Epidermal cell culture model derived from rat keratinocytes with permeability characteristics comparable to human cadaver skin

The permeability characteristics of an organotypic epidermal culture model derived from rat epidermal keratinocytes, ROC, and isolated human cadaver epidermis, HEM, were compared. Rat epidermal keratinocyte (REK) cell line was grown for 3 weeks on collagen gel in the absence of feeder cells in culture inserts at an air-liquid interface. Transdermal permeabilities of 18 compounds ranging from 92 to 504 in molecular weight and from -4.3 to 3.9 in log of octanol-water partition coefficient, charged or uncharged, were measured in the culture model and isolated human epidermis. The REK organotypic culture model (ROC) provided a close estimate of human epidermal permeabilities over the whole range of the solutes used with on the average of 2-fold higher permeability coefficients (range 0.3-5.2) than those obtained from isolated human cadaver epidermis. The easily maintained and reproducible ROC model may be useful in screening transepidermal drug permeabilities together with possessing potential for research on dermal formulations, irritation, toxicity and gene therapy.