Emulsions and Nanosuspensions

Transcription

1 Emulsions and Nanosuspensions for the Formulation of Poorly Soluble Drugs edited by Prof. Dr. rer. nat. Rainer H. MuUer Department of Pharmaceutics, Biopharmaceutics and Biotechnology Free University of Berlin Prof. Dr. rer. nat. Simon Benita School of Pharmacy The Hebrew University of Jerusalem Bernhard H. L. Bdhm Department of Pharmaceutics, Biopharmaceutics and Biotechnology Free University of Berlin The book chapters are based on the invited lectures and communications presented at the Colloidal Drug Carriers - cdc - 3rd Expert Meeting Berlin (Germany) May 1997 (main organizers: Prof. Dr. R. H. Miiller, Dr. W. Mehnert) 188 Figures and 34 Tables Scientific Publishers Stuttgart 1998

2 Preface 1 INTRODUCTION 13 1 Poorly soluble Drugs, a Challenge in Drug Delivery 15 Prof. Dr. P. P. Speiser, ETH-Ziirich 1.1 Notion Pharmaceutical concepts Liquid colloidal solutions \ Solid dispersions Solvent evaporation Solvent deposition Solid matrix incorporation Drug interactions Adsorption and Inclusion Stabilization Pharmacotechniques Overview Solvatation Micronization Instant evaporation Drug deposition Solid solutions Complexation Solid minicarriers Liquid minicarriers Short description of some pharmacotechniques Solubilization Micronization Precipitation Melting and instant cooling 21

3 Injection moulding Spraying Lyophilization Complexes Solid minicarriers Vesicular minicarriers Summary References 27 EMULSIONS 29 2 Emulsions as drug carriers - possibilities, limitations and future perspectives 31 Shmuel H. Klang, Marina Parnas and Simon Benita, Department of Pharmaceutics, School of Pharmacy, The Hebrew University of Jerusalem 2.1 Introduction Possibilities Emulsions intended for parenteral administration Current status of marketed emulsions Emulsions under current clinical evaluation Medicated emulsions under preclinical evaluation Non-parenteral emulsion formulations Topical Delivery Oral delivery Ocular Delivery Limitations Perspectives Long-circulating emulsions Positively-charged submicron emulsions References 60 3 Multiple Emulsions in Cosmetics 67 J. Nielsen, S.H. Gohla, Beiersdorf AG, Hamburg 3.1 Introduction History Manufacturing methods and current technologies 69

4 3.3.1 Two step technology One step technology Gel network derived droplet formation Direct emulsification (,,Oleosome" formation) Formation of intermediate multiple droplets during phase-inversion Partial-Phase Solu-Inversion Technology (PPS1T): Stability control and characterization of multiple emulsions Cosmetic Applications Summary Literature 78 4 Emulsions in food products: preparation, stabilization and applications 79 Willem van Nieuwenhuyzen, Eridania Beghin-Say Research & Development Centre, Central Soya/Stern Lecithin, Vilvoorde, Belgium 4.1 Introduction Basics of food production Food emulsifiers Lecithin Production of lecithins 84 AA Preparation and formulation of food emulsions Principles of food emulsion stability Effect of phospholipids Phospholipids in nanoemulsions Applications Margarine / Low fat spreads Mayonnaise / Dressings Dairy instant products Chocolate Flavor / Antioxidant encapsulation Conclusion Literature 99 5 Drug release and interfacial structure in emulsions 101 C. Washington, Department of Pharmaceutical Sciences, University of Nottingham 5.1 Introduction Measurement of drug release 103

5 5.3 Small-angle neutron scattering from emulsions Data analysis Effect of electrolytes Effect of temperature Conclusions Acknowledgements References Distribution and Metabolism of Emulsions In Vivo 119 M. Adolph, Krankenhauszweckverband, Institut fur Anasthesiologie und operative Sportmedizin, Augsburg, Germany 6.1 Metabolism of triglyceride-rich particles Metabolism of phospholipid-rich particles Lipid emulsions and reticuloendothelial system function Hepatic complications during long-term parenteral nutrition Lipid emulsions and cellular immunity Peroxidation in parenteral nutrition Lipid emulsions and drug delivery Conclusion References Safety and tolerability of intravenously administered phospholipids and emulsions 131 Michael J. Parnham, Pharmacological Institute for the Natural Sciences, Frankfurt 7.1 -Introduction Safety of parenteral phospholipids Interactions of phospholipids with transported drug Safety of emulsions Tolerability of mixed micelles Reduction ofdrugtoxicity by formulation in lipid emulsions Special patient consideration Conclusions References 138

6 NANOSUSPENSIONS Dissolution properties of poorly soluble drugs: Theoretical background and possibilities to improve the dissolution behaviour 143 Christer Nystrom, Department of Pharmaceutics, Uppsala University, Sweden 8.1 Introduction Dissolution theory and enhancement of dissolution rate Increase in solubility Decrease in effective diffusional distance Increase in effective dissolution surface area Formulations for instant dissolution of practically insoluble drugs Ordered mixtures Solid dispersions Conclusions References Nanosuspensions 149 Rainer H. Miiller, Bernhard H.L. Bohm, Institute of Pharmaceutical Technology, Free University of Berlin 9.1 Introduction Production of nanosuspensions Properties of nanosuspensions Size and width of size distribution of bulk population Content of microparticles in nanosuspensions Saturation solubility Dissolution velocity Electron microscopy of nanosuspensions Structure of nanosuspensions Physical stability of aqueous nanosuspensions Lyophilization Spray drying of nanosuspensions Large scale production of nanosuspensions Regulatory aspects 170 k 9.6 Nanosuspensions versus other highly dispersed systems 171

7 9.7 Perspectives References '. 173 DISPERSION TECHNIQUES The theory of high-pressure homogenization 177 Dipl.-Ing. S. Jahnke, APV Homogeniser GmbH, Liibeck 10.1 The Principle of High-pressure Homogenization The How Conditions in the Homogenizing Valve Pressure Reduction through Friction in the Homogenizing Valve Gap Frictional Pressure Loss Total Pressure Loss in the Homogenizing Valve Description of the Pressure Course in the Homogenizing Valve Gap Specific Amount of Energy and Temperature Load Mechanisms causing the Comminution in the Homogenizing Valve Comminution in the Laminar Shear Field Comminution in the Turbulent Shear Field Cavitation Influence of Important Product and Process Parameters Viscosity of the Disperse Phase Concentration of emulsifier agent Emulsifier Surface Occupation Kinetics and Oil Concentration Particle Size of Premix Homogenizing Pressure and Number of Passes Influence of the Homogenizing Temperature Homogenizers in Practical Use Division, capacity ranges Requirements for High-pressure Homogenizers for the Practical Use in Pharmaceutical Plants Factors influencing the Selection of Homogenizing Valves Summary, Literature 200

8 11 Manufacture of emulsions by means of high-pressure homogenization: Influence of homogenization parameters, oils and surfactants 201 Thomas Bock, Peter Kleinebudde and Bernd W. Miiller, Boehringer Ingelheim Pharma KG, Biberach, Germany Christian Albrechts Universitat, Kiel, Germany 11.1 Study design Emulsions containing 20% soya oil and 1.5% Lipoid S Effect of homogenization parameters on D50 values Effect of homogenization parameters on D99 values Effect of homogenization parameters on PCS radii Summary of results Emulsions containing 10% soya oil and 1.5% Lipoid S Emulsions containing 10% soya oil and 0.75% Lipoid S Comparison of results obtained with emulsions Selection of homogenization conditions Homogenization at 400 bar / 26 C Homogenization at 800 bar / 26 C Homogenization at 400 bar / 46 C Homogenization at 800 bar/46 C Comparison of emulsions manufactured at optimal temperatures and pressures Summary of results Row diagram for optimising the manufacture of emulsions References Optical Reflectance Measurement (ORM) - A novel approach for particle size measurement on highly concentrated dispersions 237 Rudolf Daniels, Roland Karwoth, Department of Pharmaceutical Technology, TU Braunschweig, Germany MeBtechnik Schwartz GmbH, Diisseldorf, Germany 12.1 Introduction : Principle of operation Data processing Range of particle sizes and resolution Experimental aspects 246

9 Sampling considerations Calibration Reproducibility Influence of measuring time and stirring speed Applications Particle size measurement on highly concentrated o/w emulsions Influence of formulation variables on the size distribution of o/w emulsions Conclusions References Large-scale production of liposomes by continuous high pressure extrusion 257 A. Sachse, Schering AG, Berlin 13.1 Introduction Extrusion of liposome suspensions Continuous high pressure extrusion Conclusions References High-Pressure Homogenization Techniques for the Production of Liposome Dispersions: Potential and Limitations 267 Martin Brandl, Pharmaceutical Technology, Institute of Pharmacy of the Albert-Ludwigs- University Freiburg, Germany 14.T Introduction Liposome Characteristics and Potential Applications Survey on Liposome Preparation Techniques Liposome Preparation by High-Pressure Homogenization Homogenizers Ways of Using Homogenizers For Liposome Preparation Controlling Liposome Size and Lamellarity Reasons for Controlling Liposome Size and Lamellarity What is the Real Size of Homogenized Liposomes Influence of Process Variables Pretreatment, Homogenization Pressure, Number of Cycles, i Valve Geometry and Temperature 275

10 Influence of Product Variables Lipid composition and Concentration Secondary Particle Growth Loading of Liposomes Encapsulation of Hydrophilic Materials Incorporation of Amphiphilic and Lipophilic Materials Calorimetric (DSC) Method for Monitoring Homogeneous Integration of Substances into the Bilayer Unwanted Effects Degradation of Materials Erosion of the Homogenizers Problems with High Lipid Concentrations, Dead Space and Lipid Loss Shelf Stability Conclusions and Prospects Summary of Product Characteristics and Process Variables Pros and Cons Using High-Pressure Homogenizers for Liposome Production Potential and Limitations Outlooks Acknowledgements References Abbreviations 294 SHORT COMMUNICATIONS ON DELIVERY SYSTEMS Emulsions 297 In Vivo Evaluation of Submicron Emulsions formulated with Pilocarpine 298 Correlation of statistical optimization 301 Production and stability of lipid parenteral emulsions 304 Thin-Film-FT-IR-Spectroscopy of Lecithin-Stabilized O/W-Emulsions 307 Characterization of a Soya-Oil-Emulsion with AFFF Lipid delivery systems 315 Preparation and Characterization of Colloidal 316 An X-Ray Study on Colloidal Monoglyceride-Water Dispersions 318 Multiple Melting Behavior of Lipid Nanoparticles 320 Effect of the Physical State of Lipid Nanoparticles on Incorporated Drugs 322 Mechanism of the Gel Formation 324

11 12 Colloidal Drug Dispersions as an Alternative Delivery System 326 Solid lipid nanoparticles (SLN) in aqueous dispersions 328 Production of solid lipid nanoparticles 330 In Vitro Degradation Assay for Solid Lipid Nanoparticles 334 Structure Investigations of Aciclovir Solid Lipid Nanoparticles 338 Drug Localization in Solid Lipid Nanoparticles Liposomal formulations 345 Highly concentrated semisolid phospholipid dispersions 346 Binding of positively charged liposomes to bacteria 350 Interaction between DNA, Nucleic Acid Stains and Differently Charged Lipids 353 Conditioning effect of lecithin dispersions versus liposomes on hair Nanosuspensions 359 High Pressure Homogenization as a Novel Technique for the Production Various delivery systems including production techniques 363 Evaluation ofph-sensitive nanoparticles for oral delivery 364 Incorporation of oligonucleotides in poly(d, L-lactic acid) nanoparticles 367 Studies on Pheniraminemaleate Micropellets 370 High Pressure Equipment for Preparation of Nanoparticles Interaction between particulate systems and body proteins 377 Two-dimensional electrophoresis and N-terminal microsequencing 378 Ex Vivo Investigations into the Opsonization of Iron Oxide 382 Analysis of plasma protein adsorption on commercial emulsions 385 INDEX 391