NMR Spectroscopy in Pharmaceutical Analysis (eBook)

Front Cover 1
NMR Spectroscopy in Pharmaceutical Analysis 4
Copyright Page 5
Table of Contents 6
Preface 16
List of Contributors 18
List of Editors 22
Part I FUNDAMENTALS AND TECHNIQUES 24
Chapter 1 Principles in NMR Spectroscopy 26
1 Short History 27
2 The NMR Experiment 28
2.1 Excitation, relaxation and sensitivity 28
2.2 Relaxation 30
3 Chemical Shift 33
3.1 Electronic density 33
3.2 Anisotropy 34
3.3 Mesomerism 36
3.4 Steric effects 36
4 Calibration and Relative Scale ppm 37
5 Spin–Spin Coupling 38
5.1 The coupling constant 38
5.2 Multiplicity 39
5.3 Roof effect 40
5.4 Angular dependence of the coupling constant 41
5.5 Heteronuclear coupling 41
5.6 13C NMR satellites in 1H NMR spectra 44
6 Heteronuclear Spectra 44
6.1 Decoupling 45
6.2 Quantitative heteronuclear NMR 45
7 Molecular Dynamics 46
7.1 Deuterium exchange and solvent effects 47
8 Chemical Derivatisation 50
9 Stereochemistry 51
9.1 Diastereomerism 51
9.2 Atrop or axial chirality 52
9.3 Enantiomeric excess 52
9.4 Diastereotopy 53
10 Two-dimensional Methods for Structure Elucidation 56
11 Experimental Data 63
Chapter 2 Quantitative NMR in the Solution State NMR 66
1 Introduction 67
2 Basics 67
3 Quantitative NMR Spectroscopy 68
3.1 Relative method 68
3.2 Absolute method 69
4 Validation 70
4.1 Linearity 71
4.2 Robustness 72
4.3 Specificity and selectivity 75
4.4 Accuracy 76
4.5 Precision 77
4.6 Measurement uncertainty 78
4.7 Round robin tests 79
5 Sensitivity 82
6 Conclusion 83
Chapter 3 qNMR in Solid State 86
1 Introduction to Solid-state NMR 86
2 Quantitative Aspects of Solid-state NMR, Protocol for Quantitation 93
3 An Example: Quantitation of Pseudoephedrine in Dosage Form 96
4 Quantitation of Polymorphs and Formulated Drugs 101
Chapter 4 Microcoil Nuclear Magnetic Resonance Spectroscopy 106
1 Introduction 107
2 Intrinsic NMR Sensitivity 107
3 Development of Small Coils for High-Resolution NMR 109
3.1 Saddle/Helmholtz coils 109
3.2 Solenoidal coils 110
3.3 Planar RF coils 115
3.4 Novel microcoil designs 116
3.5 High-temperature superconducting microprobes 118
4 Sensitivity Comparisons 120
5 Nanoliter Volume Applications of RF Microcoils – Hyphenated cITP–NMR 121
6 Microliter Volume Applications of RF Microcoils 124
6.1 Helmholtz/saddle coils 124
6.2 Solenoidal coils 124
6.3 Superconducting microcoils 127
7 Hyphenation of Microseparation Techniques with Microliter NMR Detection 131
8 Multiple Coil Probeheads 140
9 Solid-State Applications of Small Coils 146
10 Conclusion 148
Chapter 5 qNMR Spectroscopy in Drug Analysis – A General View 154
1 Introduction 154
2 NMR Spectroscopy in International Pharmacopoeias 155
2.1 Identification of drugs 156
2.2 Tests 156
2.3 Assay 158
3 Validation 158
4 Conclusions 159
Part II GENERAL APPLICATIONS 162
Chapter 1 Investigation of Multi-Component Drugs by NMR Spectroscopy 164
1 Introduction 164
1.1 Solvent 165
1.2 pH value 166
1.3 Temperature 167
1.4 Auxiliary reagents 167
1.5 Limitations 168
2 Codergocrine Mesylate 169
2.1 1H NMR spectroscopy 169
2.2 13C NMR spectroscopy 173
2.3 High-performance liquid chromatography 175
2.4 HPLC versus NMR spectroscopy 176
Chapter 2 NMR Applications for Polymer Characterisation 180
1 Introduction 180
2 Polydimethyl Siloxane 181
3 Polysaccharides 184
4 Polyether Formulation Aids 188
5 Formaldehyde 193
6 Polyester 196
7 Poly- and Oligopeptides 197
8 Polyvinyl Compounds 201
9 Experimental Data 202
Chapter 3 NMR Spectroscopy of Natural Substances 204
1 Introduction 204
2 Characterisation of Natural Substances as a Finger Print Analysis 205
3 Characterisation of Natural Substances According to Single Target Molecules 207
4 Characterisation and Definition of Primary Reference Standards 210
5 Multi-Component Analysis of Complex Natural Substance Mixtures and Phytopharmaceutics 214
5.1 Extracts from medical plants 214
5.2 Lipids 216
5.3 Lecithin 217
5.4 Fats and oils 220
6 Experimental Data 223
Chapter 4 Solid-State Measurements of Drugs and Drug Formulations 224
1 Solid-state NMR in Pharmacy 225
2 Solid-state NMR Measurements of Drugs 227
2.1 Amphetamine and ephedrine hydrochlorides and related compounds 227
2.2 Erythromycin A – formation of a hemiketal 228
2.3 Paracetamol – characterization of polymorphic forms 229
2.4 Procaine and procainamide derivatives 230
2.5 Rifampicin – molecular structure of polymorphs 230
2.6 Ketoconazole – amorphous form required 231
2.7 Paclitaxel (Taxol) – molecular structure and interactions 232
2.8 Troglitazone – hydration of diastereomers 233
2.9 Delavirdine mesylate tablets – hydration and solubility 233
2.10 MAS NMR of steroids: finasteride, estradiol, testosterone 233
2.11 Nifedipine and amlodipine 235
2.12 Ibuprofen preparations 238
2.13 Sildenafil citrate (Viagra) – structure and hydrogen bonding 239
2.14 Oxybuprocaine hydrochloride – NMR crystallography 239
2.15 Bupivacaine in protein matrix 240
2.16 Warfarin – cyclic hemiketal 240
3 Medicinal Plants Extracts 241
3.1 Mixture of a-amyrin and ß-amyrin 241
3.2 Euphol from Euphorbia 242
3.3 Oxindole alkaloids from Uncaria tomentosa 244
3.4 Lanatoside C 246
3.5 Curcumin 248
4 13C CPMAS NMR of Excipients 248
5 Drugs in Membranes 251
Chapter 5 Metabolic Profiling 256
1 Introduction 257
1.1 Definition of metabolic profiling 257
1.2 Goals of metabolic profiling experiments 257
1.3 Dynamic range of NMR measurements 258
1.4 Scope of chapter 259
2 Sample Preparation 259
2.1 General considerations 259
2.2 Sample specific considerations 263
2.3 Tissues 266
3 Data Acquisition 269
3.1 Requirements for quantitative NMR measurements 271
3.2 Water suppression 271
3.3 Experiments utilizing nuclei other than 1H 272
4 Spectral Processing 274
4.1 Apodization 274
4.2 Phasing and baseline correction 275
4.3 Selection of integral regions 277
4.4 Peak alignment 279
4.5 Normalization 280
4.6 Centering, scaling, and transformation 281
5 Illustration 282
6 Conclusions and Future Perspectives 285
Chapter 6 DOSY NMR for Drug Analysis 292
1 Introduction 292
2 Theory 293
2.1 DOSY 293
2.2 TOSY 298
3 Applications to the Analysis of Drug Formulations 300
3.1 DOSY 1H NMR analysis of ciprofloxacin formulations 300
3.2 DOSY 1H NMR analysis of oral formulations of fluoxetine 302
3.3 DOSY 1H NMR analysis of formulations of genuine Cialis® and a Chinese imitation 303
3.4 DOSY 1H NMR analysis of an herbal Chinese formulation 305
3.5 TOSY NMR analysis of ibuprofen 306
4 Advantages and Drawbacks of the Methods 307
5 Conclusion 310
Chapter 7 The Use of qNMR for the Analysis of Agrochemicals 314
1 Introduction 315
2 Limitations of Present Methods for Analysis of Technical Grade Materials 315
2.1 Purity and supply of standard reference materials 315
2.2 Limitations of chromatographic methods 317
2.3 Shortcomings of some official agrochemical analytical methods 317
3 Analysis of the Active Ingredient in Agrochemicals by qNMR 318
3.1 General considerations 318
3.2 qNMR using the subtraction method 319
3.3 qNMR using a standard of known purity 320
3.4 The concept of universal standard reference material 321
3.5 Practical analysis of technical grade agrochemicals by qNMR 322
4 qNMR Analysis of Proscribed Impurities in Agrochemicals 332
5 qNMR Analysis of Manufacturing Impurities in Agrochemicals 334
6 Conclusion 337
Part III SPECIAL APPLICATIONS 340
Chapter 1 NMR-Based Mixture Analysis on the Example of Fruit Juice Quality Control Using Statistics and Quantification 342
1 Introduction 343
2 Instrumental Aspects of Fruit Juice Quality Control 345
3 Identification of Compounds in the Mixture 349
4 Quantification of Compounds in Fruit Juice Spectra 350
5 Ridge-Regression in Fruit Juice Quality Control 352
6 Statistical Analysis on Fruit Juices Other than Ridge Regression 353
7 Information on the Statistical Methods Applied 359
8 Conclusion 360
Chapter 2 NMR Assays for Carbohydrate-Based Vaccines 364
1 Vaccines Based on the Cell Surface Carbohydrates of Microbial Pathogens 365
1.1 Cell surface carbohydrates 366
1.2 Carbohydrate-based vaccines 366
1.3 The structures of bacterial polysaccharides 367
2 NMR Tests for the Identity and Purity of Polysaccharides Used in Vaccine Manufacture 368
2.1 Traditional chemical approaches 368
2.2 Polysaccharide identity determination by NMR spectroscopy 370
2.3 NMR analysis of blends and CPSs in the presence of excipients 373
2.4 Quantitation of the O-acetyl contents of CPSs 374
2.5 Quantitation of contaminants and process-related impurities 375
2.6 Polysaccharide quantification 377
3 Identification of End Groups as Markers of Polysaccharide Degradation 377
4 Characterisation of Activated Intermediates in Vaccine Manufacture 379
4.1 Combined activation and depolymerisation using periodate oxidation or acid hydrolysis 380
4.2 Random activation without depolymerisation 381
5 NMR Analysis of Glycoconjugate Vaccines 383
5.1 Identity and integrity of the saccharide component of glycoconjugate vaccines 383
5.2 Determination of polysaccharide–protein ratio in glycoconjugate vaccines 385
6 Conclusions 387
Chapter 3 Fluorine-19 or Phosphorus-31 NMR Spectroscopy: A Powerful Technique for Biofluid Metabolic Studies and Pharmaceutical Formulation Analysis of 392
1 Introduction 393
2 Advantages and Limitations of 19F and 31P NMR for in vitro Studies 394
3 19F NMR Studies of Fluorinated Drugs 396
3.1 Anti-bacterials 396
3.2 Neuroleptics 398
3.3 Analgesics 399
3.4 Anti-inflammatory drugs 399
3.5 Anaesthetics 400
3.6 Anti-cancer drugs 405
3.7 Anti-fungals 415
3.8 Miscellaneous drugs 417
4 31P NMR Studies of Phosphorylated Drugs 417
4.1 Amifostine 417
4.2 Cyclophosphamide and ifosfamide 418
5 Conclusion 424
Chapter 4 Quantitative 2D NMR Analysis of Glycosaminoglycans 430
1 Introduction 430
1.1 GAGs characterization via 1D NMR 434
2 2D NMR Approach 437
2.1 Setup of the 2D NMR method 438
2.2 Choice of analytical signals 440
2.3 2D analysis of a simple oligosaccharide mixture 442
3 Low-Molecular-Weight Heparin Analysis 444
4 Conclusions 450
Chapter 5 The Use of Proton NMR as an Alternative for the Amino Acid Analysis as Identity Test for Peptides 452
1 Introduction 452
2 Spectral Comparison 453
3 Conclusions 458
Chapter 6 Assessment of the Inhibitory Potency of Antibiotics by MRI 460
1 Introduction 460
2 Current Status of NMR Spectroscopy and MRI 461
3 High Throughput in NMR 462
4 Investigation of Bacterial Cultures by NMR Spectroscopy 463
5 Assessment of the Inhibitory Potency of Antimicrobials 463
6 Assessment of the Inhibitory Potency by MRI 465
6.1 Spatial resolution and parallelization 466
6.2 Marker of bacterial growth 466
6.3 NMR growth curves and determination of the MIC 468
Chapter 7 Hypernation and Concatenation: Multiple On-Line Spectroscopic Analysis for Drug and Natural Product Characterisation 472
1 Introduction 472
2 Concatenated FIA Systems 474
3 Hybrid Concatenated/Hypernated FIA–MS/LC–NMR Systems 477
4 Hypernated LC–UV–NMR–MS Combinations 478
5 LC–NMR–MS with Superheated D2O as the Eluent 482
6 LC–NMR and LC–NMR–MS with On-Line Collection for Off-Line IR 483
7 Fully On-Line LC–UV–NMR–IR–MS Systems 484
8 LC–UV–IR–NMR–MS with Hot and Superheated D2O as the Eluent 485
9 The Practice of Concatenation and Hypernation 489
10 Conclusions 490
Chapter 8 Quantitative High-Resolution Online NMR Spectroscopy in Pharmaceutical Reaction and Process Monitoring 494
1 Introduction 495
2 Quantitative Flow NMR Spectroscopy 495
2.1 Technical samples on flow 496
2.2 Deuterium-free samples and solvent suppression techniques 496
2.3 Solvent suppression techniques 497
2.4 Reacting samples 498
2.5 Flowing samples 498
2.6 Acquisition 499
2.7 Peak deconvolution 499
3 Online NMR Spectroscopy 500
3.1 Field homogeneity 500
3.2 Flow scheme 501
3.3 Hyphenation 502
3.4 Residence times 502
4 Examples 505
4.1 Ester formation kinetics 505
4.2 Hydroxymethylation of urea 508
4.3 Pharmaceutical R& D – chemistry
5 Conclusions and Outlook 513
Index 516