防曬係數之體內及體外評估的相關性   全文下載

Correlation of In vivo and In vitro Measurements of Sun Protection Factor

本實驗的目的在於探討體內與體外之防曬係數評估的相關性，希望能夠用體外取代體內的評估方式，以節省人力和金錢，更有助於產品設計的方便性。本次實驗採用八個防曬樣品，包括兩種標準品 [FDA （SPF = 4）、COLIPA （SPF = 15）] 和六種市售商品。在體內試驗方面，利用受測者背部的皮膚作為照射範園，塗抹劑量是以每平方公分2毫克來計算，塗抹後等待15分鐘，再以光源於塗抹處進行照射；此光源是採用Multiport UV Solar Simulator，其含有六個光源輪出管，每管之間的劑量以25%遞增，經適量照射後24小時，由皮膚科醫生來判讀最小紅斑劑量（MED）。另一方面，體外試驗的過程中，則以3M Transpore tape來當作人造皮，並利用紫外光穿透率分析儀的Xenon燈來模擬光源，測試結果會由其附屬軟體自動計算出防曬係數值。實驗結果顯示，由體內試驗所計算出的防曬係數值與其標示值較相近，表示在此實驗中防曬係數值於體內試驗之測試結果應可信賴，然而利用統計方法（t-test／ANOVA）來分析體內和體外的相關性，發現在大部分產品中，兩種方法的防曬係數值具有顯著的差異性；因此，防曬係數值在體內和體外試驗的相關性目前仍無法建立；所以利用紫外光穿透率分析儀來評估防曬產品的防曬係數值在體內和體外的相關性之建立，或許不是一個實際可行的分析方法。

In this study, the correlation of measuring sun protection factor (SPF) values between in vivo and in vitro tests was investigated for the purpose of monitoring the in vivo efficacy of sunscreen products using in vitro tests instead of in vivo tests to lessen the labor burden. Eight products, including standard product of the US FDA (SPF 4) and COLIPA (SPF 15) and six commercial products, were included for comparison. For the in vivo test, the test sample was evenly applied to the skin at a concentration of 2 mg/cm2 using a finger stall. The lag time between application and UV irradiation was about 15 min. A Multiport UV Solar Simulator with six outputs was used as the UV source. Six test sites were exposed to UV irradiation with a progression of UV doses of 25% from output to output. The minimal erythemal dose (MED) was assessed visually after 24 hr of UV exposure. During the in vitro test, each sunscreen was evenly spread on 3M Transpore(R) tape and the transmittance was measured with a UV transmittance analyzer equipped with a singleflash xenon lamp. The results demonstrated that the SPF values of the in vivo tests were close to the claimed value, indicating that SPF values measured in this study were reliable. However, statistical analysis by t-test or ANOVA showed that significant difference in SPF values existed between in vivo and in vitro tests for most products. Thus, a correlation of SPF measurement between in vitro and in vivo tests could not be constructed. According to these results, using a UV transmittance analyzer to measure SPF values is not a reliable method to correlate with the results of in vivo tests, and so this is not a practical way to monitor the effectiveness of sunscreen products. 本實驗的目的在於探討體內與體外之防曬係數評估的相關性，希望能夠用體外取代體內的評估方式，以節省人力和金錢，更有助於產品設計的方便性。本次實驗採用八個防曬樣品，包括兩種標準品 [FDA （SPF = 4）、COLIPA （SPF = 15）] 和六種市售商品。在體內試驗方面，利用受測者背部的皮膚作為照射範園，塗抹劑量是以每平方公分2毫克來計算，塗抹後等待15分鐘，再以光源於塗抹處進行照射；此光源是採用Multiport UV Solar Simulator，其含有六個光源輪出管，每管之間的劑量以25%遞增，經適量照射後24小時，由皮膚科醫生來判讀最小紅斑劑量（MED）。另一方面，體外試驗的過程中，則以3M Transpore tape來當作人造皮，並利用紫外光穿透率分析儀的Xenon燈來模擬光源，測試結果會由其附屬軟體自動計算出防曬係數值。實驗結果顯示，由體內試驗所計算出的防曬係數值與其標示值較相近，表示在此實驗中防曬係數值於體內試驗之測試結果應可信賴，然而利用統計方法（t-test／ANOVA）來分析體內和體外的相關性，發現在大部分產品中，兩種方法的防曬係數值具有顯著的差異性；因此，防曬係數值在體內和體外試驗的相關性目前仍無法建立；所以利用紫外光穿透率分析儀來評估防曬產品的防曬係數值在體內和體外的相關性之建立，或許不是一個實際可行的分析方法。