In vivo and In vitro Dermal Penetration of 2,4,5,2',4',5'-Hexachlorobiphenyl in Young and Adult Rate

摘要

Penetration of (14)C-2,4,5,2',4',5'-hexachlorobiphenyl (HCB) through skin of young (33 days) and adults (82 days) female Fischer 344 rats was determined in vivo and by two in vitro methods. In vivo dermal penetration at 120 hours was 45% in young and 43% in adults. At 72 hours in vivo dermal penetration was 35% in young and 26% in adults compared to 1.3% for young and 1.4% for adult as measured with a continuous flow in vitro system and 2.5% for young and 1.2% for adults as measured with a static in vitro system. Most of the absorbed HCB remained in the body as only 4.9% and 2.6% of that absorbed was excreted by young and adult rats respectively by 120 hours. The excretion of HCB in feces was approximately six times higher than into urine. A physiological pharmacokinetic model was fit to the organ and tissue distribution data. Parameters in the model determined from dermal dosing of female Fischer-344 rats were in reasonable agreement with those obtained from i.v. dosing of adult male Sprague Dawley rats. Differences in the model parameters between young and adult rats were found. (Copyright (c) 1989 by Academic Press, Inc.)