378. RECONSTRUCTED HUMAN EPIDERMIS FOR SKIN ABSORPTION TESTING: RESULTS OF THE GERMAN PREVALIDATION STUDY.

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Schafer-Korting¹, M., Bock², U., Gamer³, A., Haberland¹, A., Haltner-Ukaomadu², E., Kaca², M., Kamp³, H., Kietzmann⁴, M., Korting⁵, H.C., Krachter⁶, H-U., Lehr⁷, C.M., Liebsch⁸, M., Mehling⁶, A., Netzlaff⁷, F., Niedorf⁴, F., Rubbelke⁵, M.K., Schafer⁷, U., Schmidt⁸, E., Schreiber¹, S., Schroder⁹, K-R., Spielmann⁸, H., Vuia¹, A. ¹Freie Universität Berlin, Institut für Pharmazie, Berlin, Germany, ²Across Barriers GmbH, Saarbrücken, Germany, ³BASF Aktiengesellschaft, Experimental Toxicology and Ecology, Ludwigshafen, Germany, ⁴Stiftung Tierärztliche Hochschule Hannover, Institut für Pharmakologie, Hannover, Germany, ⁵Ludwig-Maximilians-Universität München, Klinik und Poliklinik für Dermatologie und Allergologie, München, Germany, ⁶Cognis Deutschland GmbH & Co. KG, Düsseldorf, Germany, ⁷Universität des Saarlandes, Biopharmazie u. Pharmazeutische Technologie, Saarbrücken, Germany, ⁸ZEBET, Berlin, Germany, ⁹Henkel KGaA, Düsseldorf, Germany. ATLA, 34, 283-294 (2006).

Summary:
This study by scientists at the Freie Universität Berlin, Across Barriers GmbH, BASF Aktiengesellschaft Experimental Toxicology and Ecology, the Institut für Pharmakologie, Ludwig-Maximilians-Universität München, Cognis Deutschland GmbH & Co. KG, Universität des Saarlandes, ZEBET (Berlin, Germany), and Henkel KGaA demonstrated that MatTek’s EpiDerm in vitro human skin tissue equivalent can be used to predict the percutaneous absorption of materials for regulatory purposes in accordance with the testing principles detailed in OECD 428.

Exposure to chemicals absorbed by the skin can threaten human health. In order to standardise the predictive testing of percutaneous absorption for regulatory purposes, the OECD adopted guideline 428, which describes methods for assessing absorption by using human and animal skin.

In this study conducted by scientists at the Freie Universität Berlin, Across Barriers GmbH, BASF Aktiengesellschaft Experimental Toxicology and Ecology, the Institut für Pharmakologie, Ludwig-Maximilians-Universität München, Cognis Deutschland GmbH & Co. KG, Universität des Saarlandes, ZEBET (Berlin, Germany), and Henkel KGaA, a protocol based on the OECD principles was developed and prevalidated by using reconstructed human epidermis (RHE) including MatTek’s EpiDerm human skin tissue equivalent. The permeation of the OECD standard compounds, caffeine and testosterone, through commercially available reconstructed human epidermis (RHE) models was compared to that of human epidermis and animal skin.

In comparison to human epidermis, the permeation of the chemicals was overestimated when using reconstructed human epidermis (RHE). The following ranking of the permeation coefficients for testosterone was obtained: SkinEthic > EpiDerm, EPISKIN > human epidermis, bovine udder skin, pig skin. The ranking for caffeine was: SkinEthic, EPISKIN > bovine udder skin, EpiDerm, pig skin, human epidermis.

The inter-laboratory and intra-laboratory reproducibility was good. Long and variable lag times, which are a matter of concern when using human and pig skin, did not occur with reconstructed human epidermis (RHE).

Due to the successful transfer of the protocol, it is now in the validation process.

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EpiDerm Data Sheet

EpiDerm Specifications

EpiDerm Technical References

Percutaneous Absorption (EpiDerm Application)

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Applications: Drug absorption - skin, Drug delivery - transdermal, Percutaneous absorption/penetration, Reproducibility - skin tissue models, Transdermal permeation/penetration, Validation - in vitro tissue models

Keywords: Cutaneous Uptake, EpiDerm, EpiSkin, Franz diffusion cells (FDC), Lipophilicity, OECD, Percutaneous absorption, Permeation, SkinEthic

Endpoints: Flux, HPLC, Lag Time, Permeation coefficient (Papp)

Materials Tested: Caffeine, Testosterone

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