ABSTRACT
Encapsulation or commonly referred to as microencapsulation involves the incorporation of actives (such as: avors, drugs, enzymes, cells, or other materials) in small capsules. Capsules offer a means to protect sensitive components, transform liquids into easily handled solid ingredients, and incorporate controlled release attributes (such as time-release, targeted-release, or trigger-release mechanisms) into the product formulations. Various techniques are available to design capsules depending on the end use of the nal product. A timely and targeted release improves the effectiveness of actives, broadens the application range of ingredients, and ensures optimal dosage, thereby
1.1 Denitions.................................................................................................................................4 1.2Justication for Encapsulation ..................................................................................................4 1.3 Classication .............................................................................................................................5 1.4Techniques of Microencapsulation ...........................................................................................6 1.5 Criteria for Selecting Encapsulation Technology .....................................................................6 1.6 Annular Jet (Vibrational Nozzle) ..............................................................................................7 1.7Centrifugal Extrusion ...............................................................................................................8 1.8 Centrifugal Suspension Separation ...........................................................................................8 1.9 Cocrystallization .......................................................................................................................9 1.10 Coacervation .............................................................................................................................9 1.11 Emulsication/Emulsion Polymerization .................................................................................9 1.12Fluid-Bed Coating .................................................................................................................. 10 1.13 Interfacial Polymerization ...................................................................................................... 10 1.14Inclusion Complexation .......................................................................................................... 10 1.15 Ionic Gelation (Hydrogel Microspheres) ................................................................................ 11 1.16 Liposomes ............................................................................................................................... 11 1.17 Lyophilization ......................................................................................................................... 11 1.18 Melt Extrusion (Melt Injection) .............................................................................................. 12 1.19Pan Coating ............................................................................................................................. 12 1.20 Phase Separation ..................................................................................................................... 12 1.21 Spray Drying ........................................................................................................................... 12 1.22Spray Congealing.................................................................................................................... 13 1.23Spinning Disk (Centrifugal Suspension Separation).............................................................. 13 1.24Solvent Evaporation ................................................................................................................ 13 1.25Supercritical Fluid Assisted Encapsulation ............................................................................ 13 1.26 Controlled Release .................................................................................................................. 14 1.27Release Mechanisms ............................................................................................................... 14 1.28 Release Rates .......................................................................................................................... 14 1.29 Conclusions ............................................................................................................................. 15 References ........................................................................................................................................ 15
improving the cost effectiveness for the manufacturer. Encapsulation techniques can facilitate product development through the use of carefully tuned controlled release attributes.
