The use of hepatocytes in evaluating time-dependent inactivation of P450in vivo

Abstract

Factors that may impact prediction accuracy, such as nonspecific binding, metabolism of inactivator, active transport, and sequential inhibitory metabolites, can be assessed by performing 'in vitro-in vitro' correlation between microsomes and hepatocytes. Together with microsomal data and the aid of computer modeling and simulation, hepatocytes provide a powerful tool to optimize the integrated approaches aimed at quantitatively predicting TDI in vivo.

Complex Drug Interactions of HIV Protease Inhibitors 1: Inactivation, Induction, and Inhibition of Cytochrome P450 3A by Ritonavir or Nelfinavir

“…This may be a result of varying contributions of the three points listed above for each inactivator. These observations are consistent with those of Zhao (2008), who showed differing inactivation potency (time-dependent inactivation IC 50 ) between HLMs and suspended human hepatocytes for amprenavir and erythromycin but not for diltiazem, raloxifene, or troleandomycin. This finding highlights the importance of using SCHHs to determine CYP3A inactivation because this model includes the canalicular efflux processes that may determine intracellular drug concentrations.…”

Time-Dependent Inhibition and Estimation of CYP3A Clinical Pharmacokinetic Drug-Drug Interactions Using Plated Human Cell Systems

“…The ideal in vitro system for comprehensively evaluating drug-drug interactions should theoretically be human hepatocytes (Zhao, 2008), given the full complement of metabolic clearance mechanisms. Even though the ability to conduct in vitro DDI studies has been demonstrated in human hepatocyte suspensions (Mao et al, 2011), there are limitations with the long-term viability and enzymatic activity of the cells in suspension (Zhao, 2008). It has been demonstrated that human plated cell systems offer unique advantages over human cell suspensions for time-dependent inhibition studies (Li and Doshi, 2011).…”

“…The process of using in vitro inactivation data to estimate and rank order the DDI potential of compounds is well established (Mayhew et al, 2000;Obach et al, 2006Obach et al, , 2007, and the in vitro inactivation kinetic parameters along with the in vivo systemic and intestinal concentration of the time-dependent inhibitor, fraction metabolized, and intestinal extraction ratio of the victim probe drug, and enzyme degradation rates (Correia, 1991;Greenblatt et al, 2003;Ghanbari et al, 2006) are used to estimate the potential for a clinical DDI (Obach et al, 2006(Obach et al, , 2007. However, precipitants of TDI are not always products of oxidative metabolism (Ogilvie et al, 2006;Baer et al, 2009;Xu et al, 2009;Honkalammi et al, 2011), and therefore it may be more relevant to assess TDI in a system containing the full complement of drug-metabolizing enzymes, such as hepatocytes (Li, 1997;Zhao et al, 2005;Zhao, 2008;Li and Doshi, 2011).…”

“…The use of hepatocytes for timedependent inhibition holds distinct advantages over the use of microsomes, including being more physiologically relevant and offering the ability to conduct longer incubations. However, there are some potential difficulties associated with time-dependent inhibition studies using hepatocyte suspensions, including removal of time-dependent inhibitor while maintaining cell viability (Zhao, 2008).…”

Functional ATP-Binding Cassette Drug Efflux Transporters in Isolated Human and Rat Hepatocytes Significantly Affect Assessment of Drug Disposition

“…Isolated hepatocytes are used to determine many properties of a candidate drug, its intrinsic clearance (CL int ), and metabolic pathways, and increasingly also to assess drug-drug interactions mediated by drug-metabolizing enzymes and/or drug transporters (Soars et al, 2007a(Soars et al, , 2009Zhao, 2008;Chiba et al, 2009;McGinnity et al, 2009;Brown et al, 2010;Giacomini et al, 2010).…”