Microcapsules containing

Chen, H Wu, J.-C. and Chen, H.-Y. (1995) Preparation of ethylcellulose microcapsules containing theophylline by using emulsion non-solvent addition method. Journal of Microencapsulation, 12, 137-147. 

These two seemingly dissimilar applications have a common basis—both are examples of the pressure-sensitive release of a chemical. How are these products designed Tiny spherical capsules (microcapsules or microspheres) with a glass or polymer shell are filled with a liquid core and glued onto paper. For a scratch-and-sniff ad, the core of the microcapsules contains a liquid with the desired scent for carbonless paper, a liquid ink or dye is encapsulated within the... 

The transport of disulfoton from water to air can occur due to volatilization. Compounds with a Henry s law constant (H) of <10 atm-m /mol volatilize slowly from water (Thomas 1990). Therefore, disulfoton, with an H value of 2.17x10" atm-m /mol (Domine et al. 1992), will volatilize slowly from water. The rate of volatilization increases as the water temperature and ambient air flow rate increases and decreases as the rate of adsorption on sediment and suspended solids increases (Dragan and Carpov 1987). The estimated gas- exchange half-life for disulfoton volatilization from the Rhine River at an average depth of 5 meters at 11 °C was 900 days (Wanner et al. ] 989). The estimated volatilization half-life of an aqueous suspension of microcapsules containing disulfoton at 20 °C with still air was >90 days (Dragan and Carpov 1987). 

Chang TMS. In-vivo effects of semipermeable microcapsules containing L-asparaginase on 6C3HED lymphosarcoma. Nature 1971a 229 117-118. 

Stein EW, Volodkin DV, McShane Ml, Sukhomkov GB. Real-time assessment of spatial and temporal coupled catalysis within polyelectrolyte microcapsules containing coimmobilized glucose oxidase and peroxidase. Biomacromolecules 2006 7 710-719. 

Uchida, T., Kawata, M., and Goto, Si,vivo evaluation of ethyl cellulose microcapsules containing ampicillin using rabbits, beagle dogs and humalnfjharmacobiodyn., 9, 631, 1986. 

Uchida, T., et al. 1987. Preparation and evaluation of ethyl cellulose microcapsule containing cefadroxil or cephradine. Yakuzaigaku 47 254. 

Chinnayelka S, McShane MJ. Glucose sensors based on microcapsules containing an orange/red competitive binding resonance energy transfer assay. Diabetes Technology Therapeutics 2006, 8, 269-278. 

Kondo, K., Otono, T. and Matsumoto, M. (2004) Preparation of microcapsules containing extractants and the application of the microcapsules to the extractive fermentation of lactic acid. Journal of Chemical Engineering of Japan, 37, 1. 

In pressure-sensitive printing technology the color former is dissolved in a solvent and encapsulated.44 The use of pressure (pen, typewriter key) ruptures microcapsules containing the color former, which generates color upon... 

The first plot received 500 g.a.i./h of displarlure as NCR gelatin-walled microcapsules containing 2% ai. The formulation, applied as an aqueous suspension, also contained 1 of sticker to aid adhesion of the formulation to foliage. The second plot received 500 g./h. as Herculite Corporation sprayable laminate flakes containing 9.1 ai. The flakes consisted of two layers of vinyl, each 0.08 mm thick on both sides of a central porous layer containing the disparlure the surface area of the flakes was between 7 and 35 mm2 per side. The same sticker as that in the microcapsules was used. The third plot received 330 g.a.i./h as "Conrel" controlled release hollow fibers containing nominally 11.5% ai. a suitable sticker was also incorporated in the formulation. (Note that the use of trade or proprietary names here or elsewhere does not constitute an endorsement by the USDA). 

The University of Illinois developed a technology for repairing hairline cracks in RPs by embedding microcapsules containing monomers corresponding to the plastic matrix.403 404... 

Makino et al. [63] measured the electrophoretic mobility of four types M1-M4 of hydrophilic gel microcapsules containing water prepared by an interfacial polymerization method. Each type of microcapsules has membranes of different compositions. The results of the analysis of the measured mobilitiy values on the basis of Eqs. (21.128) are given in Figs 21.10 and 21.11. 

The self-healing system is based on microcapsules containing liquid dicyclopentadiene... 

Lee SJ and Rosenberg M. Preparation and properties of glutaraldehyde cross-hnked whey protein-based microcapsules containing theophylline. J. Control. Rel. 1999 61 123-136. 

Chen, H. Wu, J.C. Chen, H.Y. Preparation of ethyl cellulose microcapsules containing teophylline by using emulsion non-solvent addition method. J. Microencapsulation 1995, 12 (2), 137-147. 

El-Gibaly I, Anwar MM. Development, characterization and in vivo evaluation of polyelectrolyte complex membrane gel microcapsules containing melatonin-resin complex for oral use. Bull Pharm Sci Assiut XJniv 1998 21(2) 117-139. 

Encapsulation. Immobilization of enzymes by encapsulation within semipermeable structures dates back to the 1970s. There are three fundamental variations of this approach. In coacervation, aqueous microdroplets containing the enzyme are suspended in a water-immiscible solvent containing a polymer, such as cellulose nitrate, polyvinylacetate, or polyethylene. A solid film of polymer can be induced to form at the interface between the two phases, thereby producing a microcapsule containing the enzyme. A second approach involves interfacial polymerization in which an aqueous solution of the enzyme and a monomer are dispersed in an immiscible solvent with the aid of a surfactant. A second (hydrophobic) monomer is then added to the solvent and condensation polymerization is allowed to proceed. This approach has been used extensively with nylons, but is also applicable to polyurethanes, other polyesters, and polyureas. 

Mishima K, Matsuyama K, Furukawa A, Fuji T, Shida J, Nojiri N, Kubo H, Katada N. Control of polymer coating thickness of microcapsules containing inorganic microparticles using cosolvency of supercritical carbon dioxide. Ka-gaku Kogaku Ronbunshu 2001 27 700-706. 

Benoit JP, Richad J, Thies C. Preparation of microcapsules containing active substances coated with a polymer. France, WO 9813136, 1998. 

Figure 8, Baboon peripheral serum levels of immune-reactive norethisterone after intramuscular infection of 300 mg of poly(DL-lactic acid) microcapsules containing 75 mg of drug. Size of capsules A, 10-240 ijjn B, 65-124 ym C, 10-40 yjn, (Reprinted with permission from Ref. 36, p, 75, Copyright 1980.)...

Fig. 1.6 SEM micrograph of PLG-microcapsules containing human serum albumin (left) and cytochrome C (right) as model drug.

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