Microencapsulated products

Several parenteral microencapsulated products have been commercialized the cote materials ate polypeptides with hormonal activity. Poly(lactide— glycohde) copolymers ate the sheU materials used. The capsules ate produced by solvent evaporation, polymer-polymer phase separation, or spray-dry encapsulation processes. They release their cote material over a 30 day period in vivo, although not at a constant rate. 

Aseptic processing is particularly useful with microencapsulated products, which almost always involve solutions of the polymer in organic solvents. Occasionally, bioactive molecules sensitive to... 

Spray drying. Microencapsulation by spray drying is an ideal method for poorly water-soluble drugs. The drug is dispersed in polymer (coating) solution, and then this dispersion is atomized into an airstream. The air, usually heated, supplies the latent heat of vaporization required to remove the solvent and forms the microencapsulated product. This technique is employed most commonly when microcapsules are intended for oral use because the resulting microspheres are porous in nature, and large batch sizes are required.89... 

Microencapsulation technology has been used from 1930s in packaging flavors and vitamins. Since the first commercial product was introduced for the carbonless copying paper, the technology has advanced to a new level. Various microencapsulation techniques are available nowadays, and the microencapsulated products are widely used in pharmaceutical, biomedical, agricultural, food, consumer products, and cosmetic industries. Representative applications of microparticles in the pharmaceutical and biomedical industries include ... 

A number of pharmaceutical microencapsulated products are currently on the market, such as aspirin, theophylline and its derivatives, vitamins, pancrelipase, antihypertensives, potassium chloride, progesterone, and contraceptive hormone combinations. ° ... 

Applications of microencapsulation in other industries are numerous. The best known microencapsulated products are carbonless copying paper, photosensitive paper, microencapsulated fragrances, such as scent-strips (also known as snap-n-burst ), and microencapsulated aromas ( scratch-n-sniff ). All of these products are usually prepared by gelatin-acacia complex coacer-vation. Scratch-n-sniff has been used in children s books and food and cosmetic aroma advertising. Microcapsules are also extensively used as diagnostics, for example, temperature-sensitive microcapsules for thermographic detection of tumors. ... 

Microencapsulated products have no bitter smell or aftertaste and have much better Gl tolerance. Regimens should be made as simple as possible to follow. 

The choice of the coating material (capsule) often depends on the purpose, or the purposes, of microencapsulation. Not all membranes are able to confer specific properties onto the microencapsulated product. The choice of the right coating is often crucial in achieving the microencapsulation purpose. Some one hundred suitable substances have been described (and already used) to form a microcapsule film. The most commonly used substances are collected in Table 8.1. 

Many processes for making microencapsulated product have been reported in the literature. They encompass a broad range of scientific and engineering disciplines. Some are used in high volume applications as in carbonless copy paper, others are in low volume specialty applications many are used in pilot plant scale. 

To overcome these deficiencies, different enrichment products and procedures were developed using selected microalgae, yeasts, (heterotrophi-cally grown) bacteria, microencapsulated products, emulsified products and self-emulsifying concentrates or microparticulate products or combinations thereof. Enrichment techniques make use of the fact that meta-nauplii of Artemia are non-selective filter-feeders which take up practically all particles, as long as they are of an adequate dimension. Figure 5.2 shows an enriched Artemia meta-nauplius in which you can clearly see the small oil... 

The introduction of encapsulation of volatiles, which 15 years ago saw very few publications, has now, by 2013, turned into a very active eld of applied research. Encapsulation or prolonged delivery of volatiles gives us more predictable and long-lasting effect of the compounds. The areas of application are very varied, and the industry using essential oils and terpenes foresees many prospects for new microencapsulated products. 

Since the introduction of the encapsulation of volatiles (essential oils/lower terpenes), the number of applications has multiplied. Encapsulation of volatiles gives us a more predictable and long-lasting effect of the products. The areas of applications are large and the industry of essential oils and terpenes foresee many prospects for microencapsulated products. 

Fish oils are an ideal way of emiching food products with long-chain n-3 fatty acids since they contain a high percentage of DHA and EPA. However, the highly unsaturated fish oils are notoriously unstable and oxidize spontaneously if not protected. This oxidation is the major cause of rancidity in foods to which fish oils have been added, either directly or in a protected form such as a microencapsulated product. 

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