Quantification of Bisphenol A in Swiss albino mice following topical exposure

Bisphenol A (BPA) is an industrial chemical used in plastics, resin-based food packaging, and thermal papers etc. BPA is reported as an endocrine disruptor and implicated in many disorders including infertility, diabetes, neurological, obesity, and cancer. The populace comes in contact with BPA through oral, inhalation, and dermal routes as it leaches out of the finished products. The present study is aimed to determine the levels of absorption through the skin as well as the penetration rate of BPA into the circulation following dermal exposure in Swiss albino mice. We used ultra-performance liquid chromatography with fluorescence detector to quantify the un-conjugated BPA in the serum and skin samples collected at 6 h, 12 h, 24 h, 48 h, 72 h, and 168 h from Swiss albino mice exposed to 250 mg/kg bw BPA through a single dermal application. Mean serum unconjugated BPA Cmax of 745 ng/mL was observed at 24 h. Unconjugated BPA appeared in serum 562 ng/mL within 6 h and was detected till 72 h at concentrations near the LOD (3.9 ng/mL) while those in skin samples unconjugated BPA is detectable at all the time points and displayed a gradual decrease in BPA concentration with progressing dura-tion post dermal exposure. Our study showed a slow absorption rate of BPA through the skin into the circulation and greater bioavailability of unconjugated BPA as it bypasses the first-pass metabolism, resulting in prolonged retention in the system with delayed elimination on dermal exposure.