How Does the In Vivo Biliary Elimination of Drugs Change with Age? Evidence from In Vitro and Clinical Data Using a Systems Pharmacology Approach

Information on the developmental changes in biliary excretion (BE) of drugs is sparse. The aims of this study were to collate literature data on the pharmacokinetics of biliary excretion of drugs used in pediatrics and to apply a physiologically-based pharmacokinetic (PBPK) model to predict their systemic clearance (CL) with a view to elucidating age-related changes […]

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More Power to OATP1B1: An Evaluation of Sample Size in Pharmacogenetic Studies Using a Rosuvastatin PBPK Model for Intestinal, Hepatic and Renal Transporter-mediated Clearances

Rosuvastatin is a substrate of choice in clinical studies of organic anion-transporting polypeptide (OATP)1B1- and OATP1B3-associated drug interactions; thus, understanding the effect of OATP1B1 polymorphisms on the pharmacokinetics of rosuvastatin is crucial. Here, physiologically-based pharmacokinetic (PBPK) modeling was coupled with a power calculation algorithm to evaluate the influence of sample size on the ability to […]

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Drug-drug Interactions and QT Prolongation as a Commonly Assessed Cardiac Effect – Comprehensive Overview of Clinical Trials

Proarrhythmia assessment is one of the major concerns for regulatory bodies and pharmaceutical industry. ICH guidelines recommending preclinical tests have been established in attempt to eliminate the risk of drug-induced arrhythmias. However, in the clinic, arrhythmia occurrence is determined not only by the inherent property of a drug to block ion currents and disturb electrophysiological […]

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Considering Age Variation When Coining Drugs as High versus Low Hepatic Extraction Ratio

The hepatic extraction ratio (EH) is commonly considered an “inherent attribute” of drug. It determines the main physiological and biological elements of the system (patient attributes) that are most significant in interindividual variability of clearance. The EH consists of three age-dependent parameters: fraction of unbound drug in blood (fu.B), hepatic intrinsic clearance of unbound drug […]

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Prediction of Drug-drug Interactions Arising From CYP3A Induction Using a Physiologically-based Dynamic Model

Using physiologically-based pharmacokinetic modeling, we predicted the magnitude of drug-drug interactions (DDIs) for studies with rifampicin and seven CYP3A4 probe substrates administered i.v. (10 studies) or orally (19 studies). The results showed a tendency to underpredict the DDI magnitude when the victim drug was administered orally. Possible sources of inaccuracy were investigated systematically to determine […]

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Potential Sources of Inter-subject Variability in Monoclonal Antibody Pharmacokinetics

Understanding inter-subject variability in drug pharmacokinetics and pharmacodynamics is important to ensure that all patients attain suitable drug exposure to achieve efficacy and avoid toxicity. Inter-subject variability in the pharmacokinetics of therapeutic monoclonal antibodies (mAbs) is generally moderate to high; however, the factors responsible for the high inter-subject variability have not been comprehensively reviewed. In […]

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Metformin and Cimetidine: Physiologically-based Pharmacokinetic Modeling to Investigate Transporter Mediated Drug-drug Interactions

Metformin is used as a probe for OCT2 mediated transport when investigating possible DDIs with new chemical entities. The aim of the current study was to investigate the ability of physiologically–based pharmacokinetic (PBPK) models to simulate the effects of OCT and MATE inhibition by cimetidine on metformin kinetics. PBPK models were developed, incorporating mechanistic kidney […]

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Recent Advances in Development and Application of Physiologically-based Pharmacokinetic (PBPK) Models: A Transition from Academic Curiosity to Regulatory Acceptance

There is a renewed surge of interest in applications of physiologically-based pharmacokinetic (PBPK) models by the pharmaceutical industry and regulatory agencies. Developing PBPK models within a systems pharmacology context allows separation of the parameters pertaining to the animal or human body (the system) from that of the drug and the study design which is essential to develop […]

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Development of a Permeability-limited Model of the Human Brain and Cerebrospinal Fluid (CSF) to Integrate Known Physiological and Biological Knowledge: Estimating Time Varying CSF Drug Concentrations and Their Variability Using In Vitro Data

A 4-compartment permeability-limited brain (4Brain) model consisting of brain blood, brain mass, cranial and spinal cerebrospinal fluid (CSF) compartments has been developed and incorporated into a whole body physiologically-based pharmacokinetic (PBPK) model within the Simcyp Simulator. The model assumptions, structure, governing equations and system parameters are described. The model in particular considers the anatomy and […]

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Status of QSP Modeling in the Pharmaceutical Industry

Steve Toon

A primary cause of failures in pharmaceutical research and development (R&D) has been attributed to lack of efficacy1, suggesting inadequate understanding in therapeutic targets’ biology and their relevance to disease progression or modulation. Quantitative systems pharmacology (QSP) has the promise of increasing the probability of success in R&D by bridging scientific gaps between disciplines to […]

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Topics: Drug Safety, Model-based Drug Development, PBPK Modeling and Simulation

More Power to OATP1B1: An Evaluation of Sample Size in Pharmacogenetic Studies Using a Rosuvastatin PBPK Model for Intestinal, Hepatic, and Renal Transporter-mediated Clearances

Rosuvastatin is a substrate of choice in clinical studies of organic anion-transporting polypeptide (OATP)1B1- and OATP1B3-associated drug interactions; thus, understanding the effect of OATP1B1 polymorphisms on the pharmacokinetics of rosuvastatin is crucial. Here, physiologically based pharmacokinetic (PBPK) modeling was coupled with a power calculation algorithm to evaluate the influence of sample size on the ability to detect an […]

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Metformin and cimetidine: Physiologically based pharmacokinetic modeling to investigate transporter mediated drug-drug interactions.

Metformin is used as a probe for OCT2 mediated transport when investigating possible DDIs with new chemical entities. The aim of the current study was to investigate the ability of physiologically-based pharmacokinetic (PBPK) models to simulate the effects of OCT and MATE inhibition by cimetidine on metformin kinetics. PBPK models were developed, incorporating mechanistic kidney and […]

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Getting at the HAART of Precision Dosing: Using PBPK Models to Optimize Dosing of an Antiviral

Efavirenz is a non-nucleoside reverse transcriptase inhibitor (NNRTI) used as part of highly active antiretroviral therapy (HAART) for the treatment of a human immunodeficiency virus (HIV) type 1. It is primarily metabolized by CY2B6. A standard dose of efavirenz has been associated with serious adverse reactions in poor metabolizers (PMs) of CYP2B6, necessitating a reduction […]

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SIVA Toolkit V2: Simcyp In Vitro Analysis Toolkit

The SIVA Toolkit is a user-friendly platform, specifically designed to assist scientists with the analysis of complex in vitro studies using whole cells, tissue samples and solid dosage forms to assess the metabolism, transport and dissolution/solubility of drugs. SIVA combines the latest model-based data analysis approaches with powerful optimization algorithms in a sophisticated statistical environment.

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