Preface ix ; Nomenclature xiii ; 1 Downstream Processing of Biotechnology Products ; 1.1 Introduction 1 ; 1.2 Bioproducts and Their Contaminants 2 ; 1.2.1 Biomolecular Chemistry and Structure 2 ; 1.2.1.1 Proteins 2 ; 1.2.1.2 Primary Structure 3 ; 1.2.1.3 Secondary Structure 6 ; 1.2.1.4 Tertiary Structure 11 ; 1.2.1.5 Quaternary Structure 11 ; 1.2.1.6 Folding 12 ; 1.2.1.7 Post-translational Modifications 12 ; 1.2.1.8 Oligonucleotides and Polynucleotides 16 ; 1.2.1.9 Endotoxins 18 ; 1.2.2 Biochemical and Biophysical Properties 20 ; 1.2.2.1 UV Absorbance 20 ; 1.2.2.2 Size 22 ; 1.2.2.3 Charge 26 ; 1.2.2.4 Hydrophobicity 28 ; 1.2.2.5 Solubility 31 ; 1.2.2.6 Chemical Stability 33 ; 1.2.2.7 Mechanical Stability 34 ; 1.2.2.8 Viscosity 35 ; 1.2.2.9 Diffusivity 38 ; 1.3 Bioprocesses 40 ; 1.3.1 Expression Systems 40 ; 1.3.2 Host Cell Composition 43 ; 1.3.3 Culture Media 44 ; 1.3.4 Components of the Culture Broth 45 ; 1.3.5 Product Quality Requirements 46 ; 1.3.5.1 Types of Impurities 48 ; 1.3.5.2 Validation 50 ; 1.3.5.3 Purity Requirements 51 ; 1.4 Biosimilars 52 ; 1.5 Role of Chromatography in Downstream Processing 53 ; 1.6 Environmental Impact of Biopharmaceutical Manufacturing 59 ; References 60 ; 2 Introduction to Protein Chromatography 63 ; 2.1 Introduction 63 ; 2.2 Basic Principles and Definitions 63 ; 2.3 Modes of Operation 67 ; 2.3.1 Elution Chromatography 69 ; 2.3.2 Frontal Analysis 70 ; 2.3.3 Displacement Chromatography 71 ; 2.3.4 Periodic Countercurrent and Simulated Moving Bed Separators (SMB) 72 ; 2.4 Performance Factors 76 ; 2.5 Separation Performance Metrics 81 ; 2.5.1 Column Efficiency 81 ; 2.5.2 Chromatographic Resolution 84 ; 2.5.3 Dynamic Binding Capacity 86 ; 2.5.4 Scaling Relationships 87 ; References 90 ; 3 Chromatography Media 93 ; 3.1 Introduction 93 ; 3.2 Interaction Types and Chemistry 94 ; 3.2.1 Steric Interaction 94 ; 3.2.2 Hydrophobic Interaction 96 ; 3.2.3 Electrostatic Interaction 103 ; 3.2.4 Metal Ion Interaction 106 ; 3.2.5 Biospecific Interaction 108 ; 3.2.6 Mixed Mode Interaction 113 ; 3.3 Buffers and Mobile Phases 117 ; 3.4 Physical Structure and Properties 118 ; 3.4.1 Base Matrices 119 ; 3.4.1.1 Natural Carbohydrate Polymers 121 ; 3.4.1.2 Synthetic Polymers 122 ; 3.4.1.3 Inorganic Materials 123 ; 3.4.2 Porosity, Pore Size, and Surface Area 125 ; 3.4.3 Particle Size and Particle Size Distribution 131 ; 3.4.4 Mechanical and Flow Properties 132 ; References 135 ; 4 Laboratory and Process Columns and Equipment 139 ; 4.1 Introduction 139 ; 4.2 Laboratory-Scale Systems 140 ; 4.2.1 Pumps 141 ; 4.2.2 Mixers 145 ; 4.2.3 Monitors 146 ; 4.2.4 System Volumes 149 ; 4.3 Process Columns and Equipment 150 ; 4.3.1 Columns 150 ; 4.3.2 Systems 155 ; 4.3.3 Column Packing 157 ; References 158 ; 5 Adsorption Equilibrium 159 ; 5.1 Introduction 159 ; 5.2 Single-Component Systems 161 ; 5.3 Multicomponent Systems 174 ; 5.4 Empirical Correlation of Equilibrium Data 178 ; 5.5 Protein Conformational Changes upon Adsorption 180 ; References 180 ; 6 Rate Processes 183 ; 6.1 Introduction 183 ; 6.2 Rate Mechanisms 183 ; 6.2.1 External Mass Transfer 185 ; 6.2.2 Pore Diffusion 188 ; 6.2.3 Solid Diffusion 192 ; 6.2.4 Intraparticle Convection 196 ; 6.2.5 Kinetic Resistance to Binding 201 ; 6.3 Batch Adsorption Kinetics 202 ; 6.3.1 General Rate Equations 204 ; 6.3.2 Analytical Solutions 206 ; 6.3.2.1 External Mass Transfer Control 207 ; 6.3.2.2 Solid Diffusion Control 207 ; 6.3.2.3 Pore Diffusion Control 208 ; 6.3.2.4 Binding Kinetics Control 210 ; 6.3.2.5 LDF Solution 210 ; 6.3.2.6 Combined Mass Transfer Resistances 211 ; 6.3.3 Experimental Verification of Transport Mechanisms 214 ; 6.3.4 Multicomponent Protein Adsorption Kinetics 218 ; References 223 ; 7 Dynamics of Chromatography Columns 227 ; 7.1 Introduction 227 ; 7.2 Material Balance Equations 227 ; 7.2.1 Boundary Conditions 229 ; 7.2.2 Dimensionless Equations 230 ; 7.3 Local Equilibrium Dynamics 231 ; 7.4 Multicomponent Systems 244 ; 7.5 Displacement Chromatography 256 ; 7.5.1 Prediction of the Isotachic Train 257 ; 7.5.2 Transient Development 262 ; References 263 ; 8 Effects of Dispersion and Rate Processes on Column Performance 265 ; 8.1 Introduction 265 ; 8.2 Empirical Characterization of Column Efficiency 265 ; 8.3 Modeling and Prediction of Column Efficiency 275 ; 8.3.1 Plate Model 275 ; 8.3.2 Rate Models with Linear Isotherms 278 ; 8.3.3 Rate Models with Nonlinear Isotherms 287 ; 8.3.4 Rate Models for Competitive Adsorption Systems 303 ; References 308 ; 9 Gradient Elution Chromatography 311 ; 9.1 Introduction 311 ; 9.2 General Theory for Gradient Elution with Linear Isotherms 313 ; 9.3 LGE Relationships and the Iso-resolution Curve in IEC 320 ; 9.3.1 Iso-resolution Curve 329 ; 9.4 LGE Relationships for RPC and HIC 332 ; 9.5 Gradient Elution at High Protein Loads 337 ; 9.6 Separations with pH Gradients 339 ; References 351 ; 10 Chromatographic Column Design and Optimization 355 ; 10.1 Introduction 355 ; 10.2 Chromatographic Process Steps and Constraints 357 ; 10.3 Design for Capture 361 ; 10.3.1 Load Step 362 ; 10.3.2 Wash Step 363 ; 10.3.3 Elution Step 364 ; 10.3.4 CIP Step 364 ; 10.3.5 Re-equilibration Step 365 ; 10.3.6 Productivity and Capacity Utilization 365 ; 10.3.7 Continuous Capture 370 ; 10.4 Design for Chromatographic Resolution 375 ; 10.5 SMB Design 382 ; References 391 ; Index 395.