Studies on the in vitro SPF test method of sunscreen products

Transcription

1 Studies on the in vitro SPF test method of sunscreen products KyungHun Son, YoungOk Kim, JungYun Jang, JeongPyo Lee, SeongJun Yang, KyungShin Lee, WonHee Kim, ChongKap Kim*, MoonYoung Heo** and SangSook Choi Drug Evaluation Department, Korea Food & drug Administration, Nokbun-dong, Eunpyung-gu, Seoul, Korea * College of Pharmacy, Chung-ang Universty, 211 Huksuk-dong, Dongjak-gu, Seoul, Korea * College of Pharmacy, Kangwon Universty, Hyoja2-dong, Chunchon, Kangwon-do Korea

2 Abstract The present study was undertaken to develop the in vitro sun protection factor(spf) test method having good correlation with in vivo method using human. The SPFs of 8% homomentyl salicylate, P3 reference standard and commercially available sunscreen products were measured by the in vitro method using SPF 290S analyzer, and the SPFs were compared with the SPFs measured by in vivo test method. In vitro SPFs of 8% HMS and P3 reference standard were 4.9 ± 0.12 and ± There are good correlations; correlation factors were and respectively, between the in vitro and in vivo SPFs for the sunscreen creams and lotions. Correlation factors of makeup base/liquid foundation, lotion labled with shake before use and compact powder were , and respectively. The optimum mixture ratio of compact powder and cream base represents 1:0.8. These results suggest that the in vitro SPF test method will be able to be used as an alternative method for measurement of SPF in case of lotion and cream.

3 Introduction The light sunburn or tanning is occurred by the short-term exposure of ultraviolet radiation but it is possible to occur skin photo aging or skin cancer as a result of cumulative exposure. Because we all know this painful and potentially serious skin injury is caused by solar UV radiation, cosmetics containing sunscreens is usually consumed for precaution regardless of season. The UV protective degree is indicated as the sun protection factor(spf) calculated from the minimal erythema dose(med) on protected human skin and unprotected one. Greiter proposed this concept at first, and SPF has generally used in the world after US adopted it. But this test method using human take some problems. In the case of in vivo test method, it is difficult to get the volunteers, because the erythema is maintained for a few month after testing,, and they can not move for a few minutes or hours. The selection of skin type and evaluation of MED are conducted by the only experts who have the experience and knowledge related to SPF. It costs a great deal because of the clinical expense including the purchase price of equipment and volunteer. The purpose of this study was to develop the in vitro SPF, which dissolves the above problems, and take the good correlation with test method. Therefore in vitro SPFs of the cosmetic products were measured according to the types or components of the products, which in vivo SPFs already were measured and in market.

4 Materials and Instruments SPF standards 8% Homomentyl salicylate(hms) P3 reference standard was prepared in the laboratory Samples Thirty eight functional cosmetics containing the sunscreen ingredients marketed in Korea These samples were measured SPF by in vivo test methods Substrates Transpore Tape TM (3M Co., USA) or Vitro Skin TM (IMS, USA) Instrument SPF 290 Analyzer was purchased form Optometric Co.(Ayer MA, USA), equipped with Xenon Arc Lamp as the light source.

5 Method Optimal substrate 8% HMS was applied on the Transpore tape or Vitro skin, and SPF was measured by in vitro test method. The factors such as the convenience and reproducibility were compared between the two methods. Sample apply The 2 µl/cm 2 of SPF Standards or sample was applied on the front of transpore tape The compact powder was mixed with vaseline(wako, Japan) or Cream base which was directly prepared in the laboratory in the ratio 1:0.6, 1:0.8, 1:1 respectively, and was applied 2 µl/cm 2. Measurement of in vitro SPF Samples was spotted at the several position on the transpore tape and it must be carefully rubbed to uniform a layer The transpore tape was allowed to dry for 1 minutes It was set in sample holder and was measured in vitro SPF with SPF 290 analyzer In vitro SPF was measured at 12 different sites on the Transpore tape. The correlation between the in vivo and the in vitro SPF was calculated.

6 Result Table 1. In vitro SPF of 8% HMS and P3 Reference Standard Sample In vitro SPF Mean RSD (%) 8% HMS P3 RS notification - 8% HMS : 4.47 ± 1.28, P3 Reference Standard : 1.0 ± 3.0

7 in vitro SPF R 2 = vitro S P F in R 2 = Fig. 1 Relationship between and in vitro SPF for cream. Fig. 2 Relationship between and in vitro SPF for lotion.

8 0 4 R 2 = R 2 = in vitro SPF in vitro SPF Fig. 3 Relationship between and in vitro SPF for lotion(shaking). Fig. 4 Relationship between and in vitro SPF for makeup base & liquid foundation.

9 in vitro SPF R 2 = Fig. Relationship between and in vitro SPF for compact powder (compact powder:cream = 1:0.8) in vitro SPF R 2 = R 2 = sample without UV scatter sample with UV scatter Fig. 6 Relationship between and in vitro SPF for sample.

10 in vitro SPF R 2 = R 2 = R 2 = in vitro S P F R 2 = R 2 = R 2 = :1, 1 : 0.8, 1 : 0.6 1:1, 1 : 0.8, 1 : 0.6 Fig. 7 Relationship between and in vitro SPF for compact powder & vaseline mixture. Fig. 8 Relationship between and in vitro SPF for compact powder & cream base mixture.

11 Conclusion The results of this study for correlation between the and in vitro SPF measured using SPF 290 analyzer are follows. 1.In case of liquid samples such as cream and lotion, the results were good when we take hold of 2µl/cm 2 of the samples. In case of compact powders, on conditions that compact powder and cream base are mixed in the ratio of 1:0.8 and we take hold of 2 µl/cm 2 as compact powder, the results were good to experiment. 2.The in vitro SPF of 8% HMS and P3 Reference standard was corresponding with notification article. 3.The correlation coefficient of creams and lotions was good as and respectively. And the correlation coefficient of makeup base/liquid foundation, lotion labeled with shake before use and compact powder was and , 0.984, respectively. Therefore, it is expected that the in vitro SPF test method will be used as an alternative method for and a new test item for quality control sunscreens.