Maier H, Schauberger G, Brunnhofer K, Hönigsmann H
Division of Special and Environmental Dermatology, University of Vienna Medical School, Währinger Gürtel 18-20, A-1090 Vienna, Austria.
Br J Dermatol. 2003 Apr;148(4):763-9. doi: 10.1046/j.1365-2133.2003.05032.x.
The thickness of the sunscreen layer that is actually applied by consumers under usual conditions has been determined for photoprotective lotions and creams; however, this question is still unanswered for photoprotective lipsticks.
To assess lipstick thickness (area density) and frequency of application per day for two commercially available photoprotective lipsticks with different consistency.
The study consisted of a laboratory test and a field experiment. In the laboratory test the applied lipstick thickness was determined as area density in mg cm(-2) for a group of 28 panellists under standardized conditions. In a separate group of 18 subjects we assessed the area density and the frequency of application per day for two photoprotective lipsticks during a 6-day skiing course.
In the laboratory test the median and 95% confidence interval of the area density was 0.98 mg cm(-2) (0.66-1.65) and 0.86 mg cm(-2) (0.63-1.40) for products A and B, respectively. The respective values of the field experiment were 1.58 mg cm(-2) (0.79-2.23) (product A) and 1.76 mg cm(-2) (1.16-3.50) (product B). Only 11% of all applications of lipstick A and 6% of all applications of lipstick B reached the reference area density of 2.0 mg cm(-2). The difference between the median of the area density for lipstick A (firm consistency) and lipstick B (soft consistency) was not statistically significant. No statistically significant influence on the area density was found for age, sex, photobiological skin type or regular lipstick use. The median daily frequency of application was 2.2 times for lipstick A and 3.0 times for lipstick B.
Our investigation shows that photoprotective lipsticks are applied in a much thinner layer than recommended by international standards (2 mg cm(-2)). This results in a significant reduction of the photoprotective capacity. Furthermore, the frequency of application is too low for adequate protection. Therefore, we propose that the sun protection factor (SPF) should be assessed for an area density that reflects the actual usage patterns. As long as the test protocol is not adapted to the reduced area density, photoprotective lipsticks with high and ultrahigh SPF should be recommended, especially for individuals with increased risk for the development of lip malignancies.
对于防晒乳液和面霜，已确定消费者在通常情况下实际涂抹的防晒层厚度；然而，对于防晒口红，这个问题仍然没有答案。
评估两种具有不同质地的市售防晒口红的厚度（面积密度）和每日涂抹频率。
该研究包括一项实验室测试和一项现场实验。在实验室测试中，在标准化条件下，对一组28名受试者测定涂抹口红的厚度，以毫克每平方厘米（mg cm⁻²）为单位表示面积密度。在另一组18名受试者中，我们在为期6天的滑雪课程中评估了两种防晒口红的面积密度和每日涂抹频率。
在实验室测试中，产品A和产品B的面积密度中位数及95%置信区间分别为0.98 mg cm⁻²（0.66 - 1.65）和0.86 mg cm⁻²（0.63 - 1.40）。现场实验的相应值分别为1.58 mg cm⁻²（0.79 - 2.23）（产品A）和1.76 mg cm⁻²（1.16 - 3.50）（产品B）。口红A所有涂抹情况中只有11%，口红B所有涂抹情况中只有6%达到了2.0 mg cm⁻²的参考面积密度。口红A（质地硬）和口红B（质地软）的面积密度中位数差异无统计学意义。年龄、性别、光生物学皮肤类型或是否经常使用口红对面积密度均无统计学显著影响。口红A的每日涂抹频率中位数为2.2次，口红B为3.0次。
我们的调查表明，防晒口红涂抹的层数比国际标准推荐的（2 mg cm⁻²）薄得多。这导致光保护能力显著降低。此外，涂抹频率过低，无法提供充分保护。因此，我们建议应针对反映实际使用模式的面积密度来评估防晒系数（SPF）。只要测试方案不适应降低后的面积密度，就应推荐具有高和超高SPF的防晒口红，尤其是对于唇部发生恶性肿瘤风险增加的个体。
