Method for measuring skin absorbability of a substance

Abstract

A method for measuring skin absorbability of a substance, which includes measuring the amount of the substance which is penetrated into hair follicles; and using the resultant data as an index representing the amount of the substance which is absorbed through skin pores, to thereby determine the amount of the substance absorbed through skin pores and a method for measuring skin absorbability of a substance, which includes bringing the substance into contact with a first surface of a thin film that mimics the skin surface layer, a second surface of the film being brought into contact with artificial sebum; and evaluating the sebum transferability of the substance by using the degree of transfer of the substance to the artificial sebum as an index, are disclosed. A kit for performing the measurement method of the present invention is also disclosed.

What is claimed is:  
     
         1 . A method for measuring skin absorbability of a substance, which comprises measuring the amount of the substance which is penetrated into hair follicles; and using the resultant data as an index representing the amount of the substance which is absorbed through skin pores, to thereby determine the amount of the substance absorbed through skin pores.  
     
     
         2 . A method for measuring skin absorbability of a substance according to  claim 1 , wherein the amount of the substance which is penetrated into hair follicles is determined by applying the substance to a skin model specimen assuming a pseudo-biological state, removing hair follicles from the dermis of the skin model, and measuring the amount of substance which is delivered to the hair follicles.  
     
     
         3 . A method for measuring skin absorbability of a substance according to  claim 2 , which comprises measuring the amount of the substance which is penetrated into hair follicles and the amount of the substance which is penetrated into other skin tissue in the skin model, and by use of these resultant data as an index representing the amount of the substance which is absorbed through skin pores and percutaneously, determining the amount of the substance absorbed through the skin.  
     
     
         4 . A method for measuring skin absorbability of a substance according to  claim 1 , wherein the amount of the substance which is penetrated into hair follicles is determined by removing the hair follicles from the human scalp to which the substance has been applied, and measuring the amount of the substance which is delivered to the hair follicles.  
     
     
         5 . A method for measuring skin absorbability of a substance, which comprises bringing the substance into contact with a first surface of a thin film which mimics the skin surface layer, a second surface of the film being brought into contact with artificial sebum; and evaluating the sebum transferability of the substance by using the degree of transfer of the substance to the artificial sebum as an index.  
     
     
         6 . A method for measuring skin absorbability of a substance according to  claim 5 , wherein the first surface of the film comprises an open system.  
     
     
         7 . A method for measuring skin absorbability of a substance according to  claim 5 , wherein the artificial sebum assumes a fluid state.  
     
     
         8 . A method for measuring skin absorbability of a substance according to  claim 5 , wherein the thin film is a single-layer silicone film, a surface of the film having undergone keratinization, and the substance is brought into contact with the surface which has undergone keratinization.  
     
     
         9 . A kit for carrying out a method for measuring skin absorbability of a substance as recited in  claim 5  comprising: 
 a sealable receptacle in which artificial sebum is placed, the receptacle comprising an opening which includes a fixing means enabling fixation of a thin film so as to cover the opening in a state in which the thin film is removable;  
 a thin film which mimics the skin surface layer, which film is to be applied and fixed onto the opening of the sealable receptacle so as to cover the opening; and  
 artificial sebum which is to be placed in the sealable receptacle.  
 
     
     
         10 . A composition for the scalp and hair comprising, as an ingredient for accelerating skin-pore absorption, an oily ingredient having an I.O.B. value of 0.06-4.0.  
     
     
         11 . A composition for the scalp and hair according to  claim 10 , wherein the oily ingredient having an I.O.B. value of 0.06-4.0 has an organic value of 100-750 and an inorganic value of 50-400.  
     
     
         12 . A composition for the scalp and hair according to  claim 10 , wherein the oily ingredient having an I.O.B. value of 0.06-4.0 has an organic value of 100-750 and an inorganic value of 100-400.  
     
     
         13 . A composition for the scalp and hair according to  claim 10 , wherein the oily ingredient having an I.O.B. value of 0.06-4.0 is an amphipathic substance.  
     
     
         14 . A composition for the scalp and hair according to  claim 10 , wherein the oily ingredient having an I.O.B. value of 0.06-4.0 is liquid at ambient temperature and is a C6-C24 amphipathic substance.  
     
     
         15 . A composition for the scalp and hair according to  claim 10 , wherein the oily ingredient having an I.O.B. value of 0.06-4.0 is a hydrocarbon derivative which has a backbone structure of a C6-C18 hydrocarbon.  
     
     
         16 . A composition for the scalp and hair according to  claim 15 , wherein the hydrocarbon derivative is a fatty acid, an alcohol, an amide, or an ester.  
     
     
         17 . A composition for the scalp and hair according to  claim 10 , wherein the oily ingredient having an I.O.B. value of 0.06-4.0 is one or more oily ingredients selected from the group consisting of lauryl alcohol, lauric acid, lauric acid ethanolamide, lauric acid diethanolamide, monoglyceryl laurate, diglyceryl laurate, oleyl alcohol, oleic acid, oleic acid ethanolamide, oleic acid diethanolamide, monoglyceryl oleate, diglyceryl oleate, isostearyl alcohol, isostearic acid, isostearic acid ethanolamide, isostearic acid diethanolamide, monoglyceryl isostearate, diglyceryl isostearate, stearyl alcohol, stearic acid, stearic acid ethanolamide, stearic acid diethanolamide, monoglyceryl stearate, and diglyceryl stearate.  
     
     
         18 . A composition for the scalp and hair comprising isostearyl alcohol and/or camphor as a skin-pore absorption accelerating ingredient.  
     
     
         19 . A composition for the scalp and hair comprising isostearyl alcohol as a sebum transfer accelerating ingredient.  
     
     
         20 . A composition for the scalp and hair according to  claim 10 , wherein the composition has a product form of hair-growing agent.  
     
     
         21 . A composition for the scalp and hair according to  claim 10 , wherein the composition has a product form selected from the group consisting of a gray-hair prevention agent, shampoo, rinse, rinse-in-shampoo, and treatment.  
     
     
         22 . A hair-growing composition comprising isostearyl alcohol.  
     
     
         23 . A detergent composition for the scalp and hair comprising isostearyl alcohol.  
     
     
         24 . A detergent composition for the scalp and hair according to  claim 23 , wherein the composition has a product form of shampoo or rinse-in-shampoo.  
     
     
         25 . A gray-hair prevention agent comprising isostearyl alcohol.  
     
     
         26 . A hair-removing agent comprising isostearyl alcohl.  
     
     
         27 . A method for measuring skin absorbability of a substance according to  claim 1 , wherein the absorption through skin pores is absorption through hair follicles.