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Spreitzer I, Keife J, Strasser T, Kalaba P, Lubec J, Neuhaus W, Lubec G, Langer T, Wackerlig J, Loryan I. Pharmacokinetics of Novel Dopamine Transporter Inhibitor CE-123 and Modafinil with a Focus on Central Nervous System Distribution. Int J Mol Sci 2023; 24:16956. [PMID: 38069277 PMCID: PMC10707468 DOI: 10.3390/ijms242316956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 11/24/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
S-CE-123, a novel dopamine transporter inhibitor, has emerged as a potential candidate for cognitive enhancement. The objective of this study was to compare the tissue distribution profiles, with a specific focus on central nervous system distribution and metabolism, of S-CE-123 and R-modafinil. To address this objective, a precise liquid chromatography-high resolution mass spectrometry method was developed and partially validated. Neuropharmacokinetic parameters were assessed using the Combinatory Mapping Approach. Our findings reveal distinct differences between the two compounds. Notably, S-CE-123 demonstrates a significantly superior extent of transport across the blood-brain barrier (BBB), with an unbound brain-to-plasma concentration ratio (Kp,uu,brain) of 0.5, compared to R-modafinil's Kp,uu,brain of 0.1. A similar pattern was observed for the transport across the blood-spinal cord barrier. Concerning the drug transport across cellular membranes, we observed that S-CE-123 primarily localizes in the brain interstitial space, whereas R-modafinil distributes more evenly across both sides of the plasma membrane of the brain's parenchymal cells (Kp,uu,cell). Furthermore, our study highlights the substantial differences in hepatic metabolic stability, with S-CE-123 having a 9.3-fold faster metabolism compared to R-modafinil. In summary, the combination of improved BBB transport and higher affinity of S-CE-123 to dopamine transporters in comparison to R-modafinil makes S-CE-123 a promising candidate for further testing for the treatment of cognitive decline.
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Affiliation(s)
- Iva Spreitzer
- Department of Pharmaceutical Sciences, University of Vienna, 1090 Vienna, Austria; (I.S.); (T.L.)
- Vienna Doctoral School of Pharmaceutical, Nutritional and Sport Sciences, University of Vienna, 1090 Vienna, Austria
| | - Josefin Keife
- Translational Pharmacokinetics/Pharmacodynamics Group, Department of Pharmacy, Uppsala University, 75123 Uppsala, Sweden
| | - Tobias Strasser
- Department of Pharmaceutical Sciences, University of Vienna, 1090 Vienna, Austria; (I.S.); (T.L.)
| | - Predrag Kalaba
- Department of Pharmaceutical Sciences, University of Vienna, 1090 Vienna, Austria; (I.S.); (T.L.)
| | - Jana Lubec
- Programme for Proteomics, Paracelsus Medical University, 5020 Salzburg, Austria (G.L.)
| | - Winfried Neuhaus
- Competence Unit Molecular Diagnostics, Center Health and Bioresources, AIT Austrian Institute of Technology GmbH, 1210 Vienna, Austria;
- Department of Medicine, Faculty of Medicine and Dentistry, Danube Private University, 3500 Krems, Austria
| | - Gert Lubec
- Programme for Proteomics, Paracelsus Medical University, 5020 Salzburg, Austria (G.L.)
| | - Thierry Langer
- Department of Pharmaceutical Sciences, University of Vienna, 1090 Vienna, Austria; (I.S.); (T.L.)
| | - Judith Wackerlig
- Department of Pharmaceutical Sciences, University of Vienna, 1090 Vienna, Austria; (I.S.); (T.L.)
| | - Irena Loryan
- Translational Pharmacokinetics/Pharmacodynamics Group, Department of Pharmacy, Uppsala University, 75123 Uppsala, Sweden
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Loryan I, Reichel A, Feng B, Bundgaard C, Shaffer C, Kalvass C, Bednarczyk D, Morrison D, Lesuisse D, Hoppe E, Terstappen GC, Fischer H, Di L, Colclough N, Summerfield S, Buckley ST, Maurer TS, Fridén M. Unbound Brain-to-Plasma Partition Coefficient, K p,uu,brain-a Game Changing Parameter for CNS Drug Discovery and Development. Pharm Res 2022; 39:1321-1341. [PMID: 35411506 PMCID: PMC9246790 DOI: 10.1007/s11095-022-03246-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/22/2022] [Indexed: 12/11/2022]
Abstract
PURPOSE More than 15 years have passed since the first description of the unbound brain-to-plasma partition coefficient (Kp,uu,brain) by Prof. Margareta Hammarlund-Udenaes, which was enabled by advancements in experimental methodologies including cerebral microdialysis. Since then, growing knowledge and data continue to support the notion that the unbound (free) concentration of a drug at the site of action, such as the brain, is the driving force for pharmacological responses. Towards this end, Kp,uu,brain is the key parameter to obtain unbound brain concentrations from unbound plasma concentrations. METHODS To understand the importance and impact of the Kp,uu,brain concept in contemporary drug discovery and development, a survey has been conducted amongst major pharmaceutical companies based in Europe and the USA. Here, we present the results from this survey which consisted of 47 questions addressing: 1) Background information of the companies, 2) Implementation, 3) Application areas, 4) Methodology, 5) Impact and 6) Future perspectives. RESULTS AND CONCLUSIONS From the responses, it is clear that the majority of the companies (93%) has established a common understanding across disciplines of the concept and utility of Kp,uu,brain as compared to other parameters related to brain exposure. Adoption of the Kp,uu,brain concept has been mainly driven by individual scientists advocating its application in the various companies rather than by a top-down approach. Remarkably, 79% of all responders describe the portfolio impact of Kp,uu,brain implementation in their companies as 'game-changing'. Although most companies (74%) consider the current toolbox for Kp,uu,brain assessment and its validation satisfactory for drug discovery and early development, areas of improvement and future research to better understand human brain pharmacokinetics/pharmacodynamics translation have been identified.
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Affiliation(s)
- Irena Loryan
- Department of Pharmacy, Uppsala University, Box 580, Uppsala, Sweden.
| | | | - Bo Feng
- DMPK, Vertex Pharmaceuticals, Boston, Massachusetts, 02210, USA
| | | | - Christopher Shaffer
- External Innovation, Research & Development, Biogen Inc., Cambridge, Massachusetts, USA
| | - Cory Kalvass
- DMPK-BA, AbbVie, Inc., North Chicago, Illinois, USA
| | - Dallas Bednarczyk
- Pharmacokinetic Sciences, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | | | | | - Edmund Hoppe
- DMPK, Boehringer-Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | | | - Holger Fischer
- Translational PK/PD and Clinical Pharmacology, Pharmaceutical Sciences, Roche Pharma Research & Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Li Di
- Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Groton, Connecticut, USA
| | | | - Scott Summerfield
- Bioanalysis Immunogenicity and Biomarkers, GSK, Gunnels Wood Road, Stevenage, SG1 2NY, Hertfordshire, UK
| | | | - Tristan S Maurer
- Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Cambridge, Massachusetts, USA
| | - Markus Fridén
- Department of Pharmacy, Uppsala University, Box 580, Uppsala, Sweden
- Inhalation Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Gothenburg, Sweden
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Grumetto L, Russo G. cΔlog k w IAM: can we afford estimation of small molecules' blood-brain barrier passage based upon in silico phospholipophilicity? ADMET AND DMPK 2022; 9:267-281. [PMID: 35300371 PMCID: PMC8920103 DOI: 10.5599/admet.1034] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 11/27/2021] [Indexed: 11/18/2022] Open
Abstract
56 compounds, whose log BB values were known from the scientific literature, were considered and their phospholipophilicity values were calculated in silico. These values, along with either experimentally determined or calculated lipophilicity values, were used to extract cΔ/Δ’log kwIAM parameters. cΔ/Δ’log kwIAM values were found inversely related to data of blood-brain barrier passage, especially in the < -0.20 log BB range and on the IAM.PC.DD2 phase (r2 = 0.79). In multiple linear regression, satisfactory statistic models (r2 (n-1) = 0.76), based on cΔ/Δ’log kwIAM.MG along with other in silico calculated descriptors, were achieved. This method brings the potential to be applied, along with other methodologies, to filter out solutes whose BBB permeation is foreseen to be substandard, thus allowing pharmaceutical companies/research institutes to focus on candidates that are more likely to concentrate in the brain.
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Affiliation(s)
- Lucia Grumetto
- Pharm-Analysis & Bio-Pharm Laboratory, Department of Pharmacy, School of Medicine and Surgery, University of Naples Federico II, Via D. Montesano, 49, I-80131, Naples, Italy
| | - Giacomo Russo
- School of Applied Sciences, Sighthill Campus, Edinburgh Napier University, 9 Sighthill Ct, EH11 4BN Edinburgh, United Kingdom
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Hansen SL, Dalsgaard PW, Linnet K, Rasmussen BS. Comparison of Comprehensive Screening Results in Postmortem Blood and Brain Tissue by UHPLC-QTOF-MS. J Anal Toxicol 2022; 46:1053-1058. [PMID: 35157763 PMCID: PMC9872219 DOI: 10.1093/jat/bkac011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 02/01/2022] [Accepted: 02/14/2022] [Indexed: 02/02/2023] Open
Abstract
Alternative specimens collected during autopsies can be valuable in postmortem toxicology in cases where peripheral blood is not available. The applicability of brain tissue as an alternative matrix for drug screening by ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry was investigated in this study. Results of the 50 most frequently detected drugs and metabolites of toxicological interest in blood and brain tissue samples from 1,719 autopsy cases were compared. Examination of the results in paired blood and brain tissue samples revealed that the two matrices were in general comparable, as the majority of the 50 analytes were observed in a high number of the examined cases in both blood and brain tissue. This demonstrates the potential of brain tissue as an alternative matrix for drug screening in postmortem toxicology or as a secondary matrix for confirmation.
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Affiliation(s)
| | - Petur Weihe Dalsgaard
- Department of Forensic Medicine, Section of Forensic Chemistry, Faculty of Health and Medical Sciences, University of Copenhagen, Frederik V’s Vej 11, DK-2100 Copenhagen Ø, Denmark
| | - Kristian Linnet
- Department of Forensic Medicine, Section of Forensic Chemistry, Faculty of Health and Medical Sciences, University of Copenhagen, Frederik V’s Vej 11, DK-2100 Copenhagen Ø, Denmark
| | - Brian Schou Rasmussen
- Department of Forensic Medicine, Section of Forensic Chemistry, Faculty of Health and Medical Sciences, University of Copenhagen, Frederik V’s Vej 11, DK-2100 Copenhagen Ø, Denmark
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5
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Summerfield SG, Yates JWT, Fairman DA. Free Drug Theory - No Longer Just a Hypothesis? Pharm Res 2022; 39:213-222. [PMID: 35112229 DOI: 10.1007/s11095-022-03172-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 01/19/2022] [Indexed: 12/14/2022]
Abstract
The Free Drug Hypothesis is a well-established concept within the scientific lexicon pervading many areas of Drug Discovery and Development, and yet it is poorly defined by virtue of many variations appearing in the literature. Clearly, unbound drug is in dynamic equilibrium with respect to absorption, distribution, metabolism, elimination, and indeed, interaction with the desired pharmacological target. Binding interactions be they specific (e.g. high affinity) or nonspecific (e.g. lower affinity/higher capacity) are governed by the same fundamental physicochemical tenets including Hill-Langmuir Isotherms, the Law of Mass Action and Drug Receptor Theory. With this in mind, it is time to recognise a more coherent version and consider it the Free Drug Theory and a hypothesis no longer. Today, we have the experimental and modelling capabilities, pharmacological knowledge, and an improved understanding of unbound drug distribution (e.g. Kpuu) to raise the bar on our understanding and analysis of experimental data. The burden of proof should be to rule out mechanistic possibilities and/or experimental error before jumping to the conclusion that any observations contradict these fundamentals.
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Affiliation(s)
- Scott G Summerfield
- UK Bioanalysis Immunogenicity and Biomarkers, GSK R&D, Stevenage, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, UK.
| | - James W T Yates
- Drug Metabolism and Pharmacokinetics, GSK R&D, Stevenage, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, UK
| | - David A Fairman
- Clinical Pharmacology Modelling and Simulation, GSK R&D, Stevenage, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, UK
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6
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Into the first biomimetic sphingomyelin stationary phase: Suitability in drugs’ biopharmaceutic profiling and block relevance analysis of selectivity. Eur J Pharm Sci 2021; 156:105585. [DOI: 10.1016/j.ejps.2020.105585] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/24/2020] [Accepted: 10/02/2020] [Indexed: 11/22/2022]
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7
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Badolo L, Thirstrup K, Nielsen SM, Püschl A, Jensen T, Watson S, Bundgaard C. Target-Mediated Brain Tissue Binding for Small Molecule Inhibitors of Heat Shock Protein 90. Pharmaceutics 2020; 12:pharmaceutics12111009. [PMID: 33105895 PMCID: PMC7690585 DOI: 10.3390/pharmaceutics12111009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/28/2020] [Accepted: 10/19/2020] [Indexed: 11/21/2022] Open
Abstract
Drug distribution in the brain is generally associated with an affinity for fatty brain tissues and therefore known to be species- and concentration-independent. We report here the effect of target affinity on brain tissue binding for 10 small molecules designed to inhibit brain heat shock protein 90 (HSP90), a widespread protein whose expression is 1–2% of total cytosolic proteins in eucaryotes. Our results show that increasing the test item concentrations from 0.3 to 100 µM increased the unbound fraction 32-fold for the most potent molecules, with no change for the inactive one (1.1 fold change). Saturation of HSP90 led to normal concentration-independent brain tissue binding. In vivo pharmacokinetics performed in rats showed that the overall volume of distribution of compounds is correlated with their affinity for HSP90. The in vitro binding and in vivo pharmacokinetics (PK) performed in rats showed that small molecule HSP90 inhibitors followed the principle of target-mediated drug disposition. We demonstrate that assessing unbound fractions in brain homogenate was subject to HSP90 target interference; this may challenge the process of linking systemic-free drug concentrations to central nervous system unbound concentrations necessary to establish the proper pharmacokinetics/pharmacodynamics (PK/PD) relation needed for human dose prediction.
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Affiliation(s)
- Lassina Badolo
- Translational DMPK, H. Lundbeck A/S, 2500 Copenhagen-Valby, Denmark;
- Correspondence:
| | | | - Søren Møller Nielsen
- Molecular Screening and Pharmacology, H. Lundbeck A/S, 2500 Copenhagen-Valby, Denmark;
| | - Ask Püschl
- Medicinal Chemistry, H. Lundbeck A/S, 2500 Copenhagen-Valby, Denmark; (A.P.); (T.J.); (S.W.)
| | - Thomas Jensen
- Medicinal Chemistry, H. Lundbeck A/S, 2500 Copenhagen-Valby, Denmark; (A.P.); (T.J.); (S.W.)
| | - Steve Watson
- Medicinal Chemistry, H. Lundbeck A/S, 2500 Copenhagen-Valby, Denmark; (A.P.); (T.J.); (S.W.)
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8
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Lovejoy DA, Hogg DW, Dodsworth TL, Jurado FR, Read CC, D'Aquila AL, Barsyte-Lovejoy D. Synthetic Peptides as Therapeutic Agents: Lessons Learned From Evolutionary Ancient Peptides and Their Transit Across Blood-Brain Barriers. Front Endocrinol (Lausanne) 2019; 10:730. [PMID: 31781029 PMCID: PMC6861216 DOI: 10.3389/fendo.2019.00730] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 10/10/2019] [Indexed: 11/18/2022] Open
Abstract
Peptides play a major role in the transmission of information to and from the central nervous system. However, because of their structural complexity, the development of pharmacological peptide-based therapeutics has been challenged by the lack of understanding of endogenous peptide evolution. The teneurin C-terminal associated peptides (TCAP) possess many of the required attributes of a practical peptide therapeutic. TCAPs, associated with the teneurin transmembrane proteins that bind to the latrophilins, members of the Adhesion family of G-protein-coupled receptors (GPCR). Together, this ligand-receptor unit plays an integral role in synaptogenesis, neurological development, and maintenance, and is present in most metazoans. TCAP has structural similarity to corticotropin-releasing factor (CRF), and related peptides, such as calcitonin and the secretin-based peptides and inhibits the (CRF)-associated stress response. Latrophilins are structurally related to the secretin family of GPCRs. TCAP is a soluble peptide that crosses the blood-brain barrier and regulates glucose transport into the brain. We posit that TCAP represents a phylogenetically older peptide system that evolved before the origin of the CRF-calcitonin-secretin clade of peptides and plays a fundamental role in the regulation of cell-to-cell energy homeostasis. Moreover, it may act as a phylogenetically older peptide system that evolved as a natural antagonist to the CRF-mediated stress response. Thus, TCAP's actions on the CNS may provide new insights into the development of peptide therapeutics for the treatment of CNS disorders.
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Affiliation(s)
- David A. Lovejoy
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
- Protagenic Therapeutics Inc., New York, NY, United States
| | - David W. Hogg
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Thomas L. Dodsworth
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Fernando R. Jurado
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Casey C. Read
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Andrea L. D'Aquila
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
- Department of Pediatrics, University of Alabama, Birmingham, AL, United States
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9
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Dhiman P, Malik N, Khatkar A. Lead optimization for promising monoamine oxidase inhibitor from eugenol for the treatment of neurological disorder: synthesis and in silico based study. BMC Chem 2019; 13:38. [PMID: 31384786 PMCID: PMC6661809 DOI: 10.1186/s13065-019-0552-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 03/08/2019] [Indexed: 01/30/2023] Open
Abstract
Natural based inhibitors of monoamine oxidase are promising drug candidates for the treatment of several neurodegenerative and neuropsychological disorders including depression, anxiety, Parkinson’s disease and Alzheimer’s disease. In the present study we designed and synthesized the eugenol based derivatives and investigated them for human MAO inhibitory potential as promising candidates for therapeutics of neurological disorders. Moreover, radical scavenging activity of designed derivatives was tested by and H2O2 and DPPH scavenging methods. Eugenol based derivatives were designed and synthesized for human MAO inhibitory action. The in silico and in vitro models were utilized for the evaluation of hMAO inhibition. The insight into molecular interactions among the compounds and both hMAO-A and hMAO-B active site was achieved by molecular docking studies. The two spectrophotometric titrations techniques were used to evaluate antioxidant potential. Compounds 5b and 16 were found as most active hMAO-A inhibitors with IC50 values of 5.989 ± 0.007 µM and 7.348 ± 0.027 µM respectively, through an appreciable selectivity index value of 0.19 and 0.14 respectively. In case of hMAO-B inhibition compounds 13a and 13b were found as most active hMAO-B inhibitors with IC50 values of 7.494 ± 0.014 µM and 9.183 ± 0.034 µM receptively and outstanding value of selectivity index of 5.14 and 5.72 respectively. Radical scavenging assay showed that compounds 5b, 5a, 9b, 9a were active antioxidants. The findings of present study indicated excellent correlation among dry lab and wet lab hMAO inhibitory experiments. Interestingly, the compounds exhibiting better MAO inhibition activity was also appeared as good antioxidant agents.
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Affiliation(s)
- Priyanka Dhiman
- Laboratory for Preservation Technology and Enzyme Inhibition Studies, Faculty of Pharmaceutical Sciences, M. D. University, Rohtak, Haryana 124001 India
| | - Neelam Malik
- Laboratory for Preservation Technology and Enzyme Inhibition Studies, Faculty of Pharmaceutical Sciences, M. D. University, Rohtak, Haryana 124001 India
| | - Anurag Khatkar
- Laboratory for Preservation Technology and Enzyme Inhibition Studies, Faculty of Pharmaceutical Sciences, M. D. University, Rohtak, Haryana 124001 India
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10
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Bhyrapuneni G, Thentu JB, Palacharla VRC, Muddana N, Aleti RR, Ajjala DR, Nirogi R. A definite measure of occupancy exposures, seeking with non-radiolabeled in vivo 5-HT2A receptor occupancy and in vitro free fractions. J Recept Signal Transduct Res 2018; 38:359-366. [PMID: 30481094 DOI: 10.1080/10799893.2018.1531888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Unbound drug concentration in the brain would be the true exposure responsible for specific target occupancy. Drug exposures from preclinical are total concentrations of those over/underestimate the clinical dose projection. With the application of mass spectrometry, the current work proposes a definite measure of test drug exposures at serotonin-2A occupancy. The 5-HT2A occupancy of antagonist in the rat brain has determined with non-radiolabeled tracer MDL-100,907 at an optimized dose (3 µg/kg) and treatment time (30 min). Equilibrium dialysis method determines the in vitro free fraction of the test antagonist in untreated rat brain homogenates and plasma. Drug-free fractions derived the unbound concentration (EC50) in plasma and brain at test doses. The corresponding binding affinities (Ki) correlated with the unbound concentrations. Except for quetiapine, the ED50 values in the dose-occupancy curves of antagonists are close and ranged from 1 to 3 mg/kg. The test drug quetiapine, eplivanserin, and clozapine showed high free fractions in plasma, but for ketanserin and olanzapine, the brain free fraction was higher. The correlation between the unbound EC50 of the antagonists and corresponding Ki values was good (r2=0.828). The improved EC50 accuracy with unbound concentrations was 10-250 folds in plasma and 10-170 folds in the brain. Further, the free fractions (fu, plasma/fu, brain) of test drugs had shown a correlation of ∼83% with brain permeability (Ctotal brain/Ctotal plasma), a limiting factor. Thus, correlating the occupancy with unbound exposure and pharmacology would result in an accurate measurement of drug potency and optimizes in selecting the clinical dose.
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11
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Summerfield SG, Zhang Y, Liu H. Examining the Uptake of Central Nervous System Drugs and Candidates across the Blood-Brain Barrier. ACTA ACUST UNITED AC 2016; 358:294-305. [DOI: 10.1124/jpet.116.232447] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 05/17/2016] [Indexed: 01/13/2023]
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12
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Mishra V, Kesharwani P. Dendrimer technologies for brain tumor. Drug Discov Today 2016; 21:766-78. [PMID: 26891979 DOI: 10.1016/j.drudis.2016.02.006] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 01/21/2016] [Accepted: 02/08/2016] [Indexed: 12/27/2022]
Abstract
Despite low prevalence, brain tumors are one of the most lethal forms of cancer. Unfortunately the blood-brain barrier (BBB), a highly regulated, well coordinated and efficient barrier, checks the permeation of most of the drugs across it. Hence, crossing this barrier is one of the most significant challenges in the development of efficient central nervous system therapeutics. Surface-engineered dendrimers improve biocompatibility, drug-release kinetics and aptitude to target the BBB and/or tumors and facilitate transportation of anticancer bioactives across the BBB. This review sheds light on different aspects of brain tumors and dendrimers based on different approaches for treatment including recent research, opportunities and challenges encountered in development of novel and efficient dendrimer-based therapeutics for the treatment of brain tumors.
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Affiliation(s)
- Vijay Mishra
- Pharmaceutical Nanotechnology Research Laboratory, Adina Institute of Pharmaceutical Sciences, Sagar, M.P. 470002, India
| | - Prashant Kesharwani
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA.
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13
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14
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Rankovic Z. CNS Drug Design: Balancing Physicochemical Properties for Optimal Brain Exposure. J Med Chem 2015; 58:2584-608. [DOI: 10.1021/jm501535r] [Citation(s) in RCA: 342] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Zoran Rankovic
- Eli Lilly and Company, 893 South
Delaware Street, Indianapolis, Indiana 46285, United States
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15
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Ball K, Bouzom F, Scherrmann JM, Walther B, Declèves X. Comparing translational population-PBPK modelling of brain microdialysis with bottom-up prediction of brain-to-plasma distribution in rat and human. Biopharm Drug Dispos 2014; 35:485-99. [PMID: 25044007 DOI: 10.1002/bdd.1908] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 06/13/2014] [Accepted: 07/02/2014] [Indexed: 12/25/2022]
Abstract
The prediction of brain extracellular fluid (ECF) concentrations in human is a potentially valuable asset during drug development as it can provide the pharmacokinetic input for pharmacokinetic-pharmacodynamic models. This study aimed to compare two translational modelling approaches that can be applied at the preclinical stage of development in order to simulate human brain ECF concentrations. A population-PBPK model of the central nervous system was developed based on brain microdialysis data, and the model parameters were translated to their corresponding human values to simulate ECF and brain tissue concentration profiles. In parallel, the PBPK modelling software Simcyp was used to simulate human brain tissue concentrations, via the bottom-up prediction of brain tissue distribution using two different sets of mechanistic tissue composition-based equations. The population-PBPK and bottom-up approaches gave similar predictions of total brain concentrations in both rat and human, while only the population-PBPK model was capable of accurately simulating the rat ECF concentrations. The choice of PBPK model must therefore depend on the purpose of the modelling exercise, the in vitro and in vivo data available and knowledge of the mechanisms governing the membrane permeability and distribution of the drug.
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Affiliation(s)
- Kathryn Ball
- Centre de Pharmacocinétique et Métabolisme, Groupe de Recherche Servier, Orléans, France
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16
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Salameh TS, Banks WA. Delivery of therapeutic peptides and proteins to the CNS. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2014; 71:277-99. [PMID: 25307220 PMCID: PMC6087545 DOI: 10.1016/bs.apha.2014.06.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Peptides and proteins have potent effects on the brain after their peripheral administration, suggesting that they may be good substrates for the development of CNS therapeutics. Major hurdles to such development include their relation to the blood-brain barrier (BBB) and poor pharmacokinetics. Some peptides cross the BBB by transendothelial diffusion and others cross in the blood-to-brain direction by saturable transporters. Some regulatory proteins are also transported across the BBB and antibodies can enter the CNS via the extracellular pathways. Glycoproteins and some antibody fragments can be taken up and cross the BBB by mechanisms related to adsorptive endocytosis/transcytosis. Many peptides and proteins are transported out of the CNS by saturable efflux systems and enzymatic activity in the blood, CNS, or BBB are substantial barriers to others. Both influx and efflux transporters are altered by various substances and in disease states. Strategies that manipulate these interactions between the BBB and peptides and proteins provide many opportunities for the development of therapeutics. Such strategies include increasing transendothelial diffusion of small peptides, upregulation of saturable influx transporters with allosteric regulators and other posttranslational means, use of vectors and other Trojan horse strategies, inhibition of efflux transporters including with antisense molecules, and improvement in pharmacokinetic parameters to overcome short half-lives, tissue sequestration, and enzymatic degradation.
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Affiliation(s)
- Therese S Salameh
- Geriatric Research Educational and Clinical Center, Veterans Affairs Puget Sound Health Care System, University of Washington, Seattle, Washington USA; Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, Washington, USA
| | - William A Banks
- Geriatric Research Educational and Clinical Center, Veterans Affairs Puget Sound Health Care System, University of Washington, Seattle, Washington USA; Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, Washington, USA.
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Cima MJ, Lee H, Daniel K, Tanenbaum LM, Mantzavinou A, Spencer KC, Ong Q, Sy JC, Santini J, Schoellhammer CM, Blankschtein D, Langer RS. Single compartment drug delivery. J Control Release 2014; 190:157-71. [PMID: 24798478 DOI: 10.1016/j.jconrel.2014.04.049] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 04/18/2014] [Accepted: 04/25/2014] [Indexed: 02/06/2023]
Abstract
Drug design is built on the concept that key molecular targets of disease are isolated in the diseased tissue. Systemic drug administration would be sufficient for targeting in such a case. It is, however, common for enzymes or receptors that are integral to disease to be structurally similar or identical to those that play important biological roles in normal tissues of the body. Additionally, systemic administration may not lead to local drug concentrations high enough to yield disease modification because of rapid systemic metabolism or lack of sufficient partitioning into the diseased tissue compartment. This review focuses on drug delivery methods that physically target drugs to individual compartments of the body. Compartments such as the bladder, peritoneum, brain, eye and skin are often sites of disease and can sometimes be viewed as "privileged," since they intrinsically hinder partitioning of systemically administered agents. These compartments have become the focus of a wide array of procedures and devices for direct administration of drugs. We discuss the rationale behind single compartment drug delivery for each of these compartments, and give an overview of examples at different development stages, from the lab bench to phase III clinical trials to clinical practice. We approach single compartment drug delivery from both a translational and a technological perspective.
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Affiliation(s)
- Michael J Cima
- The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Materials Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| | - Heejin Lee
- TARIS Biomedical, Inc., Lexington, MA 02421, USA
| | - Karen Daniel
- TARIS Biomedical, Inc., Lexington, MA 02421, USA
| | - Laura M Tanenbaum
- The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Aikaterini Mantzavinou
- The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Kevin C Spencer
- The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Materials Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Qunya Ong
- The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jay C Sy
- The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - John Santini
- On Demand Therapeutics, Inc., Menlo Park, CA 94025, USA
| | - Carl M Schoellhammer
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Daniel Blankschtein
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Robert S Langer
- The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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18
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Mechanistic Understanding of Brain Drug Disposition to Optimize the Selection of Potential Neurotherapeutics in Drug Discovery. Pharm Res 2014; 31:2203-19. [DOI: 10.1007/s11095-014-1319-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 01/28/2014] [Indexed: 01/09/2023]
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19
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Palmer AM, Alavijeh MS. Overview of experimental models of the blood-brain barrier in CNS drug discovery. ACTA ACUST UNITED AC 2013; 62:7.15.1-7.15.30. [PMID: 24510719 DOI: 10.1002/0471141755.ph0715s62] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The blood-brain barrier (BBB) is a physical and metabolic entity that isolates the brain from the systemic circulation. The barrier consists of tight junctions between endothelial cells that contain egress transporters and catabolic enzymes. To cross the BBB, a drug must possess the appropriate physicochemical properties to achieve a sufficient time-concentration profile in brain interstitial fluid (ISF). In this overview, we review techniques to measure BBB permeation, which is evidenced by the free concentration of compound in brain ISF over time. We consider a number of measurement techniques, including in vivo microdialysis and brain receptor occupancy following perfusion. Consideration is also given to the endothelial and nonendothelial cell systems used to assess both the BBB permeation of a test compound and its interactions with egress transporters, and computer models employed for predicting passive permeation and the probability of interactions with BBB transporters.
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Ball K, Bouzom F, Scherrmann JM, Walther B, Declèves X. Physiologically based pharmacokinetic modelling of drug penetration across the blood-brain barrier--towards a mechanistic IVIVE-based approach. AAPS JOURNAL 2013; 15:913-32. [PMID: 23784110 DOI: 10.1208/s12248-013-9496-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 05/09/2013] [Indexed: 01/09/2023]
Abstract
Predicting the penetration of drugs across the human blood-brain barrier (BBB) is a significant challenge during their development. A variety of in vitro systems representing the BBB have been described, but the optimal use of these data in terms of extrapolation to human unbound brain concentration profiles remains to be fully exploited. Physiologically based pharmacokinetic (PBPK) modelling of drug disposition in the central nervous system (CNS) currently consists of fitting preclinical in vivo data to compartmental models in order to estimate the permeability and efflux of drugs across the BBB. The increasingly popular approach of using in vitro-in vivo extrapolation (IVIVE) to generate PBPK model input parameters could provide a more mechanistic basis for the interspecies translation of preclinical models of the CNS. However, a major hurdle exists in verifying these predictions with observed data, since human brain concentrations can't be directly measured. Therefore a combination of IVIVE-based and empirical modelling approaches based on preclinical data are currently required. In this review, we summarise the existing PBPK models of the CNS in the literature, and we evaluate the current opportunities and limitations of potential IVIVE strategies for PBPK modelling of BBB penetration.
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Affiliation(s)
- Kathryn Ball
- Centre de Pharmacocinétique et Métabolisme, Groupe de Recherche Servier, Orléans, France
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21
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Di L, Kerns EH, Carter GT. Strategies to assess blood-brain barrier penetration. Expert Opin Drug Discov 2013; 3:677-87. [PMID: 23506148 DOI: 10.1517/17460441.3.6.677] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND The principles and screening strategies for brain penetration in drug discovery are important in identifying drug candidates with desirable CNS properties. OBJECTIVE Define key variables and assays that are essential for determining brain penetration. METHODS This review covers issues, methods, and strategies for assessing brain penetration of small molecules in drug discovery. RESULTS/CONCLUSION Brain penetration is assessed using both initial rate and extent at steady-state. Unbound drug is the active species that exerts pharmacological effects. Low brain penetration can be due to low blood-brain barrier (BBB) permeability, P-glycoprotein (Pgp) efflux, or high plasma protein binding. Successful methods include: parallel artificial membrane permeability assay (PAMPA)-BBB permeability, MDR1-MDCKII for Pgp efflux, B-P dialysis for fraction unbound, and in vivo B/P ratio to extrapolate unbound brain drug concentration.
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Affiliation(s)
- Li Di
- Principal Research Scientist II Wyeth Research, 865 Ridge Road, Monmouth Jct., Princeton, NJ 08852, USA +1 732 274 4489 ; +1 732 274 4505 ;
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22
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In vitro, in vivo and in silico models of drug distribution into the brain. J Pharmacokinet Pharmacodyn 2013; 40:301-14. [DOI: 10.1007/s10928-013-9303-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Accepted: 01/31/2013] [Indexed: 10/27/2022]
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Lanevskij K, Japertas P, Didziapetris R. Improving the prediction of drug disposition in the brain. Expert Opin Drug Metab Toxicol 2013; 9:473-86. [PMID: 23294027 DOI: 10.1517/17425255.2013.754423] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Ability to cross the blood-brain barrier is one of the key ADME characteristics of all drug candidates regardless of their target location in the body. While good brain penetration is essential for CNS drugs, it may lead to serious side effects in case of peripherally-targeted molecules. Despite a high demand of computational methods for estimating brain transport early in drug discovery, achieving good prediction accuracy still remains a challenging task. AREAS COVERED This article reviews various measures employed to quantify brain delivery and recent advances in QSAR approaches for predicting these properties from the compound's structure. Additionally, the authors discuss the classification models attempting to distinguish between permeable and impermeable chemicals. EXPERT OPINION Recent research in the field of brain penetration modeling showed an increasing understanding of the processes involved in drug disposition, although most models of brain/plasma partitioning still rely on purely statistical considerations. Preferably, new models should incorporate mechanistic knowledge since it is the prerequisite for guiding drug design efforts in the desired direction. To increase the efficiency of computational tools, a broader view is necessary, involving rate and extent of brain penetration, as well as plasma and brain tissue binding strength, instead of relying on any single property.
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Affiliation(s)
- Kiril Lanevskij
- VšĮ Aukštieji algoritmai, A. Mickeviciaus 29, LT-08117 Vilnius, Lithuania.
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24
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Deo AK, Theil FP, Nicolas JM. Confounding Parameters in Preclinical Assessment of Blood–Brain Barrier Permeation: An Overview With Emphasis on Species Differences and Effect of Disease States. Mol Pharm 2013; 10:1581-95. [DOI: 10.1021/mp300570z] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Anand K. Deo
- UCB Pharma S.A., Chemin du Foriest, B-1420 Braine-l’Alleud,
Belgium
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25
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The promiscuous binding of pharmaceutical drugs and their transporter-mediated uptake into cells: what we (need to) know and how we can do so. Drug Discov Today 2012. [PMID: 23207804 DOI: 10.1016/j.drudis.2012.11.008] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A recent paper in this journal sought to counter evidence for the role of transport proteins in effecting drug uptake into cells, and questions that transporters can recognize drug molecules in addition to their endogenous substrates. However, there is abundant evidence that both drugs and proteins are highly promiscuous. Most proteins bind to many drugs and most drugs bind to multiple proteins (on average more than six), including transporters (mutations in these can determine resistance); most drugs are known to recognise at least one transporter. In this response, we alert readers to the relevant evidence that exists or is required. This needs to be acquired in cells that contain the relevant proteins, and we highlight an experimental system for simultaneous genome-wide assessment of carrier-mediated uptake in a eukaryotic cell (yeast).
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26
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Comparison of brain capillary endothelial cell-based and epithelial (MDCK-MDR1, Caco-2, and VB-Caco-2) cell-based surrogate blood–brain barrier penetration models. Eur J Pharm Biopharm 2012; 82:340-51. [DOI: 10.1016/j.ejpb.2012.07.020] [Citation(s) in RCA: 149] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 05/14/2012] [Accepted: 07/31/2012] [Indexed: 12/18/2022]
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Abstract
The brain is one of the most protected organs in the body. There are two key barriers that control the access of endogenous substances and xenobiotics (drugs or toxins) to the CNS. These physiological structures are the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier. The BBB represents the main determinant of the effective delivery of drugs to the CNS. Good access through the BBB is essential if the target site is located within the CNS or, in contrast, can be a disadvantage if adverse reactions occur at central level. The development of new drugs targeted to the CNS requires a better knowledge of the factors affecting BBB permeation as well as in vitro and in silico predictive tools to optimize screening, and to reduce the attrition rate at later stages of drug development. This review discusses the particular characteristics of the biology and physiology of the BBB with respect to the permeation and distribution of drugs into the brain. The factors affecting rate, extent and distribution into the brain are discussed and a brief description of the in silico, in vitro, in situ and in vivo methods used to measure BBB transport are presented. Finally, the lastest proposals and strategies to enhance transport across the BBB of new CNS drugs are summarized.
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28
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Liu WY, Wang ZB, Zhang LC, Wei X, Li L. Tight junction in blood-brain barrier: an overview of structure, regulation, and regulator substances. CNS Neurosci Ther 2012; 18:609-15. [PMID: 22686334 DOI: 10.1111/j.1755-5949.2012.00340.x] [Citation(s) in RCA: 197] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Blood-brain barrier (BBB) is a dynamic interference that regulates the nutrition and toxic substance in and out of the central nervous system (CNS), and plays a crucial role in maintaining a stable circumstance of the CNS. Tight junctions among adjacent cells form the basic structure of BBB to limiting paracellular permeability. In the present review, the constituents of tight junction proteins are depicted in detail, together with the regulation of tight junction under stimulation and in pathological conditions. Tight junction modulators are also discussed.
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Affiliation(s)
- Wei-Ye Liu
- Department of Pharmacology, Second Military Medical University, Shanghai, China
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29
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Combining PET biodistribution and equilibrium dialysis assays to assess the free brain concentration and BBB transport of CNS drugs. J Cereb Blood Flow Metab 2012; 32:874-83. [PMID: 22274741 PMCID: PMC3345915 DOI: 10.1038/jcbfm.2012.1] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The passage of drugs in and out of the brain is controlled by the blood-brain barrier (BBB), typically, using either passive diffusion across a concentration gradient or active transport via a protein carrier. In-vitro and preclinical measurements of BBB penetration do not always accurately predict the in-vivo situation in humans. Thus, the ability to assay the concentration of novel drug candidates in the human brain in vivo provides valuable information for de-risking of candidate molecules early in drug development. Here, positron emission tomography (PET) measurements are combined with in-vitro equilibrium dialysis assays to enable assessment of transport and estimation of the free brain concentration in vivo. The PET and equilibrium dialysis data were obtained for 36 compounds in the pig. Predicted P-glycoprotein (P-gp) status of the compounds was consistent with the PET/equilibrium dialysis results. In particular, Loperamide, a well-known P-gp substrate, exhibited a significant concentration gradient consistent with active efflux and after inhibition of the P-gp process the gradient was removed. The ability to measure the free brain concentration and assess transport of novel compounds in the human brain with combined PET and equilibrium dialysis assays can be a useful tool in central nervous system (CNS) drug development.
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30
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Hitchcock SA. Structural Modifications that Alter the P-Glycoprotein Efflux Properties of Compounds. J Med Chem 2012; 55:4877-95. [DOI: 10.1021/jm201136z] [Citation(s) in RCA: 152] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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31
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Tavares AAS, Lewsey J, Dewar D, Pimlott SL. Radiotracer properties determined by high performance liquid chromatography: a potential tool for brain radiotracer discovery. Nucl Med Biol 2012; 39:127-35. [DOI: 10.1016/j.nucmedbio.2011.06.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 06/17/2011] [Accepted: 06/27/2011] [Indexed: 01/14/2023]
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Thompson MD, Beard DA. Physiologically based pharmacokinetic tissue compartment model selection in drug development and risk assessment. J Pharm Sci 2012; 101:424-35. [PMID: 21968734 PMCID: PMC3314064 DOI: 10.1002/jps.22768] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 08/31/2011] [Accepted: 09/02/2011] [Indexed: 01/24/2023]
Abstract
A well-stirred tank (WST) has been the predominant flow-limited tissue compartment model in physiologically based pharmacokinetic (PBPK) modeling. Recently, we developed a two-region asymptotically reduced (TAR) PBPK tissue compartment model through an asymptotic approximation to a two-region vascular-extravascular system to incorporate more biophysical detail than the WST model. To determine the relevance of a flow-limited TAR (F-TAR) approach, 75 structurally diverse drugs were evaluated herein using a priori predicted tissue:plasma partition coefficients along with hybrid and whole-body PBPK of eight rat tissues to determine the impact of model selection on simulation and optimization. Simulations showed that the F-TAR model significantly improved the ability to predict drug exposure, with hybrid and whole-body WST model error approaching 50% for tissues with larger vascular volumes. When optimization was used to fit F-TAR and WST models to pseudo data, WST-optimized drug partition coefficients more appropriately represented curve-fitting parameters rather than biophysically meaningful partition coefficients. Median F-TAR-optimized error ranged from -0.4% to +0.3%, whereas WST-optimized median error ranged from -22.2% to +1.8%. These studies demonstrated that the use of F-TAR represents a more accurate, biophysically realistic PBPK tissue model for predicting tissue exposure to drug and that it should be considered for use in drug development and regulatory review.
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Affiliation(s)
- Matthew D. Thompson
- Biotechnology and Bioengineering Center, Department of Physiology, Medical College of Wisconsin, Milwaukee, WI
| | - Daniel A. Beard
- Biotechnology and Bioengineering Center, Department of Physiology, Medical College of Wisconsin, Milwaukee, WI
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Ballini E, Virginio C, Medhurst SJ, Summerfield SG, Aldegheri L, Buson A, Carignani C, Chen YH, Giacometti A, Lago I, Powell AJ, Jarolimek W. Characterization of three diaminopyrimidines as potent and selective antagonists of P2X3 and P2X2/3 receptors with in vivo efficacy in a pain model. Br J Pharmacol 2011; 163:1315-25. [PMID: 21410458 DOI: 10.1111/j.1476-5381.2011.01322.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE P2X3 and P2X2/3 receptors are highly localized on the peripheral and central pathways of nociceptive signal transmission. The discovery of A-317491 allowed their validation as chronic inflammatory and neuropathic pain targets, but this molecule has a very limited oral bioavailability and CNS penetration. Recently, potent P2X3 and P2X2/3 blockers with a diaminopyrimidine core group and better bioavailability were synthesized and represent a new opportunity for the validation of P2X3-containing receptors as targets for pain. Here we present a characterization of three representative diaminopyrimidines. EXPERIMENTAL APPROACH The activity of compounds was evaluated in intracellular calcium flux and electrophysiological recordings from P2X receptors expressed in mammalian cells and in a in vivo model of inflammatory pain (complete Freund's adjuvant (CFA) in rat paws). KEY RESULTS Compound A potently blocked P2X3 (pIC(50)= 7.39) and P2X2/3 (pIC(50)=6.68) and showed no detectable activity at P2X1, P2X2, P2X4 and P2X7 receptors (pIC(50)< 4.7). Whole-cell voltage clamp electrophysiology confirmed these results. Compounds showed good selectivities when tested against a panel of different classes of target. In the CFA model, compound B showed significant anti-nociceptive effects (57% reversal at 3mg·kg(-1) ). CONCLUSIONS AND IMPLICATIONS The diaminopyrimidines were potent and selective P2X3 and P2X2/3 receptor antagonists, showing efficacy in vivo and represent useful tools to validate these receptors as targets for inflammatory and neuropathic pain and provide promising progress in the identification of therapeutic tools for the treatment of pain-related disorders.
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Affiliation(s)
- E Ballini
- GlaxoSmithKline, Molecular Discovery Research, Verona, Italy.
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Bundgaard C, Sveigaard C, Brennum LT, Stensbøl TB. Associating in vitro target binding and in vivo CNS occupancy of serotonin reuptake inhibitors in rats: the role of free drug concentrations. Xenobiotica 2011; 42:256-65. [PMID: 22017605 DOI: 10.3109/00498254.2011.618953] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The present study aimed at investigating the theory that free (unbound) active site concentrations are the best predictors of target binding of compounds blocking the serotonin transporter (Sert) in the central nervous system (CNS). Thirteen serotonin reuptake inhibitors were evaluated for their Sert-binding affinities in vitro and in vivo in rats together with their unbound fractions in plasma and brain. Cortical Sert occupancy was used in vivo to acquire EC₅₀-estimates from total plasma, free plasma, whole brain, and free brain concentrations after acute drug administration. The in vitro-in vivo Sert occupancy analyses showed that the best correlation was achieved when unbound brain concentrations were employed. Unbound brain concentrations also provided a better correlation when compared with unbound plasma concentrations, which could be related to lack of equilibrium between plasma and brain at time of measurements or involvement of active brain efflux processes. In addition, brain-free fractions were shown to be directly correlated to the lipophilicity of the compounds. These data emphasize the use and impact of applying free fraction data in assessment of pharmacological in vitro-in vivo correlations and demonstrates its use to validate in vivo Sert occupancy as pharmacodynamic marker for serotonin reuptake inhibitors in rats.
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Padowski JM, Pollack GM. The influence of distributional kinetics into a peripheral compartment on the pharmacokinetics of substrate partitioning between blood and brain tissue. J Pharmacokinet Pharmacodyn 2011; 38:743-67. [PMID: 21983688 DOI: 10.1007/s10928-011-9218-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 09/21/2011] [Indexed: 11/27/2022]
Abstract
Development of CNS-targeted agents often focuses on identifying compounds with "good" CNS exposure (brain-to-blood partitioning >1). Some compounds undergoing enterohepatic recycling (ER) evidence a partition coefficient, K (p,brain) (expressed as C (brain) /C (plasma)), that exceeds and then decreases to (i.e., overshoots) a plateau (distribution equilibrium) value, rather than increasing monotonically to this value. This study tested the hypothesis that overshoot in K (p,brain) is due to substrate residence in a peripheral compartment. Simulations were based on a 3-compartment model with distributional clearances between central and brain (CL (br)) and central and peripheral (CL (d)) compartments and irreversible clearance from the central compartment (CL). Parameters were varied to investigate the relationship between overshoot and peripheral compartment volume (V (p)), and how this relationship was modulated by other model parameters. Overshoot magnitude and duration were characterized as peak C (brain)/C (plasma) relative to the plateau value (%OS) and time to reach plateau (TRP). Except for systems with high CL (d), increasing V (p) increased TRP and %OS. Increasing brain (V (br)) or central (V (c)) distribution volumes eliminated V (p)-related OS. Parallel increases in all clearances shortened TRP, but did not alter %OS. Increasing either CL or CL (d) individually increased %OS related to V (p), while increasing CL (br) decreased %OS. Under realistic peripheral distribution scenarios, C (brain)/C (plasma) may overshoot substantially K (p,brain) at distribution equilibrium. This observation suggests potential for erroneous assessment of brain disposition, particularly for compounds which exhibit a large apparent V (p), and emphasizes the need for complete understanding of distributional kinetics when evaluating brain uptake.
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Affiliation(s)
- Jeannie M Padowski
- Curriculum in Toxicology, School of Medicine and Division of Pharmacotherapy and Experimental Therapeutics, School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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36
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Lanevskij K, Dapkunas J, Juska L, Japertas P, Didziapetris R. QSAR Analysis of Blood–Brain Distribution: The Influence of Plasma and Brain Tissue Binding. J Pharm Sci 2011; 100:2147-60. [DOI: 10.1002/jps.22442] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 11/11/2010] [Accepted: 11/16/2010] [Indexed: 11/07/2022]
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Lacombe O, Videau O, Chevillon D, Guyot AC, Contreras C, Blondel S, Nicolas L, Ghettas A, Bénech H, Thevenot E, Pruvost A, Bolze S, Krzaczkowski L, Prévost C, Mabondzo A. In vitro primary human and animal cell-based blood-brain barrier models as a screening tool in drug discovery. Mol Pharm 2011; 8:651-63. [PMID: 21438632 DOI: 10.1021/mp1004614] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Brain penetration is characterized by its extent and rate and is influenced by drug physicochemical properties, plasma exposure, plasma and brain protein binding and BBB permeability. This raises questions related to physiology, interspecies differences and in vitro/in vivo extrapolation. We herein discuss the use of in vitro human and animal BBB model as a tool to improve CNS compound selection. These cell-based BBB models are characterized by low paracellular permeation, well-developed tight junctions and functional efflux transporters. A study of twenty drugs shows similar compound ranking between rat and human models although with a 2-fold higher permeability in rat. cLogP < 5, PSA < 120 Å, MW < 450 were confirmed as essential for CNS drugs. An in vitro/in vivo correlation in rat (R² = 0.67; P = 2 × 10⁻⁴) was highlighted when in vitro permeability and efflux were considered together with plasma exposure and free fraction. The cell-based BBB model is suitable to optimize CNS-drug selection, to study interspecies differences and then to support human brain exposure prediction.
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Di L, Umland JP, Chang G, Huang Y, Lin Z, Scott DO, Troutman MD, Liston TE. Species Independence in Brain Tissue Binding Using Brain Homogenates. Drug Metab Dispos 2011; 39:1270-7. [DOI: 10.1124/dmd.111.038778] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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Mutlu NB, Değim Z, Yilmaz Ş, Eşsiz D, Nacar A. New perspective for the treatment of Alzheimer diseases: liposomal rivastigmine formulations. Drug Dev Ind Pharm 2011; 37:775-89. [PMID: 21231901 DOI: 10.3109/03639045.2010.541262] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The aim of this study was to determine the transportations of rivastigmine containing from various liposome formulations through Madin Darby Canine Kidney (MDCK) cells monolayer and to compare the in vitro test results with in vivo. There is no other liposome formulation of rivastigmine and the transportations of rivastigmine through MDCK cell monolayers or related study available in the literature. Cytotoxicity (MTT) test was used to determine cell viabilities. The effect of sodium-taurocholate or dimethyl-beta-cyclodextrine as penetration enhancer was also investigated. Characterization and stability studies for liposome formulations were performed. Permeation experiments of rivastigmine were performed through MDCK cells and dialysis membrane. The kinetic of release from liposomes was also investigated. The highest apparent permeability coefficient (log. values) was obtained with sodium-taurocholate liposomes for -1.15 ± 0.16 for MDCK cell. Rivastigmine liposomes and solutions were also administered to mice orally and intraperitonally. Acetylcholinesterase (AChE) activity was determined by Ellman method. AChE% inhibition values were calculated for both blood and brain after administration of rivastigmine solution and liposomes. The highest AChE inhibition was observed for rivastigmine-sodium-taurocholate liposomes. Histological observations of the mice' brains were performed under transmission electron microscope (TEM). The histological results were also indicated and supported all these findings.
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Affiliation(s)
- N Başaran Mutlu
- Department of Pharmaceutical Technology, Gazi University Faculty of Pharmacy, Ankara
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Smith DA, Di L, Kerns EH. The effect of plasma protein binding on in vivo efficacy: misconceptions in drug discovery. Nat Rev Drug Discov 2011; 9:929-39. [PMID: 21119731 DOI: 10.1038/nrd3287] [Citation(s) in RCA: 571] [Impact Index Per Article: 43.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Data from in vitro plasma protein binding experiments that determine the fraction of protein-bound drug are frequently used in drug discovery to guide structure design and to prioritize compounds for in vivo studies. However, we consider that these practices are usually misleading, because in vivo efficacy is determined by the free (unbound) drug concentration surrounding the therapeutic target, not by the free drug fraction. These practices yield no enhancement of the in vivo free drug concentration. So, decisions based on free drug fraction could result in the wrong compounds being advanced through drug discovery programmes. This Perspective provides guidance on the application of plasma protein binding information in drug discovery.
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Affiliation(s)
- Dennis A Smith
- Pharmacokinetics, Dynamics and Metabolism Department, Pfizer Global Research and Development, Ramsgate Road, Sandwich, Kent CT13 9UJ, UK
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Carl SM, Lindley DJ, Das D, Couraud PO, Weksler BB, Romero I, Mowery SA, Knipp GT. ABC and SLC transporter expression and proton oligopeptide transporter (POT) mediated permeation across the human blood--brain barrier cell line, hCMEC/D3 [corrected]. Mol Pharm 2010; 7:1057-68. [PMID: 20524699 DOI: 10.1021/mp900178j] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Initial studies indicate that the newly developed hCMEC/D3 cell line may prove to be a useful model for studying the physiology of the human blood-brain barrier (BBB) endothelium. The purpose of this study was to assess the mRNA expression of several ABC and SLC transporters, with an emphasis on the proton-coupled oligopeptide transporter superfamily (POT) transporters in this immortalized BBB cell model. The transport kinetics of POT-substrates was also evaluated. The hCMEC/D3 cell line was maintained in a modified EGM-2 medium in collagenated culture flasks and passaged every 3-4 days at approximately 85%-95% confluence. Messenger RNA (mRNA) expression of a variety of ABC and SLC transporters was evaluated using qRT-PCR arrays, while additional qRT-PCR primers were designed to assess the expression of POT members. The transport kinetics of mannitol and urea were utilized to quantitatively estimate the intercellular pore radius, while POT substrate transport was also determined to assess the suitability of the cell model from a drug screening perspective. Optimization of the cell line was attempted by culturing with on laminin and fibronectin enhanced collagen and in the presence of excess Ca(2+). hCMEC/D3 cells express both hPHT1 and hPHT2, while little to no expression of either hPepT1 or hPepT2 was observed. The relative expression of other ABC and SLC transporters is discussed. While POT substrate transport does suggest suitability for BBB drug permeation screening, the relative intercellular pore radius was estimated at 19 A, significantly larger than that approximated in vivo. Culturing with extracellular matrix proteins did not alter mannitol permeability. These studies characterized this relevant human hCMEC/D3 BBB cell line with respect to both the relative mRNA expression of various ABC and SLC transporters and its potential utility as an in vitro screening tool for brain permeation. Additional studies are required to adequately determine the potential to establish an in vivo correlation.
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Affiliation(s)
- Stephen M Carl
- Department of Industrial and Physical Pharmacy, School of Pharmacy, Purdue University, West Lafayette, Indiana, USA
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A new in situ brain perfusion flow correction method for lipophilic drugs based on the pH-dependent Crone-Renkin equation. Pharm Res 2010; 28:517-30. [PMID: 21042838 DOI: 10.1007/s11095-010-0298-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 09/28/2010] [Indexed: 09/29/2022]
Abstract
PURPOSE To determine the flow-corrected luminal permeability, P(c), of lipophilic drugs measured by the in situ brain perfusion method under circumstances where the traditional Crone-Renkin equation (CRE) method, using diazepam as a flow marker, often fails. METHODS The pH-dependent rate of brain penetration of five lipophilic drugs (amitriptyline, atomoxetine, imipramine, indomethacin, maprotiline, sertraline), as well as of atenolol and antipyrine, were measured in Sprague-Dawley rats. A new pH-dependent CRE was derived and applied to remove the hydrodynamic component of effective permeability, P(e), to produce P(c) values. RESULTS It was shown by the analysis of the in situ data in the pH 6.5-8.5 interval for the lipophilic bases that the average vascular flow F(pf) = 0.036 mL∙g(-1)∙s(-1), centered in a "flow-limit window" (FLW) bounded by P (e) (min) = 170 and P (e) (max) = 776 (10(-6) cm∙s(-1) units). It was shown that the traditional CRE is expected not to work for half of the molecules in the FLW and is expected to underestimate (up to 64-fold) the other half of the molecules. CONCLUSION The new pH-CRE flow correction method applied to lipophilic ionizable drugs, based on the pH partition hypothesis, can overcome the limitations of the traditional CRE.
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Physicochemical selectivity of the BBB microenvironment governing passive diffusion--matching with a porcine brain lipid extract artificial membrane permeability model. Pharm Res 2010; 28:337-63. [PMID: 20945153 DOI: 10.1007/s11095-010-0280-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 09/13/2010] [Indexed: 12/22/2022]
Abstract
PURPOSE To mimic the physicochemical selectivity of the blood-brain barrier (BBB) and to predict its passive permeability using a PAMPA model based on porcine brain lipid extract (PBLE 10%w/v in alkane). METHODS Three PAMPA (BD pre-coated and PBLE with 2 different lipid volumes) models were tested with 108 drugs. Abraham solvation descriptors were used to interpret the in vitro-in vivo correlation with 282 in situ brain perfusion measurements, spanning over 5 orders of magnitude. An in combo PAMPA model was developed from combining measured PAMPA permeability with one H-bond descriptor. RESULTS The in combo PAMPA predicted 93% of the variance of 197 largely efflux-inhibited in situ permeability training set. The model was cross-validated by the "leave-many-out" procedure, with q(2) = 0.92 ± 0.03. The PAMPA models indicated the presence of paramembrane water channels. Only the PBLE-based PAMPA-BBB model with sufficient lipid to fill all the internal pore space of the filter showed a wide dynamic range window, selectivity coefficient near 1, and was suitable for predicting BBB permeability. CONCLUSION BBB permeability can be predicted by in combo PAMPA. Its speed and substantially lower cost, compared to in vivo measurements, make it an attractive first-pass screening method for BBB passive permeability.
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Gynther M, Jalkanen A, Lehtonen M, Forsberg M, Laine K, Ropponen J, Leppänen J, Knuuti J, Rautio J. Brain uptake of ketoprofen–lysine prodrug in rats. Int J Pharm 2010; 399:121-8. [DOI: 10.1016/j.ijpharm.2010.08.019] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Revised: 08/04/2010] [Accepted: 08/13/2010] [Indexed: 01/15/2023]
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Zonzini L, Bianchi F, Cesari N, Sartori M. In vivo rat PK profiling in drug discovery: new challenges. Expert Opin Drug Discov 2010; 5:1031-7. [DOI: 10.1517/17460441.2010.509396] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Laura Zonzini
- GlaxoSmithKline SpA, Neurosciences Centre of Excellence for Drug Discovery, Medicine Research Centre, Verona, Italy
- Aptuit Srl, Medicine Research Centre, Via A. Fleming 4, 37135 Verona, Italy
| | - Federica Bianchi
- Aptuit Srl, Medicine Research Centre, Via A. Fleming 4, 37135 Verona, Italy
| | - Nicola Cesari
- Chiesi Farmaceutici SpA, Via Palermo, 26/A, 43100 Parma, Italy
| | - Matteo Sartori
- Aptuit Srl, Medicine Research Centre, Via A. Fleming 4, 37135 Verona, Italy
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Mensch J, L LJ, Sanderson W, Melis A, Mackie C, Verreck G, Brewster ME, Augustijns P. Application of PAMPA-models to predict BBB permeability including efflux ratio, plasma protein binding and physicochemical parameters. Int J Pharm 2010; 395:S0378-5173(10)00399-6. [PMID: 20685235 DOI: 10.1016/j.ijpharm.2010.05.037] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Revised: 05/20/2010] [Accepted: 05/21/2010] [Indexed: 10/19/2022]
Abstract
This study examines whether algorithms to predict brain penetration of 88 drug candidates could benefit from inclusion of PAMPA data such as P(eff), flux and membrane retention. Specifically the ability to fit experimentally derived LogBB data with PAMPA information and compound related physicochemical and structural parameters was assessed. Collected data were analyzed by partial least square analysis and various regression models for LogBB. Four PAMPA methodologies were evaluated in this study including: (1) a PAMPA-BLM (black lipid membrane) model, (2) a PAMPA-DS (double sink) model, (3) a PAMPA-BBB (blood-brain barrier) model and (4) a PAMPA-BBB-UWL (unstirred water layer). Additionally, plasma protein binding (PPB) experiments and a Caco-2 assay were performed to determine the unbound fraction in plasma and the efflux ratio, respectively, for subsets of the selected compounds. This information was combined with the obtained PAMPA data in an effort to improve the predictions of LogBB. Taken in aggregate, the results presented, suggest that the PAMPA-BLM parameters are the most important contributors to predict the LogBB. The optimized multiple linear regression (MLR) relationship including the PAMPA-BLM properties demonstrated a slightly improved prediction compared to the model without the PAMPA-BLM parameters. Including the plasma protein binding of 15 compounds resulted in a significantly improved PAMPA-BLM prediction of LogBB, while integrating the efflux ratio with PAMPA-BLM or PAMPA-BBB P(eff) values, resulted in improved classification of brain permeable [BBB+(LogBB>/=0)] and impermeable [BBB-(LogBB<0)] compounds.
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Affiliation(s)
- Jurgen Mensch
- ChemPharm Development, Johnson & Johnson Pharmaceutical Research & Development, a division of Janssen Pharmaceutica N.V., 2340 Beerse, Belgium
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Read KD, Braggio S. Assessing brain free fraction in early drug discovery. Expert Opin Drug Metab Toxicol 2010; 6:337-44. [PMID: 20102287 DOI: 10.1517/17425250903559873] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD The incorporation of brain tissue binding routinely in CNS drug discovery screening strategies has markedly changed the way CNS drug discovery is performed and is proving to be a valuable tool in identifying new therapies for CNS diseases. For many years emphasis has been placed on the magnitude of the brain to blood ratio, the bigger the better, even though, in many cases, brain total concentration (C(brain)) has no or, at best, poor correlation with receptor occupancy/pharmacodynamic readout. Today, C(brain) values measured during in vivo experiments are corrected for the fraction unbound measured through in vitro experiments using brain tissue homogenate or brain tissue slice to obtain an estimate of the brain unbound concentration (C(u,brain)), and this has been demonstrated across a range of CNS targets to give a much better correlation with receptor occupancy/pharmacodynamic readout. This apparently simple change in CNS lead optimisation strategy has de facto revolutionised the vision of the brain penetration concepts. AREAS COVERED IN THIS REVIEW This review will provide an overview of the use and applications of assessing brain free fraction to determine C(u,brain). TAKE HOME MESSAGE Assessing brain free fraction to determine C(u,brain) in CNS lead optimisation strategies is the surrogate of choice for rapidly assessing biophase concentration for the majority of CNS targets.
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Affiliation(s)
- Kevin D Read
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, Scotland, UK.
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Mensch J, Oyarzabal J, Mackie C, Augustijns P. In vivo, in vitro and in silico methods for small molecule transfer across the BBB. J Pharm Sci 2009; 98:4429-68. [DOI: 10.1002/jps.21745] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Lanevskij K, Japertas P, Didziapetris R, Petrauskas A. Ionization-Specific QSAR Models of BloodâBrain Penetration of Drugs. Chem Biodivers 2009; 6:2050-4. [DOI: 10.1002/cbdv.200900079] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Mehdipour AR, Hamidi M. Brain drug targeting: a computational approach for overcoming blood–brain barrier. Drug Discov Today 2009; 14:1030-6. [DOI: 10.1016/j.drudis.2009.07.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2008] [Revised: 06/29/2009] [Accepted: 07/20/2009] [Indexed: 01/04/2023]
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