IN-VITRO PERCUTANEOUS-ABSORPTION OF [C-14] ETHYLENE-GLYCOL

The objective of this study was to determine the percutaneous absorpti on of ethylene glycol through human skin in vitro. The in vitro diffus ion cells were of the flow-through design with 1 cm(2) surface area. T hree separate donor skin samples, taken from the thighs of white males , 16, 37, and 57 years old, were used and three replicates were perfor med for each experiment. Phosphate buffered saline, at a flow rate of three ml per hour, served as the receptor fluid. The human cadaver ski n samples were dermatomed to 500 mu m. [C-14]-labeled ethylene glycol was applied to the skin surface in acetone vehicle at a dose of 8 mu g /cm(2). After 24-hr dermal exposure, 18.28 +/- 5.02 % in the skin and 12.53 +/- 6.77 % in the skin surface wash (total accountability was 39 .11 +/- 7.23 %). Individual difference existed (P<0.05) for the three human skin sources. The combined skin and receptor fluid partitioning resulted in a potential absorbed dose of 26.57% relative to the 8 mu g /cm(2) applied dose for a 24-hr exposure duration. This represents a f lux of approximately 2 mu g/cm(2)/24 hr or 0.09 mu g/cm(2)/hr for ethy lene glycol. The maximum flux observed was 2.82%/hr/cm(2) or 0.25 mu g /cm(2)/hr.