A Handbook of Bioanalysis and Drug Metabolism

Cover......Page 1
ISBN-13: 9780415275194......Page 3
Editor’s Preface......Page 13
Preface......Page 14
Grieves Harnby: In Memoriam......Page 15
Contents......Page 5
1.1 Bioanalysis, Pharmacokinetics And Drug Metabolism ( Bpdm)......Page 17
1.2 The Role Of Bpdm In Drug Discovery And Drug Development......Page 18
2.1 Introduction......Page 24
2.2 The Physicochemical Nature Of Drug Molecules......Page 25
2.3 The Structure Of The Cell Membrane And Its Implications For Drug Disposition......Page 26
2.4 Drug Partitioning Across Membranes......Page 27
2.5 The Ionisation Of Drugs......Page 29
2.6.1 Absorption From The Stomach......Page 33
2.6.3 Distribution Across The Blood–brain Barrier......Page 35
2.7 The Importance Of The Physicochemical Properties Of Drugs To Their Metabolism And Excretion......Page 36
2.7.1 Cytochromes P- 450......Page 37
2.7.2 Glucuronidation......Page 38
2.7.3 Renal Drug Elimination......Page 39
2.8 Chirality And Its Effects On Drug Absorption, Metabolism And Excretion......Page 40
2.8.2 Differences In Distribution And Protein Binding Of Enantiomers......Page 41
2.8.4 Differences In The Renal Clearance Of Enantiomers......Page 42
2.9 The Importance Of Physicochemical Properties To The Analysis Of Drugs......Page 43
2.11 Bibliography......Page 45
3.2.1 Protein Precipitation......Page 48
3.2.2 Liquid–liquid Extraction......Page 49
3.2.3 Solid Phase Extraction......Page 50
3.3 Instrumentation......Page 51
3.4.1 Fully Automated Sample Preparation System......Page 52
3.4.2 Application......Page 55
3.4.3 Enhanced System......Page 56
3.5 Future Development......Page 58
3.6 References......Page 59
4.1 Introduction......Page 61
4.2 A Brief Look At The Theory Of Chromatographic Separation In Hplc......Page 62
4.3 The Basic Equipment Comprising A Modern Hplc System......Page 65
4.3.1 Pumps......Page 66
4.3.2 Autosamplers......Page 67
4.3.4 Detectors......Page 68
4.3.5 Data Handling Systems......Page 72
4.4.1 Normal Phase Liquid Chromatography......Page 73
4.4.2 Reversed Phase Liquid Chromatography......Page 74
4.4.3 Ion Exchange Chromatography......Page 76
4.4.4 Gradient High-performance Liquid Chromatography......Page 77
4.5 High- Throughput Bioanalysis......Page 80
4.6 Chiral Hplc......Page 81
4.7 Future Trends In Hplc......Page 82
4.8 Bibliography......Page 84
5.1 Introduction......Page 85
5.3 Analytical Interfaces......Page 86
5.3.1 Atmospheric Pressure–chemical Ionisation (apci)......Page 87
5.3.5 Thermospray......Page 88
5.4.2 Chemical Ionisation (ci)......Page 89
5.4.5 Atmospheric Pressure Chemical Ionisation (apci)......Page 90
5.5.3 Ion Trap Ms......Page 91
5.6 Use Of Ms In Quantitative Lc– Ms......Page 92
5.7.1 Example 1: A Semi-automated Method For The Determination Of Fluticasone Propionate (cci187811) In Human Plasma Using Solid Phase Extraction And Liquid Chromatography Tandem Mass Spectrometry......Page 93
5.7.2 Example 2: Sumatriptan (gr43175x) And Rizatriptan (gr289537x) In Human Plasma......Page 94
5.8.1 Mass Spectrometry Textbooks......Page 105
6.1 Summary......Page 106
6.2 The Role Of Immunoassay In Drug Discovery And Development......Page 107
6.3 Principles Of Immunoassay......Page 108
6.5 Production Of Reagent Antibodies......Page 111
6.6.1 Radiolabels......Page 112
6.6.2 Enzyme Labels......Page 113
6.7 Assay Development And Optimisation......Page 114
6.8 Assay Validation......Page 115
6.9 Immunoassays Developed In- House......Page 116
6.10 Commercial Kit Immunoassay......Page 118
6.12 Automation......Page 119
6.13 Biomarkers......Page 121
6.14 Case Study: Determination Of Cox- 2 Selectivity In Human Blood......Page 123
6.15 Biological Drugs......Page 124
6.16 References......Page 128
7.1 Introduction......Page 129
7.3 Bioavailability......Page 131
7.4 Calculation Of Pharmacokinetic Parameters......Page 132
7.4.1 Half-life......Page 133
7.4.2 Clearance......Page 134
7.4.3 Volume Of Distribution......Page 135
7.5.2 Terminal Phase Rate Constant ( Yz) And Half-life ( T1/2)......Page 136
7.5.3 Area Under The Plasma Concentration–time Curve ( Auclast And Auc1)......Page 137
7.5.6 Statistical Moment Theory ( Aumclast And Aumc1)......Page 139
7.5.7 The Mean Residence Time ( Mrt)......Page 140
7.6.1 Study Design......Page 141
7.7.1 Pharmacokinetic Screening Methods During Lead Optimisation......Page 143
7.8 Interspecies Scaling......Page 145
7.9 References......Page 147
8.1 The Importance Of Pharmacokinetic/ Pharmacodynamic Modelling......Page 148
8.2 Advantages Of Incorporating Pk/ Pd Modelling In The Drug Discovery Process......Page 149
8.3.2 Pk/ Pd......Page 150
8.3.3 Defining......Page 151
8.4.1 Data......Page 152
8.4.2 The......Page 153
8.4.3 Delayed......Page 154
8.4.4 Impact......Page 155
8.5 Summary......Page 156
8.6 References......Page 157
9.1 Introduction......Page 158
9.2 Study Design......Page 159
9.3.1 Cmaxss, Tmaxss......Page 162
9.3.2 Auct......Page 163
9.3.4 Time To Steady State And ‘effective Half-life’......Page 164
9.4 Reporting......Page 165
9.5 Application Of Toxicokinetic Data......Page 166
9.6 Toxicokinetic– Toxicodynamic Relationships......Page 167
9.7 Dose- And Time- Dependencies......Page 168
9.8 References......Page 171
10.1 Introduction......Page 172
10.3 Determinants Of The Unbound Fraction......Page 173
10.4 Principal Plasma Binding Proteins......Page 174
10.4.1 Human Serum Albumin (hsa)......Page 175
10.4.2 A1-acid Glycoprotein (aag)......Page 176
10.4.3 Lipoproteins......Page 177
10.5.1 Pharmacokinetics......Page 178
10.5.3 Protein-binding Displacement......Page 181
10.6.1 Equilibrium Dialysis......Page 182
10.6.2 Ultrafiltration......Page 183
10.7 Gv150526a: A Case History Of A Highly Bound Drug......Page 184
10.7.2 Use Of Radiolabel......Page 185
10.7.4 Linearity Of Protein Binding......Page 186
10.7.5 Toxicological Cover......Page 187
10.7.6 Protein-binding Displacement......Page 189
10.8 References......Page 191
11.1.1 Introduction......Page 192
11.1.2 Arsac......Page 194
11.3 Calculations......Page 197
11.3.1 Source Of Data......Page 198
11.3.2 Calculation Of Committed Effective Dose Equivalent (cede); Icrp 1977......Page 200
11.4 Accelerator Mass Spectrometry......Page 202
11.4.1 Sample Preparation For Ams......Page 203
11.4.2 Instrumental Details Of Ams......Page 204
11.5 Future Of Ams......Page 205
11.8 References......Page 206
12.1 Introduction......Page 207
12.3 Methodology......Page 208
12.4.3 Time Point Selection......Page 209
12.5.2 Sectioning......Page 210
12.6 Imaging......Page 211
12.7 Quantitative Whole Body Autoradiography......Page 212
12.8.1 Absorption/distribution......Page 213
12.8.2 Excretion......Page 214
12.8.4 Residues And Toxicity......Page 215
12.8.5 Therapeutic Activity......Page 217
12.8.6 Reproductive Toxicology Studies......Page 219
12.8.7 Human Dosimetry Studies......Page 221
12.9 References......Page 222
13.1 Introduction......Page 224
13.2 Cytochrome P450s......Page 225
13.3 Monoamine Oxidases ( Mao)......Page 231
13.4 Flavin Monooxygenases ( Fmo)......Page 232
13.6.2 Aldehyde Oxidase (ao)......Page 234
13.6.3 Epoxide Hydrolase......Page 235
13.6.5 Carbonyl Reductases......Page 236
13.7 Conclusions......Page 237
14.1 Introduction......Page 238
14.2 Phase Ii Enzyme Reactions......Page 239
14.2.1 Glucuronidation......Page 240
14.2.2 Sulphation......Page 241
14.2.3 Methylation......Page 243
14.2.4 Acetylation......Page 244
14.2.5 Amino Acid Conjugation......Page 245
14.2.6 Glutathione Conjugation......Page 246
14.3.1 Udp-glucuronosyltransferase (ugt) Nomenclature......Page 248
14.3.2 Sulphotransferase (sult) Nomenclature......Page 249
14.3.3 N-acetyltransferase (nat) Nomenclature......Page 250
14.3.4 Glutathione-s-transferase (gst) Nomenclature......Page 251
14.4.1 Toxicity Of Conjugated Metabolites......Page 252
14.4.2 Stereoselectivity In Metabolism By Phase Ii Enzymes......Page 253
14.4.3 Polymorphisms In Phase Ii Enzymes......Page 254
14.4.4 Drug–drug Interactions......Page 255
14.5 Summary......Page 257
14.6 References......Page 258
15.1 Introduction......Page 260
15.2.1 Preparation Of Subcellular Fractions......Page 263
15.2.2 Preparation Of Hepatocytes......Page 265
15.2.3 Preparation Of Liver Slices......Page 269
15.3.1 Subcellular Fractions......Page 270
15.3.3 Liver......Page 271
15.4 In Vitro–in Vivo Correlations......Page 272
15.4.1 Venous Equilibrium Model......Page 273
15.5.1 Subcellular Fractions......Page 274
15.5.2 Hepatocytes......Page 276
15.6.1 Drug–drug Interactions: Subcellular Fractions And Hepatocytes......Page 277
15.6.2 Drug Interactions: Monolayer Culture Of Hepatocytes......Page 278
15.6.4 Other In Vitro Models......Page 281
References......Page 282
16.1 Introduction......Page 285
16.3 The Impetus Behind An In Vitro Approach......Page 286
16.4 The Mechanism Behind Drug– Drug Interactions......Page 287
16.5 Drug- Metabolising Enzymes......Page 288
16.6 Drug Transport Systems......Page 289
16.7 Plasma Protein Binding......Page 290
16.9 Inhibition Of Drug- Metabolising Enzymes And Its Effect......Page 291
16.10 Induction Of Drug- Metabolising Enzymes And Its Effect......Page 296
16.11.1 The Intact Hepatocyte Systems......Page 297
16.11.2 Microsomes......Page 298
16.11.3 Sources Of Human Tissue......Page 299
16.11.4 Genetically Engineered Drug-metabolising Enzymes......Page 300
16.13.1 Terfenadine......Page 302
16.13.3 Losartan......Page 303
16.13.6 Terbinafine......Page 304
16.14 Overview......Page 305
16.15 References......Page 306
17.1 Introduction......Page 308
17.2 Mass Spectrometry......Page 309
17.3 Sample Preparation......Page 310
17.4 Phase I......Page 311
17.5 Phase II......Page 317
17.6 Nmr Spectroscopy......Page 326
17.6.1 Sample Preparation And Isolation......Page 329
17.7.1 Phase I......Page 330
17.7.2 Phase Ii......Page 334
17.9 Conclusions......Page 338
18.2 Basic Molecular Biology......Page 341
18.4.1 Introduction......Page 345
18.4.2 Why Use Expressed Enzymes?......Page 346
18.4.3 Choice Of Expression Systems......Page 347
18.5.2 Determination Of Changes In Protein Levels......Page 357
18.5.3 Determination Of Changes In Mrna Levels......Page 359
18.5.4 Determination Of Changes In Gene Transcription......Page 364
18.6.2 Polymorphisms And Microheterogeneity......Page 365
18.6.4 Detection Of Polymorphisms......Page 366
18.7 References......Page 368
18.8 Bibliography......Page 374
19.1 Introduction......Page 375
19.2 The First Principle: Potency Versus Efficacy......Page 377
19.4 Assessment Of Absorption And Systemic Availability......Page 379
19.5 Cell- Based Models Of Absorption......Page 383
19.6 The Importance Of Clearance......Page 384
19.7 Distribution And Protein Binding......Page 387
19.8 Half- Life And Duration Of Action......Page 388
19.9 Modifying Structures To Block Metabolism......Page 389
19.10 What Do We Do About Inhibitors And Inducers?......Page 391
19.11 What Does The Ideal Drug Look Like?......Page 392
19.12 The Future......Page 393
19.14 References......Page 395