Confocal Raman Spectroscopy for Dermatological Studies

Abstract

Use of Confocal Raman Spectroscopy (CRS) for dermatological studies, including a method for determining the thickness of the Stratum Corneum (SC) on a test area of the skin, and to a method for quantifying the effectiveness of a skin care composition. The methods can be carried in vitro (either artificial skin or a sample of skin) or in vivo (directly on the human skin of a person).

1 . A method for determining the thickness of the Stratum Corneum on a test area of skin comprising the steps of:
 (a) measuring the concentration profile of a Raman-active material as a function of depth within the test area using Confocal Raman Spectroscopy; then   (b) processing, using a computer, the data obtained to determine the thickness of the Stratum Corneum.   
     
     
         2 . The method of  claim 1 , wherein the data is processed using the Weibull algorithm. 
     
     
         3 . The method of  claim 1 , wherein the measurement is made in vivo. 
     
     
         4 . The method according to  claim 1 , wherein the Raman-active material is selected from the group consisting of water, NMF, vitamins, ingredients from a personal care composition, and combinations thereof. 
     
     
         5 . The method according to  claim 4 , wherein the Raman-active material is water. 
     
     
         6 . The method of  claim 1 , wherein the thickness of the Stratum Corneum is determined before and after application of a skin care composition. 
     
     
         7 . The method of  claim 6 , wherein the skin care composition comprises at least one moisturizing agent. 
     
     
         8 . The method of  claim 6 , wherein the Raman-active substance is linked to the effectiveness of the skin care composition. 
     
     
         9 . The method of  claim 8 , wherein the effectiveness of the skin care composition is calculated by selecting a specific relative depth of the Stratum Corneum and comparing the amount of the Raman-active substance present at the specific relative depth before and after the application of the skin care composition.