Comparative dermal absorption of iodophenol (IO) by in vitro and in vivo methods in the rat

The purpose of the study was to compare the in vitro and in vivo dermal absorption of IO in female Fischer 344 rats. The clipped dorsal side was treated with 14C-IO (4 ug/cm2) and occluded. Urine and feces were collected at timed intervals up to 120 hr. At 24 hr, 53.8 ± 2.0% (mean ± SE, N=4) of the dose was excreted in the urine, < 1% excreted in the feces. At 120 hr, 65.4 ± 1.5% of the dose was excreted in the urine, 1.3 ± 0.1% in the feces and 6.1 ± 1.8% remained in the skin. A two compartment model was fit to the urinary excretion data. In vitro absorption was determined by both the flow-through and static systems. Clipped dorsal skin was dermatomed to 350 um and treated with 14C-IO (4 ug/cm2) and occluded. At 24 hr, 65.3 ± 7.0% (N=9) of the dose had penetrated the skin of the flow-through system and 65.2 ± 4.9% (N=6) in the static system. This data is in good agreement with the 24 hr urine and fecal excretion data. The use of in vitro systems may aid in the development of risk assessment for dermal exposure to chemicals