Non-Clinical Development-Drug Safety, F. Hoffmann-La Roche Ltd., Basel, Switzerland.
J Pharmacokinet Pharmacodyn. 2009 Dec;36(6):585-611. doi: 10.1007/s10928-009-9139-3. Epub 2009 Nov 20.
The aim of this study was to evaluate a strategy based on a physiologically based pharmacokinetic (PBPK) model for the prediction of PK profiles in human using in vitro data when elimination of compounds relies on active transport processes. The strategy was first applied to rat in vivo and in vitro data in order to refine the PBPK model. The model could then be applied to human in vitro uptake transport data using valsartan as a probe substrate. Plated rat and human hepatocytes, and cell lines overexpressing human OATP1B1 and OATP1B3 were used for in vitro uptake experiments. The uptake rate of valsartan was higher for rat hepatocytes (K (m,u) = 28.4 +/- 3.7 muM, V (max) = 1318 +/- 176 pmol/mg/min and P (dif) = 1.21 +/- 0.42 microl/mg/min) compared to human hepatocytes (K (m,u) = 44.4 +/- 14.6 microM, V (max) = 304 +/- 85 pmol/mg/min and P (dif) = 0.724 +/- 0.271 microl/mg/min). OATP1B1 and 1B3 parameters were correlated to human hepatocyte data using experimentally established relative activity factors (RAF). Resulting PBPK simulations using those in vitro data were compared for plasma (human and rat) and bile (rat) concentration-time profiles following i.v. bolus administration of valsartan. An uncertainty analysis indicated that the scaled in vitro uptake clearance had to be adjusted with an additional empirical scaling factor of 5 to match the plasma concentrations and biliary excretion profiles. Applying this model, plasma clearances (CL(P)) for rat and human were predicted within two-fold relative to predictions based on respective in vitro data. The corrected hepatic uptake transport kinetic parameters enabled the prediction of valsartan in vivo PK profiles and plasma clearances, using PBPK modeling. Moreover, the interspecies difference in elimination rate observed in vivo was correctly reflected in the transport parameters determined in vitro. More data are needed to support more general applications of the proposed approach including its use for metabolized compounds.
本研究旨在评估一种基于生理药代动力学（PBPK）模型的策略，该策略可利用体外数据预测化合物消除依赖主动转运过程时的 PK 特征。首先将该策略应用于大鼠体内和体外数据，以优化 PBPK 模型。然后，可将该模型应用于人类体外摄取转运数据，以缬沙坦作为探针底物。使用原代大鼠和人肝细胞以及过表达人 OATP1B1 和 OATP1B3 的细胞系进行体外摄取实验。与人肝细胞相比，大鼠肝细胞对缬沙坦的摄取速率更高（K(m,u) = 28.4 +/- 3.7 muM，V(max) = 1318 +/- 176 pmol/mg/min 和 P(dif) = 1.21 +/- 0.42 microl/mg/min）（K(m,u) = 44.4 +/- 14.6 microM，V(max) = 304 +/- 85 pmol/mg/min 和 P(dif) = 0.724 +/- 0.271 microl/mg/min）。使用实验确定的相对活性因子（RAF）将 OATP1B1 和 1B3 参数与人类肝细胞数据相关联。使用这些体外数据进行的 PBPK 模拟比较了静脉内推注缬沙坦后大鼠和人血浆（人和大鼠）和胆汁（大鼠）浓度-时间曲线。不确定性分析表明，必须通过额外的经验缩放因子 5 调整体外摄取清除率，以匹配血浆浓度和胆汁排泄曲线。应用该模型，大鼠和人类的血浆清除率（CL(P)）与基于各自体外数据的预测值相差不到两倍。校正后的肝摄取转运动力学参数可用于预测缬沙坦的体内 PK 特征和使用 PBPK 模型预测的血浆清除率。此外，在体内观察到的消除率种间差异在体外确定的转运参数中得到了正确反映。需要更多的数据来支持该方法的更广泛应用，包括其在代谢化合物中的应用。
