Di / Kerns Drug-Like Properties

Concepts, Structure Design and Methods from ADME to Toxicity Optimization
2. Auflage 2015
ISBN: 978-0-12-801322-9
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 580 Seiten

Of the thousands of novel compounds that a drug discovery project team invents and that bind to the therapeutic target, only a fraction have sufficient ADME (absorption, distribution, metabolism, elimination) properties, and acceptable toxicology properties, to become a drug product that will successfully complete human Phase I clinical trials. Drug-Like Properties: Concepts, Structure Design and Methods from ADME to Toxicity Optimization, Second Edition, provides scientists and students the background and tools to understand, discover, and develop optimal clinical candidates. This valuable resource explores physiochemical properties, including solubility and permeability, before exploring how compounds are absorbed, distributed, and metabolized safely and stably. Review chapters provide context and underscore the importance of key concepts such as pharmacokinetics, toxicity, the blood-brain barrier, diagnosing drug limitations, prodrugs, and formulation. Building on those foundations, this thoroughly updated revision covers a wide variety of current methods for the screening (high throughput), diagnosis (medium throughput) and in-depth (low throughput) analysis of drug properties for process and product improvement. From conducting key assays for interpretation and structural analysis, the reader learns to implement modification methods and improve each ADME property. Through valuable case studies, structure-property relationship descriptions, and structure modification strategies, Drug-Like Properties, Second Edition, offers tools and methods for ADME/Tox scientists through all aspects of drug research, discovery, design, development, and optimization. - Provides a comprehensive and valuable working handbook for scientists and students in medicinal chemistry - Includes expanded coverage of pharmacokinetics fundamentals and effects - Contains updates throughout, including the authors' recent work in the importance of solubility in drug development; new and currently used property methods, with a reduction of seldom-used methods; and exploration of computational modeling methods

Li Di is an Associate Research Fellow at Pfizer, USA

Autoren/Hrsg.

Di, Li

Kerns, Edward H

Inhaltsverzeichnis

1;Front Cover;1
2;Drug-Like Properties: Concepts, Structure, Design, and Methods from ADME to Toxicity Optimization;4
3;Copyright;5
4;Dedication;6
5;Contents;8
6;Preface;20
6.1;Preface to Second Edition;20
6.2;Preface to First Edition;20
7;Chapter 1: Introduction;22
7.1;1.1. Drug-like Properties in Drug Discovery;22
7.2;1.2. Purpose of This Book;23
7.3;Problems;23
7.4;References;24
8;Chapter 2: Benefits of Property Assessment and Good Drug-Like Properties;26
8.1;2.1. Introduction;26
8.2;2.2. Discovery Scientists Optimize Many Properties;26
8.3;2.3. Introduction to the Drug Discovery and Development Process;27
8.4;2.4. Benefits of Good Drug-like Properties;29
8.4.1;2.4.1. Reduced Development Attrition;29
8.4.2;2.4.2. More Efficient Drug Discovery;29
8.4.3;2.4.3. More Efficient Drug Development;30
8.4.4;2.4.4. Higher Patient Compliance;30
8.4.5;2.4.5. Improved Biological Research in Drug Discovery;30
8.4.6;2.4.6. Enabled Partnerships for Drug Development;31
8.4.7;2.4.7. Human Modeling and Clinical Planning;31
8.4.8;2.4.8. Balance of Properties and Activity;31
8.5;2.5. Property Profiling in Drug Discovery;33
8.6;2.6. Drug-like Property Optimization in Drug Discovery;33
8.7;Problems;33
8.8;References;34
9;Chapter 3: In Vivo Environments Affect Drug Exposure;36
9.1;3.1. Introduction;36
9.2;3.2. Drug Dosing;37
9.3;3.3. Stomach;37
9.3.1;3.3.1. Gastric Acidic Degradation;38
9.4;3.4. Intestinal Environment;38
9.4.1;3.4.1. Dissolution Rate;40
9.4.2;3.4.2. Solubility;40
9.4.3;3.4.3. Permeability;40
9.4.4;3.4.4. Intestinal Metabolism;42
9.4.5;3.4.5. Intestinal Enzymatic Hydrolysis;42
9.4.6;3.4.6. Absorption Enhancement in the Intestine;43
9.5;3.5. Bloodstream;43
9.5.1;3.5.1. Plasma Enzyme Hydrolysis;44
9.5.2;3.5.2. Plasma Protein Binding;44
9.5.3;3.5.3. Red Blood Cell Binding;44
9.6;3.6. Liver;44
9.6.1;3.6.1. Permeation into and out of Hepatocytes;45
9.6.2;3.6.2. Hepatic Metabolism;45
9.6.3;3.6.3. Biliary Extraction;45
9.7;3.7. Kidney;45
9.8;3.8. Blood-Tissue Barriers;46
9.9;3.9. Tissue Distribution;47
9.9.1;3.9.1. Nonspecific Binding in Tissue;47
9.10;3.10. Consequences of Chirality;47
9.11;3.11. Overview of in vivo Challenges to Drug Exposure;48
9.12;Problems;48
9.13;References;49
10;Chapter 4: Prediction Rules for Rapid Property Profiling from Structure;50
10.1;4.1. Introduction;50
10.2;4.2. General Concepts for Prediction Rules;50
10.3;4.3. Rule of 5;51
10.4;4.4. Veber Rules;52
10.5;4.5. Waring Rules;53
10.6;4.6. Golden Triangle;53
10.7;4.7. Other Predictive Rules;54
10.8;4.8. Application of Rules for Compound Assessment;56
10.9;4.9. Applications of Predictive Rules;57
10.10;Problems;57
10.11;References;59
11;Chapter 5: Lipophilicity;60
11.1;5.1. Lipophilicity Fundamentals;60
11.2;5.2. Lipophilicity Effects;61
11.3;5.3. Lipophilicity Case Studies and Structure Modification;63
11.3.1;5.3.1. Lipophilicity Modification for Biological Activity;63
11.3.2;5.3.2. Lipophilicity Modification for Pharmacokinetics;64
11.3.3;5.3.3. Lipophilicity Modification for Toxicity;68
11.4;Problems;70
11.5;References;24
12;Chapter 6: pKa;72
12.1;6.1. pKa Fundamentals;72
12.2;6.2. pKa Effects;73
12.2.1;6.2.1. pKa Affects Efficacy;73
12.2.2;6.2.2. pKa Affects Pharmacokinetics;73
12.2.3;6.2.3. pKa Affects Toxicity;74
12.3;6.3. pKa Case Studies;74
12.3.1;6.3.1. pKa and Activity Examples;74
12.3.2;6.3.2. pKa and Pharmacokinetics Examples;75
12.4;6.4. Structure Modification Strategies for pKa;77
12.5;Problems;80
12.6;References;80
13;Chapter 7: Solubility;82
13.1;7.1. Introduction;82
13.2;7.2. Solubility Fundamentals;82
13.2.1;7.2.1. Solubility Varies with Compound Structure, Form, and Solution Conditions;82
13.2.2;7.2.2. Dissolution Rate;83
13.2.3;7.2.3. Structural Properties Affect Solubility;83
13.2.3.1;7.2.3.1. Lipophilicity and Crystal Intermolecular Forces Affect Solubility;83
13.2.3.2;7.2.3.2. Ionizability Greatly Affects Solubility;84
13.2.4;7.2.4. Kinetic and Thermodynamic Solubility;85
13.2.5;7.2.5. Consequences of Chirality on Solubility;87
13.3;7.3. Effects of Solubility;87
13.3.1;7.3.1. Low Solubility Affects In Vitro Assays;87
13.3.2;7.3.2. Low Solubility Limits Absorption and Causes Low Oral Bioavailability;87
13.3.3;7.3.3. Good Solubility is Essential for IV Formulation;89
13.3.4;7.3.4. How Much Solubility is Needed?;90
13.3.4.1;7.3.4.1. Maximum Absorbable Dose;90
13.3.4.2;7.3.4.2. Biopharmaceutics Classification System;92
13.3.5;7.3.5. Molecular Properties for Solubility and Permeability Are Often Opposed;94
13.4;7.4. Effects of Physiology on Solubility and Absorption;94
13.4.1;7.4.1. Physiology of the Gastrointestinal Tract;95
13.4.2;7.4.2. Species Differences in the GI Tract;95
13.4.3;7.4.3. Food Effect;96
13.5;7.5. Structure Modification Strategies to Improve Solubility;98
13.5.1;7.5.1. Add Ionizable Groups;99
13.5.2;7.5.2. Reduce log P;101
13.5.3;7.5.3. Add Hydrogen Bonding;102
13.5.4;7.5.4. Add Polar Group;103
13.5.5;7.5.5. Reduce MW;104
13.5.6;7.5.6. Out-of-Plane Substitution;104
13.5.7;7.5.7. Construct a Prodrug;106
13.6;7.6. Strategies to Improve Dissolution Rate;106
13.6.1;7.6.1. Reduce Particle Size;106
13.6.2;7.6.2. Prepare an Oral Solution;107
13.6.3;7.6.3. Formulate with Surfactants;107
13.6.4;7.6.4. Prepare a Salt Form;107
13.7;7.7. Salt Form;107
13.7.1;7.7.1. Solubility of Salts;108
13.7.2;7.7.2. Effect of Salt Form on Absorption and Oral Bioavailability;109
13.7.3;7.7.3. Salt Selection;110
13.7.4;7.7.4. Precautions of Using Salt Forms;111
13.8;7.8. Strategy for Solubility During Drug Discovery;111
13.9;Problems;112
13.10;References;113
14;Chapter 8: Permeability;116
14.1;8.1. Introduction;116
14.2;8.2. Permeability Fundamentals;116
14.2.1;8.2.1. Passive Transcellular Diffusion Permeability;117
14.2.2;8.2.2. Efflux Transport Permeability;120
14.2.3;8.2.3. Uptake Transport Permeability;121
14.2.4;8.2.4. Paracellular Permeability;121
14.2.5;8.2.5. Endocytosis Permeability;121
14.2.6;8.2.6. Net Permeability;121
14.3;8.3. Permeability Effects;122
14.3.1;8.3.1. Effect of Permeability on Absorption and Bioavailability;122
14.3.2;8.3.2. Effect of Permeability on Cell-Based Activity Assays;122
14.3.3;8.3.3. Permeation is Involved in Hepatic Clearance;123
14.3.4;8.3.4. Permeation is Involved in Renal Clearance;123
14.3.5;8.3.5. Permeation is Involved in Brain Efficacy;124
14.3.6;8.3.6. Permeation into Tissue Cells is Involved in Efficacy;124
14.4;8.4. Permeability Structure Modification Strategies;124
14.4.1;8.4.1. Replace Ionizable Group with Nonionizable Group;124
14.4.2;8.4.2. Add Lipophilicity;125
14.4.3;8.4.3. Isosteric Replacement of Polar Groups;125
14.4.4;8.4.4. Esterify Carboxylic Acid to Form Prodrug;127
14.4.5;8.4.5. Reduce Hydrogen Bonding and Polarity;127
14.4.6;8.4.6. Reduce Molecular Size;128
14.4.7;8.4.7. Add Nonpolar Side Chain;129
14.4.8;8.4.8. Prodrug;129
14.5;8.5. Strategy for Permeability;130
14.6;Problems;130
14.7;References;131
15;Chapter 9: Transporters;134
15.1;9.1. Introduction;134
15.2;9.2. Transporter Fundamentals;134
15.3;9.3. Transporter Effects;137
15.3.1;9.3.1. Transporters in Intestinal Epithelial Cells;140
15.3.2;9.3.2. Transporters in Liver Hepatocytes;140
15.3.3;9.3.3. Transporters in Kidney Epithelial Cells;140
15.3.4;9.3.4. Transporters in BBB Endothelial Cells;140
15.4;9.4. Efflux Transporters;140
15.4.1;9.4.1. P-glycoprotein (MDR1, ABCB1) [Efflux];141
15.4.1.1;9.4.1.1. Rules for P-gp Efflux Substrates;142
15.4.1.2;9.4.1.2. Case Study of P-gp Efflux;142
15.4.1.3;9.4.1.3. Structure Modification Strategies to Reduce P-gp Efflux;143
15.4.2;9.4.2. Breast Cancer Resistance Protein (BCRP, ABCG2) [Efflux];145
15.4.3;9.4.3. Multidrug Resistance Protein 2 (MRP2, ABCC2) [Efflux];146
15.4.4;9.4.4. Efflux Transporters in the BBB;148
15.5;9.5. Uptake Transporters;148
15.5.1;9.5.1. Organic Anion Transporting Polypeptide 1A2 for Brain Uptake;148
15.5.2;9.5.2. Organic Anion Transporting Polypeptide 1B1 and 1B3 for Liver Targeting and Clearance Prediction;148
15.5.3;9.5.3. Peptide Transporter 1 (PEPT1) for Intestine Absorption;150
15.5.4;9.5.4. Large Neutral Amino Acid Transporter (LAT1) for Brain Uptake;152
15.5.5;9.5.5. Monocarboxylate Transporter 1 (MCT1) for Oral Absorption;152
15.5.6;9.5.6. Organic Anion Transporters 1 and 3 for Renal Uptake;154
15.5.7;9.5.7. Organic Cation Transporter 2 (OCT2) for Renal Uptake;155
15.5.8;9.5.8. MATE1 and MATE2-K;156
15.5.9;9.5.9. Other Uptake Transporters;156
15.5.10;9.5.10. Structure Modification Strategies for Uptake Transporters;157
15.6;Problems;157
15.7;References;158
16;Chapter 10: Blood-Brain Barrier;162
16.1;10.1. Introduction;162
16.2;10.2. Fundamentals of Brain Exposure;162
16.2.1;10.2.1. Unbound Drug Brain Concentration, Cb,u, and AUCb,u;163
16.2.2;10.2.2. Unbound Brain-Blood Equilibrium Distribution, Kp,uu;163
16.2.3;10.2.3. BBB Permeation Affects Cb,u and Kp,uu;164
16.2.3.1;10.2.3.1. Rate and Extent of Brain Exposure;165
16.2.3.2;10.2.3.2. BBB Efflux Transport;166
16.2.3.3;10.2.3.3. Passive Transcellular Diffusion of BBB Affects Cb,u;166
16.2.3.4;10.2.3.4. Uptake Transport of BBB Affects Cb,u;166
16.2.3.5;10.2.3.5. No Fenestrations in BBB;167
16.2.3.6;10.2.3.6. No Paracellular or Pinocytosis Permeability of BBB;167
16.2.4;10.2.4. ADME Processes Affect Cb,u;167
16.2.5;10.2.5. BCSFB and CSF;167
16.2.5.1;10.2.5.1. Brain Exposure via BCSFB;167
16.2.5.2;10.2.5.2. Use of CSF as an ISF Surrogate;167
16.3;10.3. Effects of Brain Exposure on Efficacy and Drug Development;168
16.3.1;10.3.1. Effects of BBB Efflux on Human Efficacy;168
16.3.2;10.3.2. Effects of BBB Efflux on Human Clinical Development;168
16.3.3;10.3.3. Effects of Metabolic Clearance on Efficacy;168
16.3.4;10.3.4. Total Brain Exposure is Not Correlated to Efficacy;168
16.4;10.4. Structure-Passive Transcellular BBB Permeation Relationships;170
16.5;10.5. Structure Modification Strategies to Improve BBB Permeation;171
16.5.1;10.5.1. Reduce P-gp Efflux;172
16.5.2;10.5.2. Reduce Hydrogen Bonds;172
16.5.3;10.5.3. Increase Lipophilicity;172
16.5.4;10.5.4. Reduce Molecular Weight;173
16.5.5;10.5.5. Replace Carboxylic Acid Groups;173
16.5.6;10.5.6. Add an Intramolecular Hydrogen Bond;173
16.5.7;10.5.7. Modify or Select Structures for Affinity to BBB Uptake Transporters;174
16.6;10.6. Applications of Brain Exposure;174
16.6.1;10.6.1. Best Practices for Brain Exposure Assessment;174
16.6.2;10.6.2. Scheme for Assessing Brain Exposure;175
16.6.3;10.6.3. Projecting Human Brain Exposure;175
16.6.4;10.6.4. Selecting Candidates for CNS Drug Development;176
16.6.5;10.6.5. Minimizing Brain Exposure for Peripheral Drugs;176
16.7;Problems;178
16.8;References;179
17;Chapter 11: Metabolic Stability;182
17.1;11.1. Introduction;182
17.2;11.2. Metabolic Stability Fundamentals;183
17.2.1;11.2.1. Phase I Metabolism;184
17.2.2;11.2.2. Phase II Metabolism;188
17.3;11.3. Metabolic Stability Effects;190
17.4;11.4. Structure Modification Strategies for Phase I CYP Metabolic Stability;191
17.4.1;11.4.1. Block Metabolic Site by Adding Fluorine;192
17.4.2;11.4.2. Block Metabolic Site by Adding Other Blocking Groups;194
17.4.3;11.4.3. Remove Labile Functional Group;195
17.4.4;11.4.4. Cyclization;196
17.4.5;11.4.5. Change Ring Size;197
17.4.6;11.4.6. Change Chirality;197
17.4.7;11.4.7. Reduce Lipophilicity;197
17.4.8;11.4.8. Replace Unstable Groups;198
17.5;11.5. Structure Modification Strategies for Phase II Metabolic Stability;199
17.5.1;11.5.1. Introduce Electron-Withdrawing Groups and Steric Hindrance;199
17.5.2;11.5.2. Change Phenolic Hydroxyl to Cyclic Urea or Thiourea;200
17.5.3;11.5.3. Change Phenolic Hydroxyl to Prodrug;200
17.6;11.6. Applications of Metabolic Stability Data;201
17.7;11.7. Consequences of Chirality on Metabolic Stability;204
17.8;11.8. Substrate Specificity of CYP Isozymes;206
17.8.1;11.8.1. CYP1A2 Substrates;206
17.8.2;11.8.2. CYP2D6 Substrates;206
17.8.3;11.8.3. CYP2C9 Substrates;207
17.9;11.9. Aldehyde Oxidase;209
17.10;Problems;212
17.11;References;214
18;Chapter 12: Plasma Stability;216
18.1;12.1. Introduction;216
18.2;12.2. Plasma Stability Fundamentals;216
18.2.1;12.2.1. Consequences of Chirality on Plasma Stability;216
18.3;12.3. Effects of Plasma Instability;217
18.3.1;12.3.1. Pharmacokinetic Effects of Plasma Degradation;217
18.3.2;12.3.2. Degradation of Biological Drugs;217
18.3.3;12.3.3. Bioanalytical Effects of Plasma Degradation;217
18.3.4;12.3.4. Prodrugs and Antedrugs;217
18.4;12.4. Structure Modification Strategies to Improve Plasma Stability;219
18.4.1;12.4.1. Substitute an Amide for an Ester;219
18.4.2;12.4.2. Increase Steric Hindrance;220
18.4.3;12.4.3. Electron-Withdrawing Groups Decrease Plasma Stability for Antedrugs;221
18.4.4;12.4.4. Stabilize Biological Drug Candidates;221
18.5;12.5. Strategies for Plasma Stability;221
18.5.1;12.5.1. Diagnose Poor In Vivo Performance;221
18.5.2;12.5.2. Alert Teams to Plasma Hydrolysis Liability;222
18.5.3;12.5.3. Prioritize Compounds for in vivo Animal Studies;223
18.5.4;12.5.4. Prioritize Synthetic Efforts;224
18.5.5;12.5.5. Screening of Prodrugs;224
18.5.6;12.5.6. Guide Structural Modification;224
18.5.7;12.5.7. Verify the Plasma Storage Stability of Bioanalytical Samples;225
18.6;Problems;226
18.7;References;226
19;Chapter 13: Solution Stability;228
19.1;13.1. Introduction;228
19.2;13.2. Solution Stability Fundamentals;228
19.2.1;13.2.1. Degradation in Stock Solutions;228
19.2.2;13.2.2. Degradation During In Vitro Biological or ADME Assay;229
19.2.3;13.2.3. Degradation During In Vivo PK, Efficacy, and Toxicity Studies;229
19.2.4;13.2.4. Degradation Reactions;229
19.3;13.3. Effects of Solution Instability;230
19.4;13.4. Solution Stability Case Studies;230
19.4.1;13.4.1. pH Stability of a ?-Lactam;230
19.4.2;13.4.2. Selecting Conditions for Purification;230
19.4.3;13.4.3. Diagnose Poor In Vitro Bioassay Performance;231
19.4.4;13.4.4. Prioritize Compounds for In Vivo Animal Studies;232
19.4.5;13.4.5. Structure Elucidation of Degradation Products;232
19.5;13.5. Structure Modification Strategies to Improve Solution Stability;232
19.5.1;13.5.1. Eliminate or Modify the Unstable Group;232
19.5.2;13.5.2. Add an Electron-Withdrawing Group;234
19.5.3;13.5.3. Isosteric Replacement of Labile Functional Group;235
19.5.4;13.5.4. Increase Steric Hindrance;235
19.6;13.6. Applications of Solution Stability in Drug Discovery;236
19.6.1;13.6.1. Obtain an Early Alert About Stability Liabilities;236
19.6.2;13.6.2. Assist Selection of Conditions for Compound Purification Using Knowledge of Instability;236
19.6.3;13.6.3. Develop Structure-Stability Relationships;236
19.6.4;13.6.4. Diagnose Poor In Vitro Bioassay Performance;236
19.6.5;13.6.5. Diagnose Poor In Vivo Performance;236
19.6.6;13.6.6. Prioritize Compounds for In Vivo Animal Studies;236
19.6.7;13.6.7. Elucidate Structures of Degradation Products to Guide Synthetic Optimization;237
19.6.8;13.6.8. Perform Accelerated Stability Studies to Anticipate Development Liabilities;237
19.7;Problems;237
19.8;References;237
20;Chapter 14: Plasma and Tissue Binding;240
20.1;14.1. Introduction;240
20.2;14.2. Drug Binding in Plasma;240
20.3;14.3. Drug Binding in Tissue;243
20.4;14.4. Free Drug Hypothesis;243
20.5;Free Drug Hypothesis;243
20.6;14.5. Pharmacokinetics Principles of Oral Drugs Relevant to Drug Binding;245
20.7;14.6. The Useful Application of fu;245
20.8;14.7. Misconceptions and Unproductive Strategies for PPB;246
20.9;14.8. Best Practices Regarding PPB and Tissue Binding;248
20.10;Problems;248
20.11;References;249
21;Chapter 15: Cytochrome P450 Inhibition;250
21.1;15.1. Introduction;250
21.2;15.2. CYP Inhibition Fundamentals;250
21.2.1;15.2.1. Reversible CYP Inhibition;250
21.2.2;15.2.2. Irreversible CYP Inhibition (Mechanism-Based Inhibition);252
21.3;15.3. Effects of CYP Inhibition;254
21.3.1;15.3.1. Drug Candidate as a Perpetrator of Metabolic Inhibition DDI;254
21.3.2;15.3.2. Drug Candidate as Victim of Metabolic Inhibition;256
21.4;15.4. CYP Inhibition Case Studies;256
21.4.1;15.4.1. Consequences of Chirality on CYP Inhibition;257
21.5;15.5. Structure Modification Strategies to Reduce CYP Inhibition;257
21.6;15.6. Other DDIs;260
21.6.1;15.6.1. Drug Candidate as a Victim or Perpetrator of DDI Inhibition of a Non-CYP Metabolic Enzyme;260
21.6.2;15.6.2. Drug Candidate as a Victim or Perpetrator of DDI of a Transporter;260
21.6.3;15.6.3. Drug Candidate as a Victim or Perpetrator of Metabolic Enzyme Induction;260
21.6.4;15.6.4. DDI Caused by Foods and Dietary Supplements;260
21.7;15.7. Regulatory Guidance on DDI;260
21.8;15.8. Applications of CYP Inhibition;261
21.9;Problems;261
21.10;References;262
22;Chapter 16: hERG Blocking;264
22.1;16.1. Introduction;264
22.2;16.2. hERG Fundamentals;264
22.3;16.3. hERG Blocking Effects;266
22.4;16.4. hERG Blocking SAR;267
22.5;16.5. Structure Modification Strategies for hERG;268
22.6;16.6. Applications of hERG Blocking Assessment;270
22.7;Problems;270
22.8;References;270
23;Chapter 17: Toxicity;272
23.1;17.1. Introduction;272
23.2;17.2. Toxicity Fundamentals;272
23.3;17.3. Toxic Effect Categories;273
23.3.1;17.3.1. On-Target Effects;274
23.3.2;17.3.2. Off-Target Effects;274
23.3.3;17.3.3. Reactive Metabolites;274
23.4;17.4. Examples of Toxicity Effects;277
23.4.1;17.4.1. Metabolic Enzyme Induction;277
23.4.2;17.4.2. Genetic Toxicity and Carcinogenicity;277
23.4.3;17.4.3. Cytotoxicity;277
23.4.4;17.4.4. Teratogenicity;278
23.4.5;17.4.5. Biochemical Profile Changes;278
23.4.6;17.4.6. Phospholipidosis;278
23.5;17.5. In Vivo Toxicity;279
23.6;17.6. Case Studies of Toxicity in Drug Discovery;279
23.7;17.7. Rules for Off-Target Toxicity by Drug Discovery Compounds;280
23.8;17.8. Relationship of Cmax to in vivo Toxicity of Drug Discovery Compounds;280
23.9;17.9. Structure Modification Strategies to Improve Safety;280
23.10;Problems;282
23.11;References;282
24;Chapter 18: Integrity and Purity;284
24.1;18.1. Introduction;284
24.2;18.2. Fundamentals of Integrity and Purity;284
24.3;18.3. Integrity and Purity Effects;284
24.4;18.4. Applications of Integrity and Purity;285
24.4.1;18.4.1. Case Study;286
24.5;Problems;286
24.6;References;286
25;Chapter 19: Pharmacokinetics;288
25.1;19.1. Introduction;288
25.1.1;19.1.1. Reasons to Study PK;288
25.1.2;19.1.2. PK Parameters from Different Dosing Routes;288
25.2;19.2. PK Parameters;289
25.2.1;19.2.1. Volume of Distribution (Vd);289
25.2.2;19.2.2. Area under the Curve (AUC);291
25.2.3;19.2.3. Clearance (CL);292
25.2.4;19.2.4. Half-Life (t½);294
25.2.5;19.2.5. Bioavailability (F);295
25.3;19.3. Tissue Concentration;295
25.4;19.4. Using PK Data in Drug Discovery;295
25.5;19.5. Relationship of PK to PD;297
25.6;19.6. Applications of PK;297
25.7;Problems;301
25.8;References;302
26;Chapter 20: Lead Properties;304
26.1;20.1. Introduction;304
26.2;20.2. Lead-like Properties;304
26.3;20.3. Template Property Conservation;305
26.4;20.4. Including Properties in Hit Triage;305
26.5;20.5. Fragment-based Screening;306
26.6;20.6. Ligand LipophilicITY Efficiency;308
26.7;20.7. Conclusions;309
26.8;Problems;309
26.9;References;310
27;Chapter 21: Strategies for Integrating Drug-Like Properties into Drug Discovery;312
27.1;21.1. Introduction;312
27.2;21.2. Start Assessing Drug Properties Early to Prioritize Compounds and Plan Structure Modifications;312
27.3;21.3. Assess Drug Properties for all New Compounds Rapidly;313
27.4;21.4. Develop Structure-Property Relationships;313
27.5;21.5. Optimize Activity and Properties in Parallel;313
27.6;21.6. Use Single-property Assays to Guide Specific Modifications;313
27.7;21.7. Use Complex Property Methods for Decision-making and Human Modeling;314
27.8;21.8. Apply Property Data to Improve Biological Experiments;314
27.9;21.9. Use Customized Assays to Answer Specific Research Questions;314
27.10;21.10. Diagnose the Root Cause of Inadequate Pharmacokinetics;315
27.11;21.11. Run in vitro Assays Using Human Materials to Predict Human Performance;315
27.12;Problems;315
27.13;References;315
28;Chapter 22: Methods for Profiling Drug-Like Properties: General Concepts;316
28.1;22.1. Introduction;316
28.2;22.2. It is Valuable for Medicinal Chemists to Understand the ADMET Assays and Collaborate with ADMET Scientists;316
28.3;22.3. Choose an Ensemble of Key Properties to Evaluate;316
28.4;22.4. Use Relevant Assay Conditions;316
28.5;22.5. Property Data Should Be Readily Available;316
28.6;22.6. Evaluate the Cost-benefit Ratio for Assays;317
28.7;22.7. Use Well Developed Assays that Are Well Validated;317
28.8;Problems;318
28.9;References;318
29;Chapter 23: Lipophilicity Methods;320
29.1;23.1. In Silico Lipophilicity Methods;320
29.2;23.2. Lipophilicity Methods;322
29.2.1;23.2.1. Scaled-Down Shake Flask Method for Lipophilicity;322
29.2.2;23.2.2. Reversed Phase HPLC Method for Lipophilicity;323
29.2.3;23.2.3. CE Method for Lipophilicity;324
29.3;23.3. In-Depth Lipophilicity Methods;324
29.3.1;23.3.1. Shake Flask Method for Lipophilicity;324
29.3.2;23.3.2. pH-Metric Method for Lipophilicity;325
29.4;Problems;326
29.5;References;326
30;Chapter 24: pKa Methods;328
30.1;24.1. Introduction;328
30.2;24.2. In Silico pKa Methods;328
30.3;24.3. Laboratory pKa Methods;330
30.3.1;24.3.1. 96-Well Microtiter Plate UV Spectroscopy pKa Method;330
30.3.2;24.3.2. Spectral Gradient Analysis Method for pKa;331
30.3.3;24.3.3. Capillary Electrophoresis Method for pKa;332
30.3.4;24.3.4. Definitive pKa Method: pH-Metric;332
30.3.5;24.3.5. Potentiometric Titration Method for pKa;332
30.4;Problems;333
30.5;References;333
31;Chapter 25: Solubility Methods;334
31.1;25.1. Introduction;334
31.2;25.2. Solubility Calculation Estimation;334
31.3;25.3. Software for Solubility;334
31.4;25.4. Kinetic Solubility Methods;335
31.4.1;25.4.1. Direct UV Kinetic Solubility Method;337
31.4.2;25.4.2. Nephelometric Kinetic Solubility Method;338
31.4.3;25.4.3. Turbidimetric Kinetic Solubility Method;338
31.4.4;25.4.4. Pseudokinetic Solubility Method;339
31.5;25.5. Thermodynamic Solubility Methods;339
31.5.1;25.5.1. Equilibrium Shake Flask Thermodynamic Solubility Method;339
31.5.2;25.5.2. Potentiometric Thermodynamic Solubility Method;340
31.5.3;25.5.3. Thermodynamic Solubility in Various Solvents;340
31.6;25.6. Customized Solubility Methods;340
31.7;25.7. Dissolution Rate Measurement;342
31.8;25.8. DMSO Solubility;342
31.9;25.9. Commercial CRO Labs Offering Solubility Measurement;342
31.10;25.10. Strategy for Solubility Measurement;343
31.11;Problems;343
31.12;References;344
32;Chapter 26: Permeability Methods;346
32.1;26.1. Introduction;346
32.2;26.2. Computational Prediction of Permeability;346
32.2.1;26.2.1. Permeability Prediction Using Structural Property Rules;346
32.2.2;26.2.2. Permeability Prediction Using In Silico Methods;346
32.3;26.3. In Vitro Permeability Methods;347
32.3.1;26.3.1. Liposomal Permeability Method;347
32.3.2;26.3.2. IAM High-Performance Liquid Chromatography Permeability Method;347
32.3.3;26.3.3. Caco-2 Monolayer Permeability Method;348
32.3.3.1;26.3.3.1. General Protocol for Monolayer Permeability;349
32.3.3.2;26.3.3.2. Additional Considerations for Caco-2 Studies;350
32.3.4;26.3.4. MDCK Monolayer Permeability Method;352
32.3.4.1;26.3.4.1. MDCKII-LE Monolayer Permeability Method;352
32.3.5;26.3.5. Monolayer Permeability Method with Other Cell Lines;352
32.3.6;26.3.6. PAMPA—Parallel Artificial Membrane Permeability Assay;353
32.3.6.1;26.3.6.1. General Protocol for PAMPA Permeability;353
32.3.6.2;26.3.6.2. Additional Considerations for PAMPA Studies;353
32.3.7;26.3.7. Comparison of Caco-2 and PAMPA Methods;354
32.4;26.4. In-Depth Permeability Methods;355
32.4.1;26.4.1. Ussing Chamber;355
32.4.2;26.4.2. Cannulated In Vivo Hepatic Portal Vein;355
32.4.3;26.4.3. Perfusion In Vivo Methods;355
32.4.4;26.4.4. In Vivo Pharmacokinetics Method;355
32.5;26.5. Applications of Permeability in Drug Discovery;356
32.6;Problems;356
32.7;References;356
33;Chapter 27: Transporter Methods;360
33.1;27.1. Introduction;360
33.2;27.2. In Silico Transporter Methods;360
33.2.1;27.2.1. In Silico Methods for P-gp;360
33.2.2;27.2.2. In Silico Methods for BCRP;360
33.2.3;27.2.3. In Silico Methods for Other Transporters;360
33.3;27.3. In Vitro Transporter Methods;361
33.3.1;27.3.1. Bidirectional Cell Monolayer Transwell Permeability Methods for Transporter Studies;361
33.3.1.1;27.3.1.1. Caco-2 Permeability Method for Transporters;362
33.3.1.2;27.3.1.2. Transfected Cell Line Permeability Method for Transporters;362
33.3.2;27.3.2. Plated Cell Monolayer Uptake Method for Transporters;364
33.3.3;27.3.3. Cell Suspension Oil Spin Method for Transporters;364
33.3.4;27.3.4. Sandwich-Cultured Hepatocyte Method for Transporters;365
33.3.5;27.3.5. Media Loss Method for Transporters;365
33.3.6;27.3.6. Oocyte Uptake Method for Transporters;366
33.3.7;27.3.7. Inverted Vesicle Assay for Transporters;366
33.3.8;27.3.8. ATPase Assay for ABC Transporters;367
33.3.9;27.3.9. Calcein AM Assay for P-gp Inhibitor;368
33.4;27.4. In Vivo Methods for Transporters;369
33.4.1;27.4.1. Genetic Knockout Animal Experiments for Transporters;369
33.4.2;27.4.2. Chemical Knockout Experiments for Transporters;369
33.5;Problems;369
33.6;References;369
34;Chapter 28: Blood-Brain Barrier Methods;372
34.1;28.1. Introduction;372
34.2;28.2. Methods for BBB Permeability;372
34.2.1;28.2.1. Computational and In Silico Methods for BBB Permeability;373
34.2.1.1;28.2.1.1. Computational Methods for BBB Permeability and Brain Exposure;373
34.2.1.2;28.2.1.2. In Silico Classification Methods;373
34.2.1.3;28.2.1.3. QSAR BBB Permeability Methods;373
34.2.1.4;28.2.1.4. Commercial BBB Permeability Software;373
34.2.2;28.2.2. In Vitro Methods for BBB Permeability;374
34.2.2.1;28.2.2.1. In Vitro Physicochemical Methods for BBB Permeability;374
34.2.2.2;28.2.2.2. In Vitro PAMPA-BBB Method for BBB Permeability;375
34.2.2.3;28.2.2.3. In Vitro DeltalogP Method for BBB Permeability;376
34.2.2.4;28.2.2.4. In Vitro IAM HPLC Method for BBB Permeability;376
34.2.2.5;28.2.2.5. In Vitro Surface Activity Method for BBB Permeability;376
34.2.2.6;28.2.2.6. In Vitro Cell Monolayer Methods for BBB Permeability;377
34.2.2.6.1;28.2.2.6.1. In Vitro Microvessel Endothelial Cell Permeability Method for BBB Permeability;377
34.2.2.6.2;28.2.2.6.2. In Vitro Caco-2 Method for BBB Permeability;378
34.2.2.6.3;28.2.2.6.3. In Vitro MDR1-MDCKII Method for BBB Permeability;378
34.2.2.6.4;28.2.2.6.4. In Vitro TR-BBB and TM-BBB Cell Lines for BBB Permeability;378
34.2.3;28.2.3. In Vivo Methods for BBB Permeability;379
34.2.3.1;28.2.3.1. In Situ Brain Perfusion Method for BBB Permeability;379
34.2.3.2;28.2.3.2. In Vivo Brain Uptake Index Method for BBB Permeability;380
34.2.3.3;28.2.3.3. In Vivo Mouse Brain Uptake Method for BBB Permeability and Brain Distribution;380
34.3;28.3. Methods for Brain Binding and Distribution;382
34.3.1;28.3.1. In Silico Methods for Brain Binding;382
34.3.2;28.3.2. In Vitro Methods for Brain Binding;382
34.3.2.1;28.3.2.1. In Vitro Equilibrium Dialysis for Brain Binding;382
34.3.2.2;28.3.2.2. In Vitro Brain Slice Uptake Method for Brain Binding;383
34.3.2.3;28.3.2.3. In Vitro Lipid-coated Bead Method for Brain Binding;383
34.3.2.4;28.3.2.4. In Vitro Ultracentrifugation Brain Homogenate Method for Brain Binding;383
34.3.2.5;28.3.2.5. In Vitro Microemulsion Retention Factor Method for Brain Binding;383
34.3.3;28.3.3. In Vivo Measurement of Brain Distribution;384
34.3.3.1;28.3.3.1. In Vivo General Methodology for NeuroPK Studies;384
34.3.3.1.1;28.3.3.1.1. Effect of Residual Blood in Brain PK Studies;385
34.3.3.2;28.3.3.2. In Vivo NeuroPK with Transporter KO Mice;385
34.3.3.3;28.3.3.3. In Vivo NeuroPK for Cerebrospinal Fluid;385
34.3.3.4;28.3.3.4. In Vivo Microdialysis Method for Brain Distribution;386
34.3.3.5;28.3.3.5. In Vivo Imaging for Brain Distribution;386
34.4;28.4. Applications of BBB Permeation and Brain Distribution Methods;386
34.5;Problems;387
34.6;References;387
35;Chapter 29: Metabolic Stability Methods;392
35.1;29.1. Introduction;392
35.2;29.2. Metabolic Stability Methods;392
35.3;29.3. In Silico Metabolic Stability Methods;393
35.4;29.4. In Vitro Metabolic Stability Methods;393
35.4.1;29.4.1. General Aspects of Metabolic Stability Methods;393
35.4.1.1;29.4.1.1. Metabolic Stability Materials;393
35.4.1.2;29.4.1.2. Detection Methods for Metabolic Stability;396
35.4.2;29.4.2. In Vitro Microsomal Assay for Metabolic Stability;396
35.4.3;29.4.3. In Vitro S9 Assay for Metabolic Stability;401
35.4.4;29.4.4. In Vitro Hepatocytes Assay for Metabolic Stability;401
35.4.5;29.4.5. In Vitro Phase II Assay for Metabolic Stability;401
35.4.6;29.4.6. Metabolic Reaction Phenotyping;402
35.4.7;29.4.7. In Vitro Metabolite Structure Identification;403
35.5;Problems;406
35.6;References;406
36;Chapter 30: Plasma Stability Methods;408
36.1;30.1. Introduction;408
36.2;30.2. General Protocol for in vitro Plasma Stability;408
36.3;30.3. Low-throughput Method for in vitro Plasma Stability;409
36.4;30.4. High-throughput Method for in vitro Plasma Stability;409
36.5;30.5. Structure Elucidation of Plasma Degradation Products;412
36.6;30.6. Strategies for Plasma Stability Measurement;412
36.7;Problems;413
36.8;References;24
37;Chapter 31: Solution Stability Methods;414
37.1;31.1. Introduction;414
37.2;31.2. Methodology for Solution Stability Measurement;414
37.2.1;31.2.1. General Considerations for Drug Discovery Solution Stability Assessment;414
37.2.2;31.2.2. Quenching Problem in Solution Stability Assays;414
37.2.3;31.2.3. An Efficient and Effective Assay Design for Solution Stability;415
37.3;31.3. Method for Solution Stability in Biological Assay Media;416
37.4;31.4. Example Methods from the Literature for pH Solution Stability;416
37.5;31.5. Methods for Solution Stability in Simulated GI Fluids;417
37.6;31.6. Identification of Degradation Products from Solution Stability Assays;418
37.7;31.7. In-depth Solution Stability Assessment in Late Stage Drug Discovery;418
37.8;31.8. Strategy for Solution Stability Assessment;420
37.9;Problems;420
37.10;References;420
38;Chapter 32: CYP Inhibition Methods;422
38.1;32.1. Introduction;422
38.2;32.2. In Silico CYP Inhibition Methods;422
38.3;32.3. In Vitro Reversible CYP Inhibition Methods;422
38.3.1;32.3.1. CYP Enzyme Material for CYP Inhibition Methods;423
38.3.2;32.3.2. Probe Substrate Compounds for CYP Inhibition Methods;423
38.3.3;32.3.3. Measurement Techniques for CYP Inhibition Methods;425
38.3.4;32.3.4. Assay Protocols for Reversible CYP Inhibition Methods;425
38.3.4.1;32.3.4.1. Fluorescent Protocol for Reversible CYP Inhibition;426
38.3.4.2;32.3.4.2. Single Drug Probe Substrate HLM Protocol for Reversible CYP Inhibition;426
38.3.4.3;32.3.4.3. Cocktail Drug Probe Substrate HLM Protocol for Reversible CYP Inhibition;427
38.3.4.4;32.3.4.4. Double Cocktail Assay for Reversible CYP Inhibition;427
38.4;32.4. In Vitro Irreversible (TDI) CYP Inhibition Methods;429
38.4.1;32.4.1. Abbreviated TDI Irreversible CYP Inhibition Protocol;429
38.4.2;32.4.2. IC50 Shift TDI CYP Inhibition Protocol;430
38.4.3;32.4.3. In-Depth TDI CYP Inhibition Methods;430
38.5;32.5. CYP Inhibition Method Applications;432
38.6;Problems;433
38.7;References;433
39;Chapter 33: Plasma and Tissue Binding Methods;436
39.1;33.1. Introduction;436
39.2;33.2. In Silico Plasma Protein Binding Methods;436
39.2.1;33.2.1. Literature Computational Plasma Protein Binding Methods;436
39.2.2;33.2.2. Commercial In Silico Plasma Protein Binding Methods;436
39.3;33.3. In Vitro Binding Methods;437
39.3.1;33.3.1. Equilibrium Dialysis;437
39.3.1.1;33.3.1.1. Equilibrium Dialysis Method for Plasma;437
39.3.1.2;33.3.1.2. Equilibrium Dialysis Method for Tissue;438
39.3.1.3;33.3.1.3. Equilibrium Dialysis Method for Microsomes and Hepatocytes;438
39.3.2;33.3.2. Ultrafiltration Method;438
39.3.3;33.3.3. Ultracentrifugation Method;439
39.3.4;33.3.4. Immobilized Protein HPLC Column Method;439
39.3.5;33.3.5. Microdialysis Method;439
39.3.6;33.3.6. Other Plasma Protein Binding Methods;440
39.4;33.4. Red Blood Cell Binding;440
39.5;33.5. Contract Research Laboratories for Protein Binding Assays;441
39.6;Problems;441
39.7;References;441
40;Chapter 34: hERG Methods;444
40.1;34.1. Introduction;444
40.2;34.2. In Silico hERG Methods;444
40.3;34.3. In Vitro hERG Methods;446
40.3.1;34.3.1. In Vitro Fluorescent Membrane Potential Sensitive Dye Method for hERG;446
40.3.2;34.3.2. In Vitro Radioactive Ligand Binding Method for hERG;447
40.3.3;34.3.3. In Vitro Fluorescence Polarization Ligand Binding Method for hERG;448
40.3.4;34.3.4. In Vitro Rubidium Flux Method for hERG;448
40.3.5;34.3.5. In Vitro Manual Patch-Clamp Method for hERG;448
40.3.6;34.3.6. In Vitro Automated Patch-Clamp Method for hERG;449
40.3.7;34.3.7. In Vitro iPSC Cardiomyocyte Method for hERG;450
40.4;34.4. Ex Vivo Methods for hERG Blocking;451
40.4.1;34.4.1. Purkinje Fiber Ex Vivo Method for hERG Blocking;451
40.4.2;34.4.2. Langendorff Perfused Isolated Heart Ex Vivo Method for hERG Blocking;451
40.5;34.5. In Vivo Electrocardiography Telemetry for hERG Blocking;451
40.6;34.6. Applications of hERG Blocking Methods in Drug Discovery;451
40.7;Problems;451
40.8;References;452
41;Chapter 35: Toxicity Methods;454
41.1;35.1. Introduction;454
41.2;35.2. In Silico Toxicity Methods;454
41.2.1;35.2.1. Knowledge-Based Expert System In Silico Methods for Toxicity;455
41.2.2;35.2.2. Statistics-Based In Silico Methods for Toxicity;455
41.3;35.3. In Vitro Toxicity Methods;455
41.3.1;35.3.1. Drug-Drug Interaction Methods;455
41.3.1.1;35.3.1.1. Metabolic Enzyme Induction Methods;456
41.3.1.1.1;35.3.1.1.1. Hepatocyte Method for Metabolic Enzyme Induction;457
41.3.1.1.1.1;35.3.1.1.1.1. In Vitro Measurement of mRNA for Metabolic Enzyme Induction;457
41.3.1.1.1.2;35.3.1.1.1.2. In Vitro Measurement of Enzyme Activity for CYP Induction;457
41.3.1.1.2;35.3.1.1.2. In Vitro Nuclear Receptor Activation Methods for CYP Induction;457
41.3.2;35.3.2. In Vitro hERG Blocking Methods;458
41.3.3;35.3.3. In Vitro Genetic Toxicity Methods;458
41.3.3.1;35.3.3.1. In Vitro Ames Mutagenicity Method;458
41.3.3.2;35.3.3.2. In Vitro TK Mouse Lymphoma Cell Mutagenicity Method;459
41.3.3.3;35.3.3.3. In Vitro HPRT Chinese Hamster Ovary Cell Mutagenicity Method;459
41.3.3.4;35.3.3.4. In Vitro Micronucleus Clastogenicity Method;459
41.3.3.5;35.3.3.5. In Vitro Comet Clastogenicity Method;459
41.3.3.6;35.3.3.6. In Vitro GADD45a-GFP Mutagenicity and Clastogenicity Method;460
41.3.4;35.3.4. In Vitro Cytotoxicity Methods;460
41.3.4.1;35.3.4.1. In Vitro ATP Depletion Cytotoxicity Method;460
41.3.4.2;35.3.4.2. In Vitro MTT Human Hepatocyte Cytotoxicity Method;460
41.3.4.3;35.3.4.3. In Vitro LDH Cytotoxicity Method;460
41.3.4.4;35.3.4.4. In Vitro Neutral Red Cytotoxicity Method;461
41.3.5;35.3.5. In Vitro Embryo Teratogenicity Methods;461
41.3.6;35.3.6. In Vitro Off-Target Selectivity Screens;461
41.3.7;35.3.7. In Vitro Reactive Metabolite Methods;461
41.3.7.1;35.3.7.1. In Vitro Reactive Metabolite Method Using Glutathione Trapping;461
41.3.7.2;35.3.7.2. In Vitro Reactive Metabolite Method Using Covalent Protein Binding;461
41.4;35.4. In Vivo Toxicity Methods;462
41.4.1;35.4.1. Short-Term In Vivo Toxicity Methods;462
41.4.2;35.4.2. Preclinical and Clinical In Vivo Toxicity Methods;462
41.4.3;35.4.3. In Vivo Toxic Biomarker Methods;463
41.4.3.1;35.4.3.1. In Vivo Toxicometabonomic Method;463
41.4.3.2;35.4.3.2. In Vivo Toxicoproteomic Method;464
41.4.3.3;35.4.3.3. In Vivo Toxicogenomic Method;464
41.5;Problems;464
41.6;References;464
42;Chapter 36: Integrity and Purity Methods;468
42.1;36.1. Introduction;468
42.2;36.2. Samples for Integrity and Purity Profiling;469
42.3;36.3. Requirements of Integrity and Purity Profiling Methods;469
42.4;36.4. Integrity and Purity Method Characteristics;469
42.4.1;36.4.1. Sample Preparation;470
42.4.2;36.4.2. Sample Component Separation;471
42.4.3;36.4.3. Quantitation;471
42.4.4;36.4.4. Identity Characterization;472
42.5;36.5. Follow Up on Negative Identity Results;472
42.6;36.6. Example Generic High-Throughput Purity and Integrity Method;473
42.7;36.7. Purity and Integrity Case Studies;473
42.8;Problems;475
42.9;References;475
43;Chapter 37: Pharmacokinetic Methods;476
43.1;37.1. Introduction;476
43.2;37.2. Dosing for PK Studies;476
43.2.1;37.2.1. Single Compound Dosing;476
43.2.2;37.2.2. Cassette Dosing;476
43.3;37.3. PK Sampling and Sample Preparation;477
43.4;37.4. LC/MS/MS Analysis;478
43.5;37.5. Advanced PK Studies;479
43.6;37.6. Example Pharmacokinetic Data;479
43.7;37.7. Tissue Penetration;479
43.8;37.8. Unbound Drug Concentration in Plasma or Tissue;481
43.9;37.9. Contract Research Laboratories;481
43.10;Problems;481
43.11;References;482
44;Chapter 38: Diagnosing and Improving Pharmacokinetic Performance;484
44.1;38.1. Introduction;484
44.2;38.2. Diagnosing Underlying Property Limitations from PK Performance;485
44.2.1;38.2.1. Diagnosing the Cause of High Clearance or Short Half-Life;485
44.2.2;38.2.2. Diagnosing Cause of Low Oral Bioavailability;485
44.2.3;38.2.3. Diagnosing the Cause of Low AUC or Cmax;486
44.2.4;38.2.4. Diagnosing the Cause of Nonlinear Pharmacokinetics;486
44.3;38.3. Case Studies on Diagnosing Unfavorable PK Behavior;486
44.3.1;38.3.1. Pharmacokinetics of CCR5 antagonist UK-427,857;486
44.3.2;38.3.2. Pharmacokinetics of Triazole Antifungal Voriconazole;487
44.3.3;38.3.3. Optimization of a PDE5 Inhibitor;489
44.4;Problems;490
44.5;References;490
45;Chapter 39: Prodrugs;492
45.1;39.1. Introduction;492
45.2;39.2. Prodrug Design Differs with the ADME Process and Administration Route;494
45.3;39.3. Using Prodrugs to Improve Solubility;494
45.4;39.4. Prodrugs to Increase Passive Permeability;497
45.4.1;39.4.1. Ester Prodrugs for Carboxylic Acids;497
45.4.2;39.4.2. Ester Prodrugs for Alcohols and Phenols;499
45.4.3;39.4.3. Prodrugs Derived from Nitrogen-Containing Functional Group;500
45.5;39.5. Transporter-Mediated Prodrugs to Enhance Intestinal Absorption;500
45.6;39.6. Prodrugs to Reduce Metabolism;503
45.7;39.7. Prodrugs to Target Specific Tissues;504
45.8;39.8. Soft Drugs;504
45.9;Problems;505
45.10;References;505
46;Chapter 40: Effects of Properties on Biological Assays;508
46.1;40.1. Introduction;508
46.2;40.2. Effects of Insolubility IN DMSO;510
46.3;40.3. Dealing with Insolubility in DMSO;511
46.4;40.4. Effects of Insolubility in Aqueous Buffers;511
46.5;40.5. Dealing with Insolubility in Aqueous Buffers;513
46.5.1;40.5.1. Modify the Dilution Protocol to Keep Compounds in Solution;513
46.5.2;40.5.2. Assess Compound Solubility and Concentrations;513
46.5.3;40.5.3. Optimize Assays for Low-Solubility Compounds;514
46.5.4;40.5.4. Effects of Permeability in Cell-Based Assays;514
46.5.5;40.5.5. Dealing with Permeability in Cell-Based Assays;515
46.5.6;40.5.6. Effects of Chemical Instability in Bioassays;515
46.5.7;40.5.7. Dealing with Chemical Instability in Bioassays;515
46.6;Problems;515
46.7;References;516
47;Chapter 41: Formulation;518
47.1;41.1. Introduction;518
47.2;41.2. Routes of Administration;518
47.2.1;41.2.1. Oral (PO);519
47.2.2;41.2.2. Intravenous (IV);519
47.2.3;41.2.3. Intraperitoneal (IP);519
47.2.4;41.2.4. Subcutaneous (SC);520
47.2.5;41.2.5. Intramuscular (IM);520
47.3;41.3. Potency Drives Delivery Opportunities;520
47.4;41.4. Formulation Strategies;520
47.4.1;41.4.1. Adjust pH of Dosing Solution;521
47.4.2;41.4.2. Use Co-Solvent;521
47.4.3;41.4.3. Utilize Surfactants;522
47.4.4;41.4.4. Lipid-Based Formulation;523
47.4.5;41.4.5. Drug Complexation;525
47.4.6;41.4.6. Solid Dispersions;526
47.4.7;41.4.7. Particle Size Reduction;526
47.5;41.5. Practical Guide for Formulation in Drug Discovery;528
47.5.1;41.5.1. Formulation for PK Studies;528
47.5.2;41.5.2. Formulation for Toxicity Studies;529
47.5.3;41.5.3. Formulation for Pharmacological Activity Studies;529
47.6;Problems;529
47.6.1;Answers;530
47.7;References;530
48;Appendix I: Answers to Chapter Problems;532
48.1;Chapter 1—Introduction;532
48.2;Chapter 2—Benefits of Property Assessment and Good Drug-like Properties;532
48.3;Chapter 3—In Vivo Environments Affect Drug Exposure;532
48.4;Chapter 4—Prediction Rules for Rapid Property Profiling From Structure;533
48.5;Chapter 5—Lipophilicity;534
48.6;Chapter 6—pKa;535
48.7;Chapter 7—Solubility;535
48.8;Chapter 8—Permeability;536
48.9;Chapter 9—Transporters;537
48.10;Chapter 10—Blood-Brain Barrier;537
48.11;Chapter 11—Metabolic Stability;537
48.12;Chapter 12—Plasma Stability;538
48.13;Chapter 13—Solution Stability;539
48.14;Chapter 14—Plasma Protein Binding;539
48.15;Chapter 15—Cytochrome P450 Inhibition;540
48.16;Chapter 16—hERG Blocking;540
48.17;Chapter 17—Toxicity;541
48.18;Chapter 18—Purity and Integrity;541
48.19;Chapter 19—Pharmacokinetics;541
48.20;Chapter 20—Lead Properties;542
48.21;Chapter 21—Strategies for Integrating Drug-like Properties into Drug Discovery;542
48.22;Chapter 22—Methods for Profiling Drug-like Properties: General Concepts;542
48.23;Chapter 23—Lipophilicity Methods;543
48.24;Chapter 24—pKa Methods;543
48.25;Chapter 25—Solubility Methods;543
48.26;Chapter 26—Permeability Methods;544
48.27;Chapter 27—Transporter Methods;544
48.28;Chapter 28—Blood-Brain Barrier Methods;545
48.29;Chapter 29—Metabolic Stability Methods;545
48.30;Chapter 30—Plasma Stability Methods;545
48.31;Chapter 31—Solution Stability Methods;546
48.32;Chapter 32—CYP Inhibition Methods;546
48.33;Chapter 33—Plasma Tissue Binding Methods;546
48.34;Chapter 34—hERG Methods;546
48.35;Chapter 35—Toxicity Methods;547
48.36;Chapter 36—Integrity and Purity Methods;547
48.37;Chapter 37—Pharmacokinetic Methods;547
48.38;Chapter 38—Diagnosing and Improving Pharmacokinetic Performance;548
48.39;Chapter 39—Prodrugs;548
48.40;Chapter 40—Effects of Properties on Biological Assays;549
48.41;Chapter 41—Formulation;550
49;Appendix II;552
49.1;General Reference Books;552
50;Appendix III: Glossary;554
51;Index;572
52;Back Cover;582