| 1. |
- Abrahamsson, B., et al.
(författare)
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Six years of progress in the oral biopharmaceutics area - A summary from the IMI OrBiTo project
- 2020
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Ingår i: European journal of pharmaceutics and biopharmaceutics. - : ELSEVIER. - 0939-6411 .- 1873-3441. ; 152, s. 236-247
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Tidskriftsartikel (refereegranskat)abstract
- OrBiTo was a precompetitive collaboration focused on the development of the next generation of Oral Biopharmaceutics Tools. The consortium included world leading scientists from nine universities, one regulatory agency, one non-profit research organisation, three small/medium sized specialist technology companies together with thirteen pharmaceutical companies. The goal of the OrBiTo project was to deliver a framework for rational application of predictive biopharmaceutics tools for oral drug delivery. This goal was achieved through novel prospective investigations to define new methodologies or refinement of existing tools. Extensive validation has been performed of novel and existing biopharmaceutics tools using historical datasets supplied by industry partners as well as laboratory ring studies. A combination of high quality in vitro and in vivo characterizations of active drugs and formulations have been integrated into physiologically based in silico biopharmaceutics models capturing the full complexity of gastrointestinal drug absorption and some of the best practices has been highlighted. This approach has given an unparalleled opportunity to deliver transformational change in European industrial research and development towards model based pharmaceutical product development in accordance with the vision of model-informed drug development.
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| 2. |
- Lennernäs, Hans, et al.
(författare)
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Oral biopharmaceutics tools - Time for a new initiative - An introduction to the IMI project OrBiTo
- 2014
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Ingår i: European Journal of Pharmaceutical Sciences. - : Elsevier BV. - 0928-0987 .- 1879-0720. ; 57:SI, s. 292-299
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Forskningsöversikt (refereegranskat)abstract
- OrBiTo is a new European project within the IMI programme in the area of oral biopharmaceutics tools that includes world leading scientists from nine European universities, one regulatory agency, one non-profit research organization, four SMEs together with scientists from twelve pharmaceutical companies. The OrBiTo project will address key gaps in our knowledge of gastrointestinal (GI) drug absorption and deliver a framework for rational application of predictive biopharmaceutics tools for oral drug delivery. This will be achieved through novel prospective investigations to define new methodologies as well as refinement of existing tools. Extensive validation of novel and existing biopharmaceutics tools will be performed using active pharmaceutical ingredient (API), formulations and supporting datasets from industry partners. A combination of high quality in vitro or in silico characterizations of API and formulations will be integrated into physiologically based in silica biopharmaceutics models capturing the full complexity of GI drug absorption. This approach gives an unparalleled opportunity to initiate a transformational change in industrial research and development to achieve model-based pharmaceutical product development in accordance with the Quality by Design concept. Benefits include an accelerated and more efficient drug candidate selection, formulation development process, particularly for challenging projects such as low solubility molecules (BCS II and IV), enhanced and modified-release formulations, as well as allowing optimization of clinical product performance for patient benefit. In addition, the tools emerging from OrBiTo are expected to significantly reduce demand for animal experiments in the future as well as reducing the number of human bioequivalence studies required to bridge formulations after manufacturing or composition changes.
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| 3. |
- Darwich, A. S., et al.
(författare)
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Interplay of Metabolism and Transport in Determining Oral Drug Absorption and Gut Wall Metabolism : A Simulation Assessment Using the "Advanced Dissolution, Absorption, Metabolism (ADAM)" Model
- 2010
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Ingår i: Current drug metabolism. - : Bentham Science Publishers Ltd.. - 1389-2002 .- 1875-5453. ; 11:9, s. 716-729
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Forskningsöversikt (refereegranskat)abstract
- Bioavailability of orally administered drugs can be influenced by a number of factors including release from the formulation, dissolution, stability in the gastrointestinal (GI) environment, permeability through the gut wall and first-pass gut wall and hepatic metabolism. Although there are various enzymes in the gut wall which may contribute to gut first pass metabolism, Cytochrome P450 (CYP) 3A has been shown to play a major role. The efflux transporter P-glycoprotein (P-gp; MDR1/ABCB1) is the most extensively studied drug efflux transporter in the gut and might have a significant role in the regulation of GI absorption. Although not every CYP3A substrate will have a high extent of gut wall first-pass extraction, being a substrate for the enzyme increases the likelihood of a higher first-pass extraction. Similarly, being a P-gp substrate does not necessarily pose a problem with the gut wall absorption however it may reduce bioavailability in some cases (e. g. when drug has low passive permeability). An on-going debate has focused on the issue of the interplay between CYP3A and P-gp such that high affinity to P-gp increases the exposure of drug to CYP3A through repeated cycling via passive diffusion and active efflux, decreasing the fraction of drug that escapes first pass gut metabolism (F-G). The presence of P-gp in the gut wall and the high affinity of some CYP3A substrates to this transporter are postulated to reduce the potential for saturating the enzymes, thus increasing gut wall first-pass metabolism for compounds which otherwise would have saturated CYP3A. Such inferences are based on assumptions in the modelling of oral drug absorption. These models should be as mechanistic as possible and tractable using available in vitro and in vivo information. We review, through simulation, this subject and examine the interplay between gut wall metabolism and efflux transporters by studying the fraction of dose absorbed into enterocytes (F-a) and F-G via systematic variation of drug characteristics, in accordance with the Biopharmaceutics Classification System (BCS) within one of the most physiological models of oral drug absorption currently available, respectively ADAM. Variables studied included the intrinsic clearance (CLint) and the Michaelis-Menten Constant (K-m) for CYP3A4 and P-gp (CLint-CYP3A4 and Km-CYP3A4, CLint-P-gp and Km-P-gp). The impact of CYP3A4 and P-gp intracellular topography were not investigated since a well-stirred enterocyte is assumed within ADAM. An increased CLint-CYP3A4 resulted in a reduced F-G whereas an increase in CLint-P-gp resulted in a reduced F-a, but interestingly decreased F-G too. The reduction in F-G was limited to certain conditions and was modest. Non-linear relationships between various parameters determining the permeability (e. g. P-app, CLint-P-gp, and Km-P-gp) and gut wall metabolism (e. g. CLint-CYP3A4, Km-CYP3A4) resulted in disproportionate changes in F-G compared to the magnitude of singular effects. The results suggest that P-gp efflux decreases enterocytic drug concentration for drugs given at reasonably high dose which possess adequate passive apparent permeability (high P-app), by de-saturating CYP3A4 in the gut resulting in a lower F-G. However, these findings were observed only in a very limited area of the parameters space matching very few herapeutic drugs (a group with very high metabolism, high turn-over by efflux transporters and low F-a). The systematic approach in this study enabled us to recognise the combination of parameter values where the potential interplay between metabolising enzymes and efflux transporters is expected to be highest, using a realistic range of parameter values taken from an intensive literature search.
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| 4. |
- Prasad, Bhagwat, et al.
(författare)
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Toward a Consensus on Applying Quantitative Liquid Chromatography-Tandem Mass Spectrometry Proteomics in Translational Pharmacology Research : A White Paper
- 2019
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Ingår i: Clinical Pharmacology and Therapeutics. - : WILEY. - 0009-9236 .- 1532-6535. ; 106:3, s. 525-543
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Tidskriftsartikel (refereegranskat)abstract
- Quantitative translation of information on drug absorption, disposition, receptor engagement, and drug-drug interactions from bench to bedside requires models informed by physiological parameters that link in vitro studies to in vivo outcomes. To predict in vivo outcomes, biochemical data from experimental systems are routinely scaled using protein quantity in these systems and relevant tissues. Although several laboratories have generated useful quantitative proteomic data using state-of-the-art mass spectrometry, no harmonized guidelines exit for sample analysis and data integration to in vivo translation practices. To address this gap, a workshop was held on September 27 and 28, 2018, in Cambridge, MA, with 100 experts attending from academia, the pharmaceutical industry, and regulators. Various aspects of quantitative proteomics and its applications in translational pharmacology were debated. A summary of discussions and best practices identified by this expert panel are presented in this "White Paper" alongside unresolved issues that were outlined for future debates.
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| 5. |
- Brussee, Janneke M., et al.
(författare)
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Characterization of Intestinal and Hepatic CYP3A-Mediated Metabolism of Midazolam in Children Using a Physiological Population Pharmacokinetic Modelling Approach
- 2018
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Ingår i: Pharmaceutical research. - : Springer. - 0724-8741 .- 1573-904X. ; 35:9
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Changes in drug absorption and first-pass metabolism have been reported throughout the pediatric age range. Our aim is to characterize both intestinal and hepatic CYP3A-mediated metabolism of midazolam in children in order to predict first-pass and systemic metabolism of CYP3A substrates. Methods Pharmacokinetic (PK) data of midazolam and 1-OH-midazolam from 264 post-operative children 1-18 years of age after oral administration were analyzed using a physiological population PK. modelling approach. In the model, consisting of physiological compartments representing the gastro-intestinal tract and liver,intrinsic intestinal and hepatic clearances were estimated to derive values for bioavailability and plasma clearance. Results The whole-organ intrinsic clearance in the gut wall and liver were found to increase with body weight, with a 105 (95% confidence interval (CI): 5-405) times lower intrinsic gut wall clearance than the intrinsic hepatic dearance (i.e. 5.08 L/h (relative standard error (RSE) 10%) versus 527 L/h (RSE 7%) for a 16 kg individual, respectively). When expressed per gram of organ, intrinsic clearance increases with increasing body weight in the gut wall, but decreases in the liver, indicating that CYP3A-mediated intrinsic clearance and local bioavailability in the gut wall and liver do not change with age in parallel. The resulting total bioavailability was found to be age-independent with a median of 20.8% in children (95%CI: 3.8-50.0%). Conclusion In conclusion, the intrinsic CYP3A-mediated gut wall clearance is substantially lower than the intrinsic hepatic CYP3A-mediated clearance in children from 1 to 18 years of age, and contributes less to the overall first-pass metabolism compared to adults.
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| 6. |
- Brussee, Janneke M., et al.
(författare)
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First-Pass CYP3A-Mediated Metabolism of Midazolam in the Gut Wall and Liver in Preterm Neonates
- 2018
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Ingår i: CPT. - : WILEY. - 2163-8306. ; 7:6, s. 374-383
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Tidskriftsartikel (refereegranskat)abstract
- To predict first-pass and systemic cytochrome P450 (CYP) 3A-mediated metabolism of midazolam in preterm neonates, a physiological population pharmacokinetic model was developed describing intestinal and hepatic midazolam clearance in preterm infants. On the basis of midazolam and 1-OH-midazolam concentrations from 37 preterm neonates (gestational age 26-34 weeks) receiving midazolam orally and/or via a 30-minute intravenous infusion, intrinsic clearance in the gut wall and liver were found to be very low, with lower values in the gut wall (0.0196 and 6.7 L/h, respectively). This results in a highly variable and high total oral bioavailability of 92.1% (range, 67-95%) in preterm neonates, whereas this is around 30% in adults. This approach in which intestinal and hepatic clearance were separately estimated shows that the high bioavailability in preterm neonates is explained by, likely age-related, low CYP3A activity in the liver and even lower CYP3A activity in the gut wall.
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| 7. |
- El-Khateeb, Eman, et al.
(författare)
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Using Prior Knowledge on Systems Through PBPK to Gain Further Insight into Routine Clinical Data on Trough Concentrations: The Case of Tacrolimus in Chronic Kidney Disease
- 2023
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Ingår i: Therapeutic Drug Monitoring. - : Ovid Technologies (Wolters Kluwer Health). - 0163-4356 .- 1536-3694. ; 45:6, s. 743-753
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Tidskriftsartikel (refereegranskat)abstract
- Background: Routine therapeutic drug monitoring (TDM) relies heavily on measuring trough drug concentrations. Trough concentrations are affected not only by drug bioavailability and clearance, but also by various patient and disease factors and the volume of distribution. This often makes interpreting differences in drug exposure from trough data challenging. This study aimed to combine the advantages of top-down analysis of therapeutic drug monitoring data with bottom-up physiologically-based pharmacokinetic (PBPK) modeling to investigate the effect of declining renal function in chronic kidney disease (CKD) on the nonrenal intrinsic metabolic clearance (CLint) of tacrolimus as a case example.Methods: Data on biochemistry, demographics, and kidney function, along with 1167 tacrolimus trough concentrations for 40 renal transplant patients, were collected from the Salford Royal Hospital's database. A reduced PBPK model was developed to estimate CLint for each patient. Personalized unbound fractions, blood-to-plasma ratios, and drug affinities for various tissues were used as priors to estimate the apparent volume of distribution. Kidney function based on the estimated glomerular filtration rate (eGFR) was assessed as a covariate for CLint using the stochastic approximation of expectation and maximization method.Results: At baseline, the median (interquartile range) eGFR was 45 (34.5-55.5) mL/min/1.73 m2. A significant but weak correlation was observed between tacrolimus CLint and eGFR (r = 0.2, P < 0.001). The CLint declined gradually (up to 36%) with CKD progression. Tacrolimus CLint did not differ significantly between stable and failing transplant patients.Conclusions: Kidney function deterioration in CKD can affect nonrenal CLint for drugs that undergo extensive hepatic metabolism, such as tacrolimus, with critical implications in clinical practice. This study demonstrates the advantages of combining prior system information (via PBPK) to investigate covariate effects in sparse real-world datasets.
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| 8. |
- Vicini, P, et al.
(författare)
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Pharmacometrics and Systems Pharmacology Software Tutorials and Use : Comments and Guidelines for PSP Contributions
- 2013
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Ingår i: CPT. - : Wiley. - 2163-8306. ; 2, s. e86-
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Tidskriftsartikel (refereegranskat)abstract
- In addition to methodological Tutorials,(1) CPT:PSP has recently started to publish software Tutorials.(2,3) Our readership and authors may be wondering what kind of format or product is expected, and the review of submissions we have already received prompted several discussions within the PSP Editorial Team. This editorial reflects on these discussions and summarizes their salient points. It aims at providing some details about the current vision of CPT:PSP for software tutorial articles. In addition, it brings some clarity on the topic of what role commercial software tutorials can have in CPT:PSP and how CPT:PSP tutorials differ from publications which describe the software itself, as those which can be found in other computer science journals. Finally, the discussion includes reproducibility considerations and the general use of commercial and noncommercial software in CPT:PSP publications. We hope our thoughts, and especially a stated requirement to publish user input to the software to aid in reproducibility, will help in guiding our authors and will stimulate healthy debate among our readers about the evolving nature of our science, how it can be facilitated using software and associated databases as a conduit, and what role this journal can play in fostering both the best modeling and simulation practices and the best scientific approaches to computational modeling, to bring the advantages of modeling and simulation to all regular practitioners, and not to just a (self) selected few.
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