Microencapsulation, defined as a process (integrate micro-particles) which involves the complete envelopment of a material(s) within a porous/impermeable membrane has already provided users with a myriad of applications. These particles have enabled the generation of innovative products in areas such as food, agricultural, textiles, cosmetics and the pharmaceutical sector1, as well as helping scientists to develop new treatments against diseases2.
There are numerous reasons for encapsulation a product within a membrane and are summarized in Fig. 1. The most common is the protection of a product from a harmful environment(s)1. Examples include the encapsulation of animal and stem cells for generating artificial implants3,4 or enabling the obtainment of high density cell cultures to produce larger quantities of medically important drugs1. In these cases the encapsulation process protects the cells against immune response in the body and shear stress in the bioreactor.[Page Break]
The food industry has been by far the biggest benefactor of the technology. A strategic business report published in 2010 estimates the technology will generate nearly $40 billion in revenue for the food industry by 20155. Here microcapsules are used to prevent unfavourable reactions with other ingredients, control organoleptic properties, and prevent degradation of expensive bioactive ingredients during processing and packaging1. The latter has enabled food manufacturers to add significant value to their products and obtain considerably higher mark-ups.
Microencapsulation has also been employed for sustained, controlled or targeted release of encapsulated products, and has found substantial usage for the delivery of numerous materials such as pharmaceuticals, bioactive ingredients, fragrances, adhesives, vitamins and flavours1.[Page Break]
Recently the technology has being applied to new fields, which includes environmental applications for the recovery of pollutants from water6, in fermentations to help purify bio-products7 and chemical processes to optimise reactions. The technology has also being adopted for technical applications, whereby it has being employed to improve flow and handling (including safety) properties of solids and liquids1.
Successful application of microencapsulation to such a variety of process requires a production technique which must adhere to stringent criteria, especially for medical and biotechnological applications1. One such technique, commonly referred to as vibrating-nozzle procedure, is available and can be performed on the vibration technology Encapsulator produced by BUCHI Labortechnik AG. This production technique has gained significant interest from manufacturers and scientific researchers on account of its ability to produce small, mono-dispersed, homogenous microcapsules and particles with a narrow size distribution. In addition it is easy to set up and operate, has low operating costs and can be integrated into a GMP process. For these reasons it is one of the most commonly employed techniques to produce microcapsules at lab-scale1.[Page Break]
The most important criteria for any microcapsule production technique is the ability to scale-up the process to produce higher quantities of particles, without incurring a significant change in capsule properties. The new Buchi multi-nozzle Encapsulator that has six separate nozzles achieves such a goal, and further increases in production volumes can be simply achieved by adding more nozzles1.
The simplistic nature of the Buchi Encapsulator should further improve and expand applications of the technology in many fields, which to-date hasn't been possible due to the unavailability of suitable production techniques to produce the required microcapsules. This should lead to the establishment of new products, improvement of existing ones, or in some cases completely redefine the role of a commodity. In addition as expressed by many international experts in medicine and biotechnology, further developments in microencapsulation also has the potential to help scientists to make breakthroughs in treating many diseases.
Enter √ at www.scientistlive.com/eurolab
Philipp John is Product Group Manager Spray Drying, BÜCHI Labortechnik AG, Flawil, Switzerland. www.buchi.com
References:
1. Whelehan et al, J Microencapsulation, 28, 669-688 (2011);2. Strand et al, Fundamentals of Cell Immobilisation Biotechnology, Kluwer Academic Publishers, Dordrecht (2004); 3. Park et al, Polym Adv Technol; 9: 734-739 (1998); 4. Visted et al, Neuro-Oncology; 3: 201-210 (2001); 5. San Jose. A Global Strategic Business Report. Global Industry Analysts Inc. (2010); 6. Whelehan et al, Water Res, 44, 2314-2324 (2010); 7. Whelehan et al, Biotechnol. Prog., 27, 1068-1077 (2011).
