Physiologically Based Kinetic Modelling (PBK) using QIVIVE to predict the toxicokinetic profiles of triazoles via oral route of administration

Physiologically Based Kinetic Modelling (PBK) using QIVIVE to predict the toxicokinetic profiles of triazoles via oral route of administration. — Abishek Laxmanan Ravi Shankar1,*, Jenny Irwan1, Max Spänig1, Anke Londenberg1, Maxim Carlier2, Timo Hamers2, Nicole Zümbulte3, Todd Gouin4, Patrik Lundquist5, Pawel Barenczewski5, Tanja Hansen1, Sylvia E. Escher1 1) Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM), Hannover, Germany; 2) Vrije Universiteit Amsterdam, Netherlands 3) DVGW-Technologiezentrum Wasser, Karlsruhe, Germany; 4) TG Environmental Research, United Kingdom; 5) Department of Pharmacy, Drug delivery, Uppsala University, Sweden 1 Fisher C et al ., VIVD: Virtual in vitro distribution model for the mechanistic prediction of intracellular concentrations of chemicals in in vitro toxicity assays. Toxicol in vitro. 2019 Aug; 58: 42-50. doi: 10.1016/j.tiv.2018.12.017. Epub 2018 Dec 29. PMID: 30599189. 2Maísa Daniela Habenschus (2019) et al., In vitro enantioselective study of the toxicokinetic effects of chiral fungicide tebuconazole in human liver microsomes, Ecotoxicology and Environmental Safety, Vol 181, pages 96 – 105, https://doi.org/10.1016/j.ecoenv.2019.05.071 3Mansouri, K et al., OPERA: A free and open source QSAR tool for predicting physicochemical properties and environmental fate endpoints. Presented at American Chemical Society Spring 2018, New Orleans, LA, March 18 - 22, 2018. 4ADMET Property Prediction | Machine Learning | AI-driven Drug Design (simulations-plus.com) 5 EFSA Draft Assessment Report (DAR) – public version. Initial risk assessment provided by the rapporteur Member State Denmark for the existing active substance – Tebuconazole (Vol 3, annex B, part 2/A, B.6 Nov 2007) 6 Williams AJ Wambaugh JF, Richard AM et al., The CompTox Chemistry Dashboard: a community data resource for environmental chemistry. J Cheminform. 2017 Nov 28;9(1):61. doi: 10.1186/s13321-017-0247-6 7 Predict Molecular Properties | Percepta Software | ACD/Labs (acdlabs.com) Proof of Concept: Tebuconazole rat based PBK Model Input parameters Values Intrinsic hepatic clearance (PHH) (µL/min/million cells) 3.625 ZeroPM 7.3 (RH3R) 5.6 (CompTox) Fraction Unbound 0.06 Apparent permeability (Papp) 38E-6 cm/s Model assumptions •Male rat body weight = 350 g •Input concentration = 2 mg/kg[5] •Radioactivity[5] is considered only for the parent compound and not for metabolites Data type Clint PHH = 3.62 [µl/min/million cells] In Vivo Data In vitro / In vivo C_max [µg/ml] 5.91 4.63 1.27 T_max [h] 7.11 1.53 4.64 AUC [µg/mL * h] 154.5 112.36 1.37 Fig 1 : Fraunhofer ITEM developed PBK Model Fig 2 : Tebuconazole rat based PBK model Background The ZeroPM is an EU funded project to develop a risk assessment framework for Persistent and Mobile (PM) compounds. Triazoles are PM compounds which are commonly used as pesticides. Aim Assess the toxicity of PM compounds using in vitro to in vivo extrapolation (QVIVE). Bottom up PBK model is developed to model the triazoles family parameterized using in vitro ADME assays and Read – Across approach. Approach: NAM data are derived from several in vitro assays testing mainly endocrine activity (Androgen hormone receptor , Estrogen hormone receptor, thyroid hormone receptor, TTR binding assay and H295R steroidogenisis). In vitro biokinetic modelling[1] is used to convert the EC20 value to the free unbound medium concentration. These values are compared to the human unbound plasma concentrations estimated form exposure and in vivo reference values. Presenting author*: Abishek Laxmanan Ravi Shankar ([email protected]) Human extrapolation assumptions •Route of exposure is oral via drinking water, administered 4 times a day, modelled for 100h Reference concentrations •Lowest observed adverse effect level (LOAEL) from in vivo rodent studies, scaled allometrically to human. LOAEL is used if LOAEL conc < Max solubility of the chemical •The maximum water solubility of the chemical is taken as the worst case input. •Exposure estimatemodelled concetration in ground water and surface water. Outcome •Human unbound plasma concentration (Cmax) from ground water and surface water is compared against LOAEL, maximum solubility and in vitro test assays. Read Across Approach (RAX) Summary and Results •A rat based PBK model is parameterized with the measured in vitro ADME values; namely intrinsic low metabolic clearance; permeability and fraction unbound. This simpletic model predicted a plasma concentration comparable to the rat in vivo plasma concentration. •Using QIVIVE the corrected free medium (EC20) concentrations from the NAM test battery are in the same range or lower compared to the values derived from the in vivo LOAEL values. The here used in vitro tests seem to be suitable to rank these compounds according to their toxicological properties. •The surface water and ground water derived unbound human plasma concentrations are about 100 – 1000 times smaller than those values derived from the in vitro/in vivo studies. Data rich Data poor •Estimate ADME properties like intrinsic hepatic clearance value from „data rich“ to „data poor“. •All the data rich compounds show low intrinsic clearance > Prediction is low clearance for all RAX compounds. df Fig 3: a) Difenoconazole b) Tebuconazole c) Tetraconazole d) Bitertanol e) Paclobutrazol f) Fenbuconazole – Maximum solubility limit vs in vitro endrocrine disruptors assay, LOAEL concentration vs surface and ground water concentration ab c This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 101036756. e Paclobutrazol Androgen receptor Antagonism –EC20 free medium Estrogen receptor Antagonism – EC20 free medium Thyroid receptor Antagonism – EC20 free medium TTR Binding Assay–EC20 free medium H295R Steroidogenesis – EC1.5 free medium Maximum Water Solubility LOAEL Concentration Surface water concentration Ground water concentration Estrogen Receptor Inactivity Thyroid Receptor Inactivity TTR Binding Assay Inactivity Legend