Evaluation of pharmacokinetic interactions between bicyclol and co-administered drugs in rat and human liver microsomes in vitro and in rats in vivo

Abstract

Bicyclol is a new synthetic anti-hepatitic drug and primarily metabolized by CYP3A. The aim of this study was to evaluate the pharmacokinetic interactions between bicyclol and co-administered drugs including metformin, pioglitazone, atorvastatin, fenofibrate, Cyclosporin A (CsA), and tacrolimus in rat and human liver microsomes (RLMs/HLMs) in vitro and in rats in vivo.The depletion rate of bicyclol in RLMs was significantly inhibited by 44.8% and 35.5% after preincubation with pioglitazone and fenofibrate while the metabolite formation rate of bicyclol in HLMs was inhibited by 26.1% and 23.9% after preincubation and coincubation with tacrolimus, and by 20.2% after preincubation with CsA. Conversely, preincubation and coincubation with bicyclol significantly inhibited the depletion rate of pioglitazone in RLMs by 34.1% and 27.1%, respectively, and the formation rate of para- and ortho-hydroxy atorvastatin in RLMs and HLMs by 20.6–36.2%. There were no significant pharmacokinetic interactions between bicyclol and pioglitazone in rats after a single or multiple oral treatment.As the selected inhibitory drug concentrations in vitro were significantly higher than those in clinical settings and the maximum inhibition rate did not exceed 50%, the clinically significant interaction between bicyclol and these co-administered drugs in humans is predicted less likely to happen.