Solvent effects on the harvesting of stratum corneum from hairless mouse skin through adhesive tape stripping in vitro

125 pl of a propylene glycol/ethanol/water vehicle were applied for various lengths of time to 1.77 cm2 area of excised hairless mouse skin sections held in in vitro diffusion cells. After removal from the cell, each skin section was stripped repeatedly with a non-hygroscopic polypropylene tape. The amount of tissue removed in each strip was determined after allowing the volatile solvents to evaporate. Weights were corrected for residual propylene glycol and water, the amounts of which were determined radioisotopitally. More tissue was harvested in the first and second strips from skin conditioned with the vehicle for more than 12 h. The effect of vehicle treatment on stripping properties precludes one from determining drug and vehicle concentration gradients in the stratum corneum at different treatment times by direct comparison of corresponding strips. While it does not appear that a penetrant’s deposition as a function of time can be followed easily and directly by stripping and then quantifying the drug (or solvent) in the respective layers, the stripping technique may still be useful in separating stratum comeum (or epidermis) from dermis.