Disposition and metabolism of the bisphenol analogue, bisphenol S, in Harlan Sprague Dawley rats and B6C3F1/N mice and in vitro in hepatocytes from rats, mice, and humans

With the removal of bisphenol A (BPA) from many consumer products, the potential use of alternatives such as bisphenol S (BPS) and its derivatives is causing some concerns. These studies investigated the comparative in vitro hepatic clearance and metabolism of BPS and derivatives and the disposition and metabolism of BPS in rats and mice following gavage and intravenous administration. The clearance of BPS and its derivatives was slower in human hepatocytes than in rodents. In male rats following gavage administration of 50, 150, and 500 mg/kg [14C]BPS the main route of excretion was via urine; the urinary excretion decreased (72 to 48%) and the fecal excretion increased (16 to 30%) with increasing dose. The disposition was similar in female rats and male and female mice following gavage administration. Radioactivity remaining in tissues at 72 h in both species and sexes was ≤2.4%. In bile duct cannulated rats 53% of a gavage dose was secreted in bile suggesting extensive enterohepatic recirculation of [14C]BPS. Following an intravenous dose in rats and mice, the pattern of excretion was similar to gavage. These data suggest that the dose excreted in feces folowing gavage administration is likely the absorbed dose. Urinary metabolites included the glucuronide and sulfate conjugates with a moderate amount of parent. The pattern of in vitro hepatic metabolsim was similar to in vivo with some difference among derivatives. These data suggest that similar to other bisphenol analogues, BPS was well absorbed following oral expsosure and extensively excreted with minimal tissue retention.