日本香粧品学会誌

Vol. 47, No. 3, pp. 176–182（2023）〈Regular Article〉

Evaluation of Skin Permeation Order of Cosmetic Active Compounds
from Commercially Available Cosmetic Products with Diﬀerent Dosage Forms
Using a Three-Dimensional Cultured Human Skin ModelShohei SEKIGUCHI1, Ibuki NARITA1, Shoko ITAKURA1,Hajime KOJIMA2, Kenji SUGIBAYASHI1, 3, Hiroaki TODO1, *(Accepted: June 2, 2023)

Abstract
In vitro skin permeation experiments are useful to evaluate which formulations have a higher skin permeation and/or
concentration. However, the high variability in the permeation rate of chemicals is often concern in the experiments using excised human skin. Then, three-dimensional (3D) cultured human skin models have gained interest as alternative membranes
to evaluate skin permeation of chemicals, although they have a weak barrier function in the stratum corneum. In the present
study, 3D cultured human skin models, such as LSE-high and EpiDerm 606X, were selected, and the permeation rates ofcosmetic active compounds through the skin models were evaluated from commercially available cosmetic products with different dosage forms (lotion, milk, and cream). Following formulations containing diﬀerent lipophilicities of cosmetic activeingredients (tranexamic acid, nicotinic acid amide, and 4-butylresorcinol) were used. We found that the order of skin permeation rate from diﬀerent dosages through 3D skin models corresponded with that obtained through excised human skin,independent of the lipophilicity of the cosmetic active ingredients. In addition, a moderate relationship, but not a 1 : 1 slope,was conﬁrmed between the logarithm of permeability coeﬃcients of chemicals obtained from human skin and those obtained
from 3D skin models. The results indicated that 3D skin models have potential for use in evaluating which formulations orproducts exhibit high permeability.
Key words: in vitro skin permeation experiment, three-dimensional cultured human skin model, cosmetic active ingredients, complex formulation.

1.

Introduction

On April 13, 2009, the Pharmaceutical Aﬀairs Agency ofJapan issued Guidelines for Clinical Evaluation of QuasiDrugs , Issue No. 0413-11). This guideline indicates importantconsiderations when preparing documents related to clinicalevaluation for quasi-drug approval. This material includes
both safety data and data on eﬃcacy or eﬀectiveness andmust be submitted as a part of an application for manufactureand sales approval. In the guideline, a human long-term dosing (safety) study is required at the actual application site of
the quasi-drug. The Japanese Society of Cosmetic Chemists
reported on the concept of dose setting based on in vitro skinpermeation experiments that take into account the concentration in the skin expected from actual use in long-term humandosage (safety) studies2). In vitro skin permeation experimentswith an inﬁnite dose are used to assess the formulation withthe highest skin concentration. Generally, excised human skin

1

Faculty of Pharmacy and Pharmaceutical Sciences, Josai University(1–1 Keyakidai, Sakado, Saitama 350–0295, Japan)
2
National Institute of Health Sciences
3
Faculty of Pharmaceutical Sciences, Josai International University* Corresponding author: Faculty of Pharmacy and Pharmaceutical Sciences, Josai University, 1–1 Keyakidai, Sakado, Saitama 350–0295,
Japan (E-mail: ht-todo@josai.ac.jp)

is considered as the gold standard for in vitro skin permeation
study3). Recently, three-dimensional (3D) cultured humanskin models (3D skin models) have been widely used as analternative membrane to animal and human skins to evaluate
skin irritation/corrosion by topically exposed chemicals. In
addition, many reports have been published on the usefulnessof 3D skin models in in vitro skin permeation test4), although
their barrier function is insuﬃcient compared with that of human skin5, 6). The 3Rs (reduction, reﬁnement and replacementof animal testing) principle is considered in conducting risk
assessments of cosmetic products, instead of in vitro testingwith animal skins7–9). However, chemical permeation through3D skin models greater than that through excised humanskin. Therefore, it is not appropriate to evaluate the cumulative amount of permeation of chemical compounds througha 3D skin model to determine the amount absorbed throughhuman skin. Moreover, the chemical concentration in skin isrelated to the relative ratio of the barrier function of the stra-