TABLE OF CONTENTS S. No. Description Page No. CHAPTER-I 1.0 Introduction 1 CHAPTER-II 2.0 Literature Review 5 2.1 History 6 2.2 Formulation Theory 7 2.3 Properties of Nanoparticles 9 2.4 Existing Technologies To Produce Drug Nanoparticles 9 2.4.1 Bottom up Technologies (Precipitation Methods) 10 2.4.2 Top Down Technologies 12 2.4.2.1 High Pressure Homogenization Methods 12 2.4.2.2 Microfluidisation for Production of Drug Nanoparticles 2.4.3 Piston gap Technologies 13 2.4.4 Milling Methods 14 2.5 Conversion of Nanosuspension in to Solid Intermediate 18 2.6 Characterization of Nanoparticles 19 2.7 Particle Size and Size Distribution 19 2.7.1 Spectroscopy 19 2.7.2 Microscopy 21 2.7.3 Morphology 22 2.7.3.1 Differential Scanning Calorimetry (DSC) 22 2.7.3.2 X-ray Powder Diffraction (XRPD) 22 2.7.4 Interparticular Interactions 22 2.8 Drug Candidate Selection Criteria 23 2.9 Objective of the Investigation 24 12 vii
2.10 Scope 24 2.11 Plan of Work 25 CHAPTER-III 3.0 Experimental Investigations 27 3.1 Candesartan cilexetil Drug Profile 28 3.1.1 Pharmacokinetics 29 3.1.2 Mechanism of Action 29 3.1.3 Dose 30 3.2 Materials and Methods 31 3.2.1 Materials 32 3.2.2 Instruments and Apparatus 33 3.3 Solubility Studies 34 3.3.1 ph solubility Study 34 3.4 Preparation of Nanosuspension using In-house Fabricated Equipment 34 3.5 Formulation Design 35 3.6 Selection of Primary Stabilizer 36 3.7 Selection of Secondary Stabilizer 36 3.8 Evaluation of Nanosuspension 43 3.8.1 Method Development for Particle Size Analysis by Laser Diffraction Technique 3.8.2 Principle and Working of Malvern Mastersizer 43 3.8.3 Method Development for Particle Size Analysis 44 3.8.3.1 Representative Sampling 45 3.8.3.2 Use of Dispersant 45 3.8.3.3 Sample Concentration 45 3.8.3.4 Solid Particle Measurements 46 3.8.3.5 Analysis Procedure 46 43 viii
3.8.4 Specifications for Particle Size Measurement in Malvern Mastersizer 3.9 Scale-up of Milling Process using Agitator Bead Mill (Netzsch ) 48 3.9.1 Principle and Working of Netzsch Lab Star Bead Mill 48 3.9.2 Grinding Media Size and Composition 50 3.10 Conversion of Nanosuspension in to Solid Intermediates 52 3.10.1 Process Selection 52 3.10.1.1 Lyophilization Technique 52 3.10.1.2 Drug Layering 52 3.10.1.3 Spray Drying 52 3.10.2 Selection of Suitable Carrier 53 3.11 Solid State Characterization 55 3.11.1 Differential Scanning Calorimetry (DSC) 55 3.11.2 Powder X-Ray Diffraction (PXRD) 55 3.12 Optical Microscopic Examination 55 3.13 Scanning Electron Microscopy (SEM) 56 3.14 Analytical Methodology 56 3.14.1 Analytical Method Development for Estimation of Candesartan in Formulations 3.14.2 Drug Content Estimation by HPLC 56 3.14.2.1 Chromatographic Conditions 57 3.14.2.2 Standard Preparation 58 3.14.2.3 Sample Preparation 59 3.14.2.4 System Suitability 59 3.14.2.5 Calculations 59 3.14.3 Saturation Solubility of Nanoparticles 60 3.15 Tablet Preparation 60 3.15.1 Selection of Tableting Excipients 60 3.15.2 Preparation of Tablets using Candesartan cilexetil Granules 61 ix 47 56
3.16 Evaluation of Blend Physical Properties 62 3.16.1 Angle of Repose 62 3.16.2 Density 62 3.16.3 Carr s Index 63 3.16.4 Hausner Ratio 63 3.17 Evaluation of Tablet Physical Properties 63 3.17.1 Average Weight 64 3.17.2 Tablet Thickness 64 3.17.3 Tablet Hardness 64 3.17.4 Friability 64 3.17.5 Disintegration Time 64 3.17.6 Moisture Content 64 3.17.7 Dissolution Studies 65 3.17.7.1 Apparatus 65 3.17.7.2 Dissolution Conditions 66 3.17.7.3 Calculations 66 3.18 In-Vivo Pharmacokinetic Study 67 3.18.1 Bioanalysis by LC-MS 68 3.18.2 Chromatographic Conditions 69 3.18.3 Sample Preparation 69 3.19 Stability Evaluation 70 3.20 Results and Discussion 71 3.20.1 Solubility Studies 72 3.20.2 Preparation of Nanosuspension Using Wet Milling Apparatus 72 3.20.3 Stabilizer Screening for Production of Physically Stable Nanosuspensions 3.20.4 Scale-up of Nanosuspension Process using Media Mill 79 73 x
3.20.4.1 Effect of Process Time 80 3.20.5 Spray Drying Processes for Conversion of Nanosuspension into Solid Intermediate 3.20.6 Optical Microscopic Examination 84 3.20.7 Scanning Electron Microscopy (SEM) 85 3.20.8 Solid State Characterization 86 3.20.9 Solubility Studies of Un-milled, Micronized and Drug Nanoparticles 3.20.10 Preparation of Tablets 90 3.20.11 Physical Properties of Blend 90 3.20.12 Compression into Tablets 92 3.20.13 Dissolution Rate Evaluation 94 3.20.14 In-Vivo Evaluation 97 3.20.15 Stability Evaluation 98 3.21 Camptothecin Analog 100 3.21.1 Camptothecin Analog Drug Profile 101 3.21.2 Mechanism of Action 103 3.21.3 Dose 103 3.22 Material and Methods 104 3.22.1 Materials 105 3.22.2 Instruments and Apparatus 106 3.23 Solubility Studies 107 3.23.1 ph solubility Study 107 3.24 Preparation of Nanosuspension using in-house fabricated equipment 107 3.25 Formulation Design 108 3.26 Selection of Primary Stabilizer 108 3.27 Selection of Secondary Stabilizer 109 3.28 Evaluation of Nanosuspension 116 3.28.1 Particle Size Analysis using Malvern Mastersizer 116 xi 82 89
3.28.2 Specifications for Particle Size Measurement in Malvern Mastersizer 3.29 Scale-Up of Manufacturing Process using Agitator Bead Mill 117 3.29.1 Preparation of Nanosuspension 117 3.30 Conversion of Nanosuspension into Solid Intermediate 118 3.30.1 Process Selection 118 3.30.2 Spray Granulation Process 119 3.30.3 Selection of Suitable Carrier 119 3.31 Solid State Characterization 121 3.31.1 Differential Scanning Calorimetry (DSC) 121 3.31.2 Powder X-ray Diffraction (PXRD) 122 3.32 Optical Microscopic Examination 122 3.33 Scanning Electron Microscopy (SEM) 122 3.34 Analytical Methodology 123 3.34.1 Analytical Method for Estimation of Camptothecin analog in Formulations 3.34.2 Drug Content Estimation by HPLC 123 xii 116 123 3.34.2.1 Chromatographic Conditions 124 3.34.2.2 Standard Preparation 125 3.34.2.3 Sample Preparation 125 3.34.2.4 Preparation of System Suitability Solution 126 3.34.2.5 Calculations 126 3.34.3 Saturation Solubility of Drug Nanoparticles 127 3.35 Tablet Preparation 127 3.35.1 Selection of Tableting Excipients 127 3.35.2 Preparation of Tablets using Processed Camptothecin analog Granules 3.36 Evaluation of Blend Properties 128 3.36.1 Angle of Repose 128 127
3.36.2 Density 128 3.36.3 Carr s Index 129 3.36.4 Hausner Ratio 129 3.37 Evaluation of Tablet Physical Properties 130 3.37.1 Average Weight 130 3.37.2 Tablet Thickness 130 3.37.3 Tablet Hardness 130 3.37.4 Friability 130 3.37.5 Disintegration Time 130 3.37.6 Moisture content 131 3.37.7 Dissolution Studies 131 3.37.7.1 Apparatus 131 3.37.7.2 Dissolution Conditions 132 3.37.7.3 Calculations 132 3.38 In-Vivo Pharmacokinetic Study 133 3.38.1 Bioanalysis by HPLC 133 3.38.2 Chromatographic Conditions 134 3.38.3 Sample Preparation 135 3.39 Stability Evaluation 135 3.40 Results and Discussion 137 3.41 Solubility Studies 138 3.42 Preparation of Nanosuspension Using Wet Milling Apparatus 138 3.43 Stabilizer Screening for Production of Physically Stable Nanosuspensions 3.44 Scale-up of Nanosuspension Process using Media Mill 145 3.44.1 Effect of Process Time 146 3.45 Spray Drying Processes for Conversion of Nanosuspension into Solid Intermediate 3.46 Optical Microscopic Examination 150 xiii 139 148
3.47 Scanning Electron Microscopy (SEM) 151 3.48 Solid State Characterization 152 3.49 Solubility Studies of Un-milled, Micronized and Drug Nanoparticles 154 3.50 Preparation of Tablets 155 3.51 Physical Properties of Blend 156 3.52 Compression into Tablets 158 3.53 Dissolution Rate Evaluation 159 3.54 In-Vivo Evaluation 162 3.55 Stability Evaluation 163 CHAPTER-IV 4.0 Summary and Conclusions 165 4.1 Summary 166 4.2 Conclusion 168 CHAPTER-V 5.0 References 170 CHAPTER-VI 6.0 Appendix 180 6.1 List of Publications 193 6.2 List of Presentations 195 xiv