who invented microencapsulation

What is micro-encapsulation?

Micro-encapsulation. Microencapsulation is a process in which tiny particles or droplets are surrounded by a coating to give small capsules, of many useful properties. In general, it is used to incorporate food ingredients, enzymes, cells or other materials on a micro metric scale. Microencapsulation can also be used to enclose solids, liquids,...

What is the role of microencapsulation in fish oil?

Thus, microencapsulation has been used for incorporation of fish oil as the core material, hiding the unpleasant sensory characteristics of the oil [ 17 ]. In studies with omega-3 microcapsules applied in food products, Chavez-Servín et al. [ 84] examined the addition of microencapsulated omega-3 fatty acids in infant formulas.

What are microcapsules and artificial cells?

Microcapsules or artificial cells are prepared in such a way as to prevent their contents from leaking out and causing immunological reactions, but still allowing those contents to interact freely in biochemical reactions.

Is microencapsulation the best method of PCM integration?

Microencapsulation has shown to be the most promising method of encapsulation for integration of PCMs in building materials. However, microencapsulation leads to a lower latent heat storage capacity per unit volume and unit weight than the pure PCM due to the addition of the encapsulating material.

Where is microencapsulation used?

foodMicroencapsulation is the protective technology of encapsulating solid, liquid or gas materials into micro particles with a diameter of 1–1000 μm, and has been widely used in fields of medicine, cosmetics, food, textile and advanced materials (Campos et al., 2013; Dubey et al., 2009).

Which technique is used for microencapsulation?

Large number of techniques for microencapsulation include spray chilling, spray cooling, fluidized bed coating, liposome entrapment, extrusion, freeze drying, and coacervation.

What is the most common method of microencapsulation?

The spray drying technique is the most common microencapsulation method, has been used for decades to encapsulate mainly flavors, lipids, and pigments, but its use in thermo-sensitive products, such as microorganisms and essential oils, can be limited because the required high temperature causes volatilization and/or ...

How are microcapsules made?

Microencapsulation is a technique in which chemicals are released in a controlled manner over a long period. In this process small particles or droplets are confined in a coating to give small capsules or microcapsules. The materials inside the capsules form the core and the outside coating becomes a barrier wall.

What is the size range of microencapsulation?

between 50 nm to 2 mmThe term “microcapsule” is defined, as a spherical particle with the size varying between 50 nm to 2 mm containing a core substance.

What are the types of microcapsules?

Different types of microcapsules: (i) simple microcapsule, (ii) matrix (microsphere), (iii) irregular microcapsule, (iv) multicore microcapsule, (v) multiwall microcapsule, and (vi) assembly of microcapsule.

What are the advantages of microencapsulation?

One of the most important benefits of microencapsulation is improving the stability of nutrients, preventing ingredient interactions and degradation. The coating matrix effectively separates particles and prevents them from contacting each other.

What is core material in microencapsulation?

The core may be a crystal, a jagged adsorbent particle, an emulsion, a Pickering emulsion, a suspension of solids, or a suspension of smaller microcapsules. The microcapsule even may have multiple walls. IUPAC definition. Microcapsule: Hollow microparticle composed of a solid shell surrounding a.

What is the mechanism of encapsulation?

In cryptographic protocols, a key encapsulation mechanism (KEM) is used to secure symmetric key material for transmission using asymmetric (public-key) algorithms. It is commonly used in hybrid cryptosystems. In practice, public key systems are clumsy to use in transmitting long messages.

What is encapsulation science?

Encapsulation is the process of stabilization of active compounds through the structuring of systems capable of preserving their chemical, physical, and biological properties, as well as their release or delivery under established or desired conditions [1].

Why are drugs encapsulated?

Encapsulation is commonly adopted in drug delivery systems to form a shell to protect a particular drug, and prevent it from leaching out before reaching the targeted site. The shell is usually made of hydrogel matrices or polymeric nanostructures that are able to entrap the targeted drug.

What is microencapsulation PDF?

Microencapsulation is defined as a process of enclosing or enveloping solids, liquids or even gases within second material with a continuous coating of polymeric materials yielding microscopic particles (ranging from less than 1 micron to several hundred microns in size).

Which of the following does the technique of microencapsulation depend on?

The technique of microencapsulation depends on the physical and chemical properties of the material to be encapsulated.

Which technique used for coacervation microencapsulation technique?

9.3. Phase coacervation is one of the oldest and most widely used techniques of microencapsulation and can be divided into two groups: simple coacervation, which implies the use of one colloidal solute such as gelatine, chitosan, etc.

Which microencapsulation technique is the invention of Prof de Wurster?

The Air Suspension Coating ProcessThe Air Suspension Coating Process was invented by Professor Dale E. Wurster while at the Department of Pharmacy, University of Wisconsin.

Which one of the following is the core material used in microencapsulation?

MICROENCAPSULATION DRUG DELIVERY SYSTEM - AN OVERVIEWCore materialCharacteristic propertyFilm product formActivated charcoalAdsorbentDry powderLiquid crystalLiquidFlexible film for thermal mapping for anatomyPotassium chlorideHighly water soluble solidCapsuleAspirinSlightly water soluble solidTablet or capsule7 more rows•Jul 25, 2016

Why is microencapsulation used?

Microencapsulation can be used to slow the release of a drug into the body. This may permit one controlled release dose to substitute for several doses of non-encapsulated drug and also may decrease toxic side effects for some drugs by preventing high initial concentrations in the blood.

What is a microcapsule?

In its simplest form, a microcapsule is a small sphere comprising a near-uniform wall enclosing some material. The enclosed material in the microcapsule is referred to as the core, internal phase, or fill, whereas the wall is sometimes called a shell, coating, or membrane. Some materials like lipids and polymers, such as alginate, may be used as a mixture to trap the material of interest inside. Most microcapsules have pores with diameters between a few nanometers and a few micrometers. The coating materials generally used for coating are: 1 Ethyl cellulose 2 Polyvinyl alcohol 3 Gelatin 4 Sodium alginate

What is the deposition rate of cellulose fibers?

In one process, e.g. cellulose fibers are encapsulated in polyethylene while immersed in dry toluene. Usual deposition rates are about 0.5μm/min. Coating thickness ranges 0.2–75 μm (0.0079–2.9528 mils). The coating is uniform, even over sharp projections. Protein microcapsules are biocompatible and biodegradable, and the presence of the protein backbone renders the membrane more resistant and elastic than those obtained by interfacial polycondensation.

How does interfacial polycondensation work?

In interfacial polycondensation, the two reactants in a polycondensation meet at an interface and react rapidly. The basis of this method is the classical Schotten-Baumann reaction between an acid chloride and a compound containing an active hydrogen atom , such as an amine or alcohol, polyesters, polyurea, polyurethane. Under the right conditions, thin flexible walls form rapidly at the interface. A solution of the pesticide and a diacid chloride are emulsified in water and an aqueous solution containing an amine and a polyfunctional isocyanate is added. Base is present to neutralize the acid formed during the reaction. Condensed polymer walls form instantaneously at the interface of the emulsion droplets.

How does a microencapsulation wall break?

Capsule contents may be released by melting the wall, or dissolving it under particular conditions, as in the case of an enteric drug coating. In other systems, the wall is broken by solvent action, enzyme attack, chemical reaction, hydrolysis, or slow disintegration.

What is ionotropic gelation?

Ionotropic gelation occurs when units of uric acid in the chains of the polymer alginate, crosslink with multivalent cations. These may include, calcium, zinc, iron and aluminium.

What is the oldest process used in the pharmaceutical industry?

Pan coating. This process widely used in the pharma industry, is the oldest industrial procedure for forming small, coated particles or tablets. The particles are tumbled in a pan or other device.

When was microencapsulation first used?

Microencapsulation technology has been used commercially since the 1950s when it became established as the basis for carbonless copy paper and is now used widely within the food processing (Vilstrup, 2001 ), pharmaceutical ( Benita, 1996 ), agrochemical ( Knowles, 1998) and cosmetic industries ( Meyer, 2005 ). Similarly, the technology has played a significant role in new developments in the textile industry and has been used, for example, to impart a range of long-lasting finishes to textile materials, including fragrances, antimicrobials, insecticides, fire retardants and temperature-control phase-change materials ( Nelson, 1991, 2001; Marinkovic et al., 2006 ). Microencapsulation has also been the major force behind the rise of ‘cosmeto-textiles’ delivering moisturising agents, vitamins and anti-wrinkle/anti-ageing active ingredients onto the skin ( Cognis, 2007 ). A significant area for research and development within the textile sector has been the microencapsulation of dyes and pigments for a wide range of applications. Microencapsulated dyes and pigments are now well established, particularly within the textile printing sector and within the novelty apparel sector where a number of thermo-and photochromic finishes are available. More at the experimental stage is the development of micro-encapsulated dyes to improve traditional textile dyeing processes, much of the research being aimed at reducing the environmental impact of textile dyeing, particularly in reducing water usage and colour contamination of water courses.

What is microencapsulation technology?

Microencapsulation technology was developed for microbial cell immobilization starting in 1993 to overcome the drawbacks encountered with gel entrapment, such as limited cell loading due to the small void space of polymer matrix and cell leakage [73 ]. A microcapsule consists of a semi-permeable, spherical, thin, and strong polymer membrane surrounding a liquid core, with a diameter varying from a few microns to 1 mm [ 39]. Because of the absence of a solid or gelled core and small diameter, mass transfer limitation is reduced in microencapsulation.

Why is microencapsulation important?

Therefore, microencapsulation is very suitable for improving the stability of thermochromic mixtures. After being encapsulated, the thermal stability and the resistances to leaching, acid and solvent for thermochromic materials would be significantly enhanced, which obviously extends their application fields.

How is in situ polymerization done?

15.6 ). The first process is the formation of emulsion for liquid core or suspension for solid core. Then, reactive monomers (or soluble prepolymers) slowly precipitate on the core particles under the action of heat and catalysts. The chemical reaction for melamine-formaldehyde resin (a typical shell material for in situ polymerization) during microencapsulation is shown in Fig. 15.7, mainly including the hydroxymethylation between melamine and formaldehyde under alkaline condition and the condensation of prepolymers catalysed by acid and heat. The performance of microcapsules generally depends on synthetic technology of pre-polymer, concentration of shell material, core/shell ratio, emulsifying technology and curing condition.

When was microcapsule made?

The production of microcapsules began in 1930s and boomed in 1970s. According to the forming mechanism and condition of shell, microencapsulation methods can be divided into three categories, namely physical, chemical and physicochemical methods ( Jyothi et al., 2010) ( Table 15.5). As for physical method, the microencapsulation is based on ...

What is microencapsulation?

Microencapsulation is a process by which individual particles of an active agent can be stored within a shell, surrounded or coated with a continuous film of polymeric material to produce particles in the micrometre to millimetre range, for protection and/or later release.

What is the morphology of microcapsules?

The ultimate morphology of microcapsules mainly depends on the morphology of core materials. Generally, solid core remains its morphologies during microencapsulation, while microcapsules with liquid core are usually spherical resulting from the process of mechanical dispersion or emulsion. Table 15.5.

Abstract

A number of excellent reviews have been published on microencapsulation (I–XI). It is not the purpose of this paper to give a comprehensive review of the field, but rather to acquaint the listener with the historical background and give him a general appreciation of the capabilities and limitation; of the technology.

Keywords

These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

When was microencapsulation first used?

Microencapsulation technology has been used commercially since the 1950s when it became established as the basis for carbonless copy paper and is now used widely within the food processing (Vilstrup, 2001 ), pharmaceutical ( Benita, 1996 ), agrochemical ( Knowles, 1998) and cosmetic industries ( Meyer, 2005 ). Similarly, the technology has played a significant role in new developments in the textile industry and has been used, for example, to impart a range of long-lasting finishes to textile materials, including fragrances, antimicrobials, insecticides, fire retardants and temperature-control phase-change materials ( Nelson, 1991, 2001; Marinkovic et al., 2006 ). Microencapsulation has also been the major force behind the rise of ‘cosmeto-textiles’ delivering moisturising agents, vitamins and anti-wrinkle/anti-ageing active ingredients onto the skin ( Cognis, 2007 ). A significant area for research and development within the textile sector has been the microencapsulation of dyes and pigments for a wide range of applications. Microencapsulated dyes and pigments are now well established, particularly within the textile printing sector and within the novelty apparel sector where a number of thermo-and photochromic finishes are available. More at the experimental stage is the development of micro-encapsulated dyes to improve traditional textile dyeing processes, much of the research being aimed at reducing the environmental impact of textile dyeing, particularly in reducing water usage and colour contamination of water courses.

How is microencapsulation accomplished?

Microencapsulation in a fluidized bed is accomplished via formation of a fluidized bed of particles with spraying by a solution or suspension of a film-forming material.

How does powder microencapsulation work?

As film-forming material, the powder microencapsulation via vapor condensation uses a metal that is vaporized in a vacuum and con densed on the cold powder surface.

Why is microencapsulation important?

Therefore, microencapsulation is very suitable for improving the stability of thermochromic mixtures. After being encapsulated, the thermal stability and the resistances to leaching, acid and solvent for thermochromic materials would be significantly enhanced, which obviously extends their application fields.

How big is a microcapsule?

Microencapsulation is by far the most frequently used technology to micropackage cosmetic ingredients in textiles, where microcapsules typically have mean diameters of 1–10 μm, as compared to a range of 5–30 μm for a single textile fiber—from about 5 μm for microfibers to about 30 μm for coarse wool.

How is in situ polymerization done?

15.6 ). The first process is the formation of emulsion for liquid core or suspension for solid core. Then, reactive monomers (or soluble prepolymers) slowly precipitate on the core particles under the action of heat and catalysts. The chemical reaction for melamine-formaldehyde resin (a typical shell material for in situ polymerization) during microencapsulation is shown in Fig. 15.7, mainly including the hydroxymethylation between melamine and formaldehyde under alkaline condition and the condensation of prepolymers catalysed by acid and heat. The performance of microcapsules generally depends on synthetic technology of pre-polymer, concentration of shell material, core/shell ratio, emulsifying technology and curing condition.

When was microcapsule made?

The production of microcapsules began in 1930s and boomed in 1970s. According to the forming mechanism and condition of shell, microencapsulation methods can be divided into three categories, namely physical, chemical and physicochemical methods ( Jyothi et al., 2010) ( Table 15.5). As for physical method, the microencapsulation is based on ...

What is the oldest microencapsulation technique?

The oldest microencapsulation technique and one of the most widely used techniques is coacervation, which involves macromolecular aggregates that form a colloidal system with two existing phases: one that is rich in colloids (coacervate) and one that is poor in colloids (supernatant). This method is performed by depositing the encapsulating agent around the active compound through physicochemical changes, such as temperature, polarity, pH, or ionic strength [ 2, 6 ].

What is the purpose of microencapsulation?

The goals of microencapsulation are to coat an active compound (core) by an encapsulating agent, also known as wall material, which will isolate the active material, thereby protecting the active material from adverse changes or to hide sensory properties that are not appreciated by consumers . The isolation provided by the encapsulating material will break under the application of a specific stimulus (e.g., pH or heat), releasing the active substance in the specific target location or under ideal conditions [ 2 ].

What is microencapsulation in food?

Microencapsulation is a group of technologies aiming to produce small particles called microcapsules that can be released at a specific speed under certain conditions. Microencapsulation technology is used in the pharmaceutical, agrochemical, and food industries; however, microcapsule production is most challenging for applications in the food industry owing to the high costs of the technique, which may make the final product too expensive. Common methods for microencapsulation include spray-drying and coacervation, and different wall materials and filling materials can be used for both techniques. In this review, we summarize current methodologies used for microencapsulation, with a focus on applications in the food industry.

How is alginate used in cell immobilization?

Alginate can also be used to produce microcapsules and cell immobilization through ionotropic gelation, which involve s dropping the concentrated alginate solution into calcium chloride solution, externally gelling the polymer into a microcapsule. The size of the microcapsules formed using external gelation is governed by the size of droplets formed during the extrusion process [ 40] and ranges from tens of microns to millimeter size. Less commonly, microcapsules may be formed by internal gelation, in which the alginate in solution contains calcium carbonate [ 41 ].

Why are microcapsules so challenging?

The techniques for producing microcapsules are significantly more challenging in the food industry than in other industries because the sensory qualities of foods cannot be compromised by the addition of encapsulated components. Furthermore, food matrices are more complex than those used in pharmaceutical and cosmetic industries. Moreover, in the food industry, microcapsules must be ingested orally, resist the adverse conditions of the gastrointestinal tract, and exhibit mucoadhesive properties [ 1 ]. Several different methods for microcapsule production have been developed, and microcapsules can be fabricated using various materials, which are chosen depending on the function of the microcapsules [ 4 ].

Why is microencapsulation important?

Microencapsulation is used to reduce adverse aromas, volatility, and reactivity of food products and to provide food products with greater stability when exposed to adverse conditions (e.g., light, O 2, and pH) [ 5, 6 ]. Favaro-Trindade et al. [ 1] stated that microencapsulation is used in the food industry to reduce the reactivity of the active material in the external environment, reduce the speed of losses and evaporation of the core material into the medium, improve food handling, provide controlled release of the active product, mask unpleasant odor and taste, and allow the encapsulated material to be distributed in a food formulation homogeneously. However, microencapsulation is associated with dramatically increased costs of production, which may limit the economic viability of the method.

Why are proteins not used in microencapsulation?

Despite these studies, proteins from plant sources have not been commonly used as carrier or wall materials in microencapsulation applications owing to limitations related to heat instability and organic solvent sensitivity. However, the use of reticulating agents to convert the proteins into a more stable form may improve their industrial applicability [ 64 ].

What is microencapsulation in food?

Microencapsulation is a process in which active substances are coated by extremely small capsules the success of this technology is due to the correct choice of the wall material, the core release form and the encapsulation method some important microencapsulation aspects such as the capsule, wall material, core release forms, and encapsulation methods and their use in food technology. Microencapsulation is receiving considerable attention fundamentally, developmentally, commercially, etc. Key words: Controlled release, Cosmetics, Microcapsules, Microencapsulation, Microorganism

What is nanotechnology used for?

A comprehensive and authenticate From the ancient time nanotechnology is widely used for various treatment like cancer based treatment and presently ndds is used for treatment of psoriasis and it play good role in healthcare field nowadays one of the focused area in nanotechnology which is nanoparticles.nanoparticles are at the forefront of the rapidly developing field of nanotechnology with several potential applications in drug delivery, clinical medicine and research as well as in other varied sciences. Due to their unique size-dependent properties, nanoparticles offer the possibility to develop new therapeutics. The ability to incorporate drugs into nanocarriers offers a new prototype in drug delivery that could be used for secondary and tertiary levels of drug targeting. Different production methods which are suitable for large scale production and applications of nanoparticles are described. Appropriate analytical techniques for characterization of nanoparticles like photon correlation spectroscopy, scanning electron microscopy, differential scanning calorimetry are highlighted. The prefix nano comes from the ancient Greek vavoc through the latin names meaning very much. Nanoparticles are defined as particulate dispersion or solid particles with size range of 10-1000nm. The drug entrapped, dissolved, encapsulated or attached to nano-particles matrix surrounding interfacial layer.

Overview

Microencapsulation is a process in which tiny particles or droplets are surrounded by a coating to give small capsules, with useful properties. In general, it is used to incorporate food ingredients, enzymes, cells or other materials on a micro metric scale. Microencapsulation can also be used to enclose solids, liquids, or gases inside a micrometric wall made of hard or soft soluble film, in order to reduce dosing frequency and prevent the degradation of pharmaceuticals.

Reasons for encapsulation

Techniques of microcapsule manufacture

Release methods and patterns

Applications

See also

Bibliography

External links