的SPF-用量的关系，但他们使用UVB灯来测量SPF，显然也受到了误解#1(SPF=UVB)的限制。让我们想想一个心理实验，用一个合适的太阳模拟灯测量一个极端偏向UVB的防晒霜，它也会发出UVA辐射。防晒霜的防晒系数与使用量之间的关系是凹形的，而不是凸形的；越来越厚的防晒霜仍然会透射大量的UVA辐射，因此不允许防晒霜的防晒系数按比例上升，更不用说呈指数上升了。对于常见的、略带UVB偏向的防晒霜，SPF值与用量的关系介于这两个凸形和凹形之间，因此是准线性的。也可以通过计算防晒霜模拟器上的UV滤光片的组合来观察这种行为。（文中）图14a显示了SPF15防晒霜的两种极端情况：一种完全偏向UVB（UVA/UVB=0.16），另一种具有均匀的UVB-UVA轮廓（UVA/UVB=1.0）。（文中）图14b中的两种SPF60防晒霜证实了这一结果。由于UVB偏差（UVA/UVB=0.33）导致的凹曲线不太明显，因为如果没有UVA保护，不可能达成高SPF防晒霜（与误解#1相比）。
英文原文
In conclusion, in vivo and in silico results confirm the linear relationship between SPF value and application amount. The negative impact of putting on less sunscreen is thus not exponentially related to the amount applied, but it is of course still substantial. This is especially the case if the sunscreen is not applied uniformly. For compensation, it is thus advisable to use a higher SPF than theoretically required.
对应中文
综上所述，活体实验和硅基实验结果证实了SPF值与应用量之间的线性关系。因此，少涂防晒霜的负面影响并不与涂抹的量呈指数关系，但当然仍然很大。如果防晒霜涂得不均匀，后果更甚。因此，为了补偿这些可能的不足，建议使用比理论要求更高的SPF。
CONCLUSION AND OUTLOOK
结论与展望
英文原文
There are lots of half-truths and myths surrounding sunscreens. Five of the most common myths are debunked in this paper: the myth that SPF stands only for UVB protection, the myth about chemical and physical UV filters, the myth that SPF 60 protects only marginally better than SPF 30, the myth that CW 370 nm offers enough UVA protection, and the myth that the SPF varies exponentially with the amount of sunscreen applied on the skin.
对应中文
关于防晒霜有很多半真半假的传言。本文揭穿了五个最常见的谬论：SPF只代表UVB保护的谬论，关于化学和物理紫外线过滤器的谬论，SPF60只比SPF30稍微好一点的谬论，CW370nm对UVA的保护充足的谬论，以及防晒系数与涂抹在皮肤上的防晒霜的数量成指数关系的谬论。
Outlook
展望
英文原文
The major task with respect to the enhancement of the protective benefit of sunscreens is to improve compliance. To accomplish this goal, a comprehensive approach is needed. Improvement in sunscreen technology will further enhance the sensory and tactile profiles and thereby allow the users to enjoy applying sunscreen. An interesting notion to incorporate compliance and performance into a single metric termed SPF in vivo veritas comes from Pissavini et al. Behavioral change will be important, especially among the large part of the population that does not use sunscreen as shown by the very low per capita figures of sunscreen use in the various countries. Depending on the regions and seasons, wearing sunscreen should become a daily routine like brushing teeth, when required by UV climatology, that is, when UV INDEX > 2. The public and even the medical community should be better educated to dispel misconceptions regarding the safety and efficacy of sunscreen, because misguided information creates fears and decreases compliance. Global harmonization will eventually give everybody access to modern UV sunscreen technology, performance measurements, and also adequate criteria for good sunprotection.
对应中文
提高防晒霜的防护效果的主要任务是提高依从性，要实现这一目标，需要一个综合的方法。防晒技术的改进将进一步增强感官和触觉，从而让用户享受涂抹防晒霜的乐趣。Pissaviniet等人提出了一个有趣的概念，将依从性和性能合并到一个称为SPF in vivo veritas的单一度量标准中。行为改变将是重要的，特别是在不使用防晒霜的大部分人口中，各国的人均防晒霜使用率都很低。根据地区和季节的不同，涂抹防晒霜应该成为日常生活，就像刷牙一样，当紫外线气候学要求时，也就是当紫外线指数>2时，公众甚至医学界应该得到更好的教育，以消除对防晒霜安全性和有效性的误解，因为误导信息会产生恐惧并降低依从性。全球协调最终将使每个人都能了解现代紫外线防晒技术、性能测量，以及良好防晒的充分标准。
REFERENCES
1.Osterwalder U, Sohn M, Herzog B. Global state of sunscreens. Photodermatol Photoimmunol Photomed. 2014;30(2-3):62-80.