Table of Contents
Preface v
Contributors xiii
1 The History of Pharmaceutical Photostability Development Joseph T. Piechocki 1
Introduction 1
Surveys 26
International Conference on Harmonization Guideline Development 29
References 33
2 The International Conference on Harmonization Photostability Guideline Hanne Hjorth Tønnesen 47
Introduction 47
ICH Guideline 47
Guideline Problems 48
Conclusion 59
References 59
3 Terminology Joseph T. Piechocki 61
Introduction 61
General Terminology 61
ICH Sources 71
Conclusion 76
References 76
4 Basic Principles of Drug Photostability Testing John M. Allen Sandra K. Allen 79
Introduction 79
Basic Concepts 79
Photoreactivity 80
Kinetics of Drug Photoreactions 82
Actinometry 82
Physical Composition of Samples 83
Protection of Photolabile Drugs 84
International Committee for Harmonization Guideline 84
Conclusions 85
References 86
5 Spectra Joseph T. Piechocki 87
Introduction 87
Emission Spectra 87
Incident Radiation 89
Absorption Spectra 90
Spectral Power Distributions 95
Summary 96
References 97
6 Sources Joseph T. Piechocki 99
Introduction 99
International Conference on Harmonization Options 99
Individual International Conference on Harmonization Lamp Classes 100
Source Selection Criteria 110
Lamp Studies 115
Alternative Lamps 116
Conclusion 116
References 117
7 Glasses, Filters, and Containers Joseph T. Piechocki 121
Introduction 121
Glasses 121
Filters 128
Containers 132
Summary 134
References 136
8 Chemical Actinometry Günter Gauglitz Stephan M. Hubig 139
Introduction 139
Measurement of Light Flux (Intensity) 140
Photokinetic Principles 141
Selected Chemical Actinometers 145
Special Applications 153
References 161
9 Radiometry/Photometry Robert Angelo 165
Electromagnetic Spectrum 165
Radiometric and Photometric Concepts and Units 165
Quality of Measurement 168
Photostability 174
Summary 176
References 176
10 Sample Presentation for Photostability Studies: Problems and Solutions Steven W. Baertschi Scott R. Thatcher 177
Introduction 177
Types of Studies 177
Photolysis Sources or Chambers 178
Containers 189
Drug Substance 194
Drug Products 198
Generic Drugs 199
Conclusion 199
References 200
11 Determining the Kinetics and Mechanism of a Photochemical Reaction Douglas Moore 203
Reaction Kinetics and Photostability 203
Kinetics of Photosensitized Reactions 211
Application of Kinetic Measurements to Reaction Mechanism Determination in Photostability 212
References 220
12 Unexpected Photochemistry in Pharmaceutical Products: A Review on the Role of Diluents, Excipients, and Product Components in Promoting Pharmaceutical Photochemistry Allen C. Templeton William E. Bowen Lee J. Klein Paul A. Harmon Yu Lu Robert A. Reed 223
Introduction 223
Diluent Mediated Photochemistry 225
Excipient Mediated Photochemistry 227
Product Component Mediated Photochemistry 244
Conclusion 248
References 248
13 Chambers and Mapping Joseph T. Piechocki 253
Introduction 253
Testing Apparatus/Chambers 253
Fluorescent Lamp Chambers 256
Environmental Growth Chambers (EGC) 259
Xenon Chambers 269
Metal Halide Lamps 273
Mapping 277
Conclusion 290
References 290
14 Current Methods for the Analytical Investigation of the Photodegradation of Active Pharmaceutical Ingredients and Products Karl Thoma Norbert Kübler 293
Introduction 293
Procedure for Photostability Exposure 293
Analytical Methods for Photostability Testing 297
HPLC Systems 302
Conclusion 302
References 303
15 Photostabilization by Packaging Karl Thoma Wolfgang Aman 305
Introduction 305
Glasses 305
Plastics 310
Other Packaging 317
Conclusion 319
References 319
16 Photostabilization of Solid and Semisolid Dosage Forms Karl Thoma Heiko Spilgies 323
Photostabilization as Part of the Drug Formulation 323
Photostabilization of Tablets 329
Photostabilization of Capsules 334
Photostabilization of Dermal Preparations 336
Conclusion 341
References 342
17 Photostability Studies of Solutions and Methods of Preventing Photodegradation Ahmed F. Asker 345
Introduction 345
Photodegradation Effect 345
Routes of Photochemical Degradation 347
Photostability Testing 349
Factors Affecting Photodegradation in Solutions 351
Protection Techniques 365
Conclusion 372
References 373
18 Photostability of Cosmetic Sunscreens Hans U. Gonzenbach 379
Introduction 379
Photostability of Sunscreens 382
UV Filters and Their Photochemistry 383
Determination of Photostability 388
Photostabilization 390
Synopsis 393
References 395
19 Photodegradation and Photoprotection in Clinical Practice Irene Krämer 397
Introduction 397
Photodegradation and Photoprotection During Administration 398
Photodegradation of Selected Drugs and Management of Photoprotection During Administration 403
Total Parenteral Nutrition Solutions 419
Conclusion 423
References 423
Index 429
