Encapsulation/controlled release

Lipid micellization Vesicles for encapsulation, controlled release, functional incorporation of proteins and mimicking of biological membranes Singh et al., 1995 Taylor et al., 2005 Sagalowicz et al., 2006 Mozafari et al., 2006... 

Johnson, R.M. and A.B. Pepperman (1995a). Soil column mobility of metribuzin from alginate-encapsulated controlled release formulations. J. Agric. Food Chem., 43 241-246. 

Encapsulated controlled-release Fewer erosions as compared to... 

Meat Products. Citric acid is used in cured meat products to increase the effectiveness of the antioxidant preservatives, as a processing aid, and a texture modifier. It is often encapsulated and released at a specific temperature from a controlled release matrix. 

Cyclopentadiene oligomers have been formed by vapor deposition of CPD on kaolin to afford a sorbant for removal of oil from water (71). They are also employed as coatings for controlling release rates of fertilizers (72). Thermal addition of sulfur to a mixture of DCPD and CPD oligomers has led to a number of beneficial appHcations such as waste water oil adsorbant powdery foams (73), plasticized backing for carpets and artificial turfs (74), and in modified sulfur cements for encapsulating low-level radioactive wastes (75). 

The main purpose of pesticide formulation is to manufacture a product that has optimum biological efficiency, is convenient to use, and minimizes environmental impacts. The active ingredients are mixed with solvents, adjuvants (boosters), and fillers as necessary to achieve the desired formulation. The types of formulations include wettable powders, soluble concentrates, emulsion concentrates, oil-in-water emulsions, suspension concentrates, suspoemulsions, water-dispersible granules, dry granules, and controlled release, in which the active ingredient is released into the environment from a polymeric carrier, binder, absorbent, or encapsulant at a slow and effective rate. The formulation steps may generate air emissions, liquid effluents, and solid wastes. 

Microcapsules can be used for mammalian cell culture and the controlled release of drugs, vaccines, antibiotics and hormones. To prevent the loss of encapsulated materials, the microcapsules should be coated with another polymer that forms a membrane at the bead surface. The most well-known system is the encapsulation of the alginate beads with poly-L-lysine. 

Insulin (molecular weight 7000) has been formulated in controlled release microbeads and pellets (135,136). A solvent evaporation micro-encapsulation procedure was used to produce microspheres with up to 20% by weight insulin. Solvent-casting techniques were used to prepare pellets. The investigations demonstrated that the PLA... 

An important class of materials that originates from the precursor core-shell particles is hollow capsules. Hollow capsules (or shells ) can be routinely produced upon removal of the core material using chemical and physical methods. Much of the research conducted in the production of uniform-size hollow capsules arises from their scientific and technological interest. Hollow capsules are widely utilized for the encapsulation and controlled release of various substances (e.g., drugs, cosmetics, dyes, and inks), in catalysis and acoustic insulation, in the development of piezoelectric transducers and low-dielectric-constant materials, and for the manufacture of advanced materials [14],... 

King, A.K., Encapsulation of food ingredients a review of available technology, focusing on hydrocolloids, in Encapsulation and Controlled Release of Food Ingredients, Risch, S.J. and Reineccius, G.A., Eds., American Chemical Society, Washington, 1995, 26. 

Zentner and coworkers [24,26] utilized this information in their development of a system that releases this drug over a 24 hr period. The use of NaCl to modulate the release of diltiazem presents an interesting problem in that the concentration of the solubility modifier must be maintained within certain limits and below its saturation solubility within the device. To solve this problem, core formulations were developed that contained both free and encapsulated NaCl. The encapsulated NaCl was prepared by placing a microporous coating of cellulose acetate butyrate containing 20 wt% sorbitol onto sieved NaCl crystals. The coated granules released NaCl over 12-14 hr period via an osmotic mechanism into either water or the core tablet formulation. The in vitro release profile for tablets (core I devices) containing 360 mg of diltiazem HC1 and 100 mg of NaCl equally divided between the immediate release and controlled release fractions... 

Halloysite was found to be a viable and inexpensive nanoscale container for the encapsulation of biologically active molecules and drugs as was first demonstrated by Price et al. [5-8]. Its physicochemical characterization as a novel drug delivery system was also reported by Levis and Deasy et al. [9,10], who further demonstrated the controlled release of diltiazem hydrochloride and propanol hydrochloride... 

The encapsulation and release of l,3-bis(2-chloroethyl)nitrosourea (BCNU) in P(CPP-SA) 20 80 wafers was the first implantable controlled release device based on polyanhydrides that was FDA-approved and marketed (Gliadel ) (Chasin et al., 1988). BCNU was encapsulated by two techniques, trituration and co-dissolution, resulting in different release profiles (Chasin et al., 1990, 1991). The triturated samples released faster than those prepared by co-dissolution, presumably due to more homogeneous loading in the samples prepared by co-dissolution. 

Initially, the sol gel compositions were optimized using Congo red dye as the dopant because of its optical properties. This facilitates monitoring of the release process by optical spectroscopy. Next, the gels were evaluated for their stabilization and release of subtilisin. These sol gel matrices bring about controlled release of the encapsulated enzyme molecules as a response to a change in the water content of the medium (Figure 2.20).15... 

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