Provides comprehensive coverage of microneedles for delivering and monitoring patient drugs and vaccines
Microneedles are an incredibly active research area and have the potential to revolutionize the way many medicines and vaccines are delivered. This comprehensive research book covers the major aspects relating to the use of microneedle arrays in enhancing both transdermal and intradermal drug delivery and provides a sound background to the use of microneedle arrays in enhanced delivery applications.
Beginning with a history of the field and the various methods employed to produce microneedles from different materials, Microneedles for Drug and Vaccine Delivery and Patient Monitoring discusses the penetration of the stratum corneum by microneedles and the importance of application method and force and microneedle geometry (height, shape, inter-needle spacing). Transdermal and intradermal delivery research using microneedles is comprehensively and critically reviewed, focusing on the outcomes of in vivo animal and human studies. The book describes the important topics of safety and patient acceptability studies carried out to date. It also covers in detail the growing area for microneedle use in the monitoring of interstitial fluid contents. Finally, it reviews translational and regulatory developments in the microneedles field and describes the work ongoing in industry.
- The only book currently available on microneedles
- Filled with tables, graphs, and black and white images (photographs, micrographs)
- Authored by four experts in pharmaceutics
Microneedles for Drug and Vaccine Delivery and Patient Monitoring is an ideal source for researchers in industry and academia working on drug delivery and transdermal delivery in particular, as well as for advanced students in pharmacy and pharmaceutical sciences.
Table of Contents
List of Contributors xi
About the Editors xiii
Preface xv
1 Genesis of Transdermal Drug Delivery 1
Ahlam Zaid-Alkilani
1.1 Skin Anatomy 2
1.1.1 The Epidermis 2
1.1.2 The Stratum Corneum 4
1.1.3 The Dermis 5
1.1.4 Skin Appendages 5
1.2 Routes to Percutaneous Drug Absorption 6
1.3 Facilitated Transdermal Drug Delivery 9
1.3.1 Electrical-based Devices 10
1.3.1.1 Iontophoresis 10
1.3.1.2 Electroporation 12
1.3.1.3 Ultrasound 12
1.3.1.4 Cryopneumatic and Photopneumatic Technologies 13
1.3.1.5 Velocity-based Devices 13
1.3.1.6 Thermal Approaches (Lasers and Radiofrequency Heating) 14
1.3.1.7 Microneedles 14
References 15
2 Microneedle Manufacturing and Testing 21
Eneko Larrañeta and Thakur Raghu Raj Singh
2.1 Introduction 21
2.2 Material Types, Properties and Biocompatibility 23
2.2.1 Silicon 23
2.2.1.1 Biocompatibility of Silicon 24
2.2.2 Metals 24
2.2.2.1 Biocompatibility of Metals 26
2.2.3 Ceramics 27
2.2.3.1 Biocompatibility of Ceramics 27
2.2.4 Silica Glass 28
2.2.4.1 Biocompatibility of Silica Glass 29
2.2.5 Carbohydrates 29
2.2.5.1 Biocompatibility of Carbohydrates 30
2.2.6 Polymers 30
2.2.6.1 Biocompatibility of Polymers 33
2.3 Microneedles Manufacturing and Design 35
2.3.1 Basics of Microfabrication 35
2.3.1.1 Lithography and Etching 36
2.3.1.2 Thin-film Deposition on Substrates 37
2.3.1.3 Etching 38
2.3.2 Microfabrication MNs 39
2.3.2.1 Fabrication of Silicon MNs 39
2.3.2.2 Fabrication of Metal and Glass MNs 42
2.3.2.3 Fabrication of Polymeric MNs 44
2.3.3 Microneedle Design 50
2.4 Microneedle Mechanical Characterisation 53
2.4.1 Axial Force Microneedle Mechanical Tests 54
2.4.2 Transverse Force and Shear Strength Microneedle Mechanical Tests 55
2.4.3 Baseplate Strength and Flexibility Tests 55
2.4.4 Microneedle Insertion Measurements 55
2.4.4.1 Staining of Microneedle-treated Skin 55
2.4.4.2 Transepidermal Water Loss Measurements 56
2.4.4.3 Electrical Impedance Measurements 56
2.4.4.4 Histological Tissue Staining and Sectioning 56
2.4.4.5 Confocal Microscopy 57
2.4.4.6 Optical Coherence Tomography 57
2.4.5 Significance of Microneedle Test Results 57
References 58
3 Microneedle-mediated Drug Delivery 71
Helen L. Quinn and Ryan F. Donnelly
3.1 Introduction 71
3.2 Microneedle Drug Delivery Strategies 73
3.2.1 Solid Microneedles 74
3.2.2 Coated Microneedles 77
3.2.3 Hollow Microneedles 78
3.2.4 Dissolving Microneedles 80
3.2.5 Hydrogel-forming Microneedles 83
3.3 Conclusion 85
References 85
4 Microneedle-mediated Vaccine Delivery 93
Maelíosa T.C. McCrudden, Aaron J. Courtenay and Ryan F. Donnelly
4.1 Introduction 93
4.2 Vaccine Delivery 93
4.2.1 Vaccination 93
4.2.2 Alternative Vaccine Delivery Options 96
4.3 Intradermal Vaccination 98
4.3.1 Skin Structure 98
4.3.2 Skin Immune Response 100
4.3.3 Conventional Strategies for Intradermal Vaccine Delivery 100
4.4 MN Delivery of Vaccine Therapeutics 101
4.4.1 Dissolving/Biodegrading Polymeric MNs 101
4.4.1.1 Viral Vaccines 102
4.4.1.2 Bacterial Vaccines 105
4.4.1.3 Model and Novel Vaccines 106
4.4.2 Hollow MNs 107
4.4.3 Solid MN 110
4.4.3.1 “Poke and Patch” Methodologies 110
4.4.3.2 Coated MNs 111
4.5 Future Perspectives 118
References 120
5 Microneedles for Gene Therapy: Overcoming Extracellular and Intracellular Barriers 129
Grace Cole, Nicholas J. Dunne and Helen O. McCarthy
5.1 Gene Therapy 129
5.2 DNA Vaccination 130
5.2.1 Advantages of DNA Vaccination 130
5.2.2 Mechanism of Action of DNA Vaccines 130
5.3 Treatment of Local Skin Diseases 135
5.4 Limitations of Gene Therapy 136
5.5 Microneedles as a Physical Delivery Strategy for Gene Therapy 138
5.5.1 Solid Microneedles 139
5.5.2 Coated Microneedles 143
5.5.3 Hollow Microneedles 147
5.5.4 Dissolvable Microneedles 148
5.5.5 Microneedles in Combination with Other Delivery Technologies 150
5.5.5.1 In Combination with Physical Delivery Technologies 150
5.5.5.2 In Combination with Vector-based Delivery Technologies 153
5.6 Conclusions 162
References 163
6 Delivery of Nanomedicines Using Microneedles 177
Eneko Larrañeta and Lalit Vora
6.1 Introduction 177
6.2 Skin Structure and Barrier Properties Which Impact on Nanoparticle and Microparticle Penetration 178
6.3 Conventional Nanocarriers for Topical and Transdermal Delivery 179
6.3.1 Lipidic Vesicles 179
6.3.2 Lipid Nanoparticles 181
6.3.3 Polymeric Nanoparticles and Microparticles 181
6.3.4 Microemulsions 181
6.3.5 Metallic and Mineral Nanoparticles 182
6.4 Microneedle-mediated Transdermal Delivery of Nanoparticles and Microparticles 183
6.4.1 Microneedle-assisted Nanoparticle/Microparticle Permeation 183
6.4.2 Drug Delivery 186
6.4.3 Vaccine Delivery 191
6.4.4 Other Uses 196
6.5 Conclusions 198
References 199
7 Minimally-invasive Patient Monitoring and Diagnosis Using Microneedles 207
Aaron J. Courtenay,Marco T.A. Abbate,Maelíosa T.C. McCrudden and Ryan F. Donnelly
7.1 Introduction 207
7.1.1 What is Patient Monitoring? 207
7.1.2 Why is Patient Monitoring Useful? 207
7.1.3 Limitations and Challenges of Therapeutic Monitoring 208
7.2 Sampling Techniques 209
7.2.1 Minimally and Non-invasive Sample Extraction 209
7.2.2 Microneedles and Fluid Sampling Technology 211
7.3 Microneedle Fluid Extraction Device Technical Considerations 211
7.3.1 Mechanical Parameters 211
7.3.2 Fluidics 212
7.4 Microneedle Innovations 212
7.4.1 Glucose Monitoring 213
7.5 Microneedle Innovations in Analyte Monitoring 218
7.5.1 Therapeutic Drug and Biomarker Detection 218
7.6 Microneedle Electrode Technology 219
7.6.1 Electro-biochemical Monitoring 219
7.7 Sampling and Analytical Systems Integration 221
7.7.1 Limitations and Challenges Associated with Systems Integration 221
7.8 Interstitial Fluid and Blood Sampling 223
7.8.1 Devices and Patents 223
7.9 Developments Moving Forwards 226
7.9.1 Industrialisation and Commercialisation: Hurdles to Overcome 226
7.10 Conclusion 228
References 229
8 Delivery of Photosensitisers and Precursors Using Microneedles 235
Mary-Carmel Kearney, Sarah Brown, Iman Hamdan and Ryan F. Donnelly
8.1 Introduction 235
8.1.1 Photodynamic Therapy 235
8.1.2 Photosensitisers 236
8.2 Topical Application of Photodynamic Therapy 237
8.3 Methods to Enhance Topical Photodynamic Therapy 238
8.3.1 Microneedle-mediated Photodynamic Therapy 239
8.3.2 PhotodynamicTherapy and Skin Pre-treatment Using Microneedles 239
8.3.3 Delivery of Photosensitisers Using Microneedles Containing the Active Agent 246
8.4 Microneedles and Photothermal Therapy 250
8.5 Conclusion 252
References 253
9 Microneedles in Improving Skin Appearance and Enhanced Delivery of Cosmeceuticals 259
Emma McAlister, Maelíosa T.C. McCrudden and Ryan F. Donnelly
9.1 Introduction 259
9.2 The Skin 259
9.3 Microneedling Technologies: An Evolutionary Step Towards MN Usage 260
9.4 Benefits of Microneedling 261
9.5 Commercially Available MN Devices 262
9.5.1 Dermaroller® 262
9.5.2 Beauty Mouse® 264
9.5.3 DermastampTM 265
9.5.4 Dermapen® 266
9.5.5 Light Emitting MN Devices 268
9.6 Patient Factors Relating to MN Devices 268
9.6.1 Acceptability of MN Devices by Patients and Healthcare Providers 269
9.6.2 Potential Irritation and Erythema 269
9.6.3 Patient Safety 269
9.6.4 Sterilisation Considerations 270
9.7 Delivery of Cosmeceutical Compounds 271
9.7.1 A Role for Hyaluronic Acid in MN Delivery Systems 271
9.7.2 MN-mediated Peptide Delivery 272
9.7.3 The Delivery of Other Cosmeceutical Agents 273
9.8 Recent Developments 275
9.8.1 Human Stem Cells 275
9.8.2 Fractional Radiofrequency 275
9.9 Conclusion 276
References 277
10 Microneedles for Ocular Drug Delivery and Targeting: Challenges and Opportunities 283
Ismaiel A. Tekko and Thakur Raghu Raj Singh
10.1 Introduction 283
10.2 Anatomy of the Eye and Barriers to Drug Delivery 284
10.2.1 The Anterior Segment and its Barrier Function 284
10.2.2 The Posterior Segment and its Barriers Function 286
10.3 Ocular Diseases and Treatments 288
10.4 Current Ocular Drug Delivery Systems and Administration Routes 288
10.4.1 Topical Route 288
10.4.2 Oral/Systemic Administration Route 288
10.4.3 Ocular Injections 290
10.4.3.1 Anterior Segment Injections 290
10.4.3.2 Posterior Segment Injections 291
10.5 Microneedles in Ocular Drug Delivery 293
10.5.1 Hollow MNs 293
10.5.2 Solid MNs with “Coat and Poke” Strategy 293
10.5.3 Dissolving MNs 295
10.5.4 Hollow MN Strategy 296
10.5.5 Other Strategies 299
10.6 MN Application Devices 299
10.7 MN Safety Concerns 300
10.8 Conclusion 301
References 302
11 Clinical Translation and Industrial Development of Microneedle-based Products 307
Ryan F. Donnelly
11.1 Introduction 307
11.2 Materials 308
11.3 Other Potential Applications 310
11.4 Patient Application 310
11.5 Patient/Healthcare Provider Acceptability 312
11.6 Patient Safety 313
11.7 Manufacturing and Regulatory Considerations 315
11.8 Commercialisation of MN Technologies 316
11.9 Conclusion 318
11.10 Future Perspectives 319
References 319
Index 323
