Comparison of stratum corneum thickness between two proposed methods of calculation using Raman spectroscopic depth profiling of skin water content.

Background/purpose: The stratum corneum (SC) is the most important layer for the barrier function of skin, so investigation of the SC is very important in cosmetic and medical research. Here, we calculated the SC thickness using the depth profile of the skin's water concentration based on previously described methods, and then compared the results. Methods: Seven Korean women in their 30s participated in this study. Raman spectroscopy was used to measure the in vivo depth profile of skin water concentration. A total of 21 areas were measured at forearm. Microsoft Excel 2007 was used to calculate SC thickness based on the slope and intersection methods. Results: The slope method and the intersection method gave a forearm SC thickness calculated at 21.3 +/- 2.6 mu m and 17.6 +/- 2.8 mu m, respectively. There was a significant difference between the two calculation methods but the two methods showed strong correlation of SC thickness results (r = .899). Conclusion: Although there was a difference in calculated SC thickness of about 20% between the two methods, these results reveal that the two SC thickness calculation methods using Raman spectroscopy were suitable for measuring SC thickness, a finding consistent with other published results.