Spray drying microencapsulation

Other methodologies may be employed for specific drug products. For microencapsulated, spray-dried, and spray-freeze-dried formulations, an assessment of the particle size may be critical. Lyophilized, spray-dried, and spray-freeze-dried formulations must be... 

A variety of methods have been reported for producing microspheres including phase separation by polymer/polymer incompatibility and coacerva-tion [81] solvent evaporation or solvent removal [82] hot-melt microencapsulation spray drying interfacial polymerization and supercritical fluidprocessing teehniques (such as the gas antisolvent spray precipitation process [83] or rapid expansion of supercritical fluids [84]). The characteristics of the most important of these methods have been reviewed [85, 86]. 

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. 

In addition, Montenegro et al., (2007) determined that the photosensitized RF-mediated degradation of vitamins A, D3, and RF itself in skimmed milk was strongly reduced by the addition of small amounts of lycopene-gum arabic-sucrose microcapsules, prepared by spray-drying. Under these conditions, the bulk properties of the skimmed milk were unmodified. The main photoprotection mechanism of the milk vitamins was the efficient quenching of the 3Rf by the protein moiety of GA. Small contributions (<5%) to the total photoprotection percentage was due to both inner filter effect and 1O2 quenching by the microencapsulated lycopene. 

These results show the functional ability of GA to act as quencher of electronically excited states in food systems either as non-processed gum or spray-drying microencapsulated preparations. 

Gharsallaoui, A., G. Roudaut, O. Chambin et al. 2007. Applications of spray-drying in microencapsulation of food ingredients An overview. Food Res. Int. 40 1107-1121. 

Caprylic/capric triglyceride, cosmetically useful lipid, 7 833t Capsanthin, 24 560 Capsicum group, 23 164-165 Capsorubin, 24 560 Capsular polysaccharides, 20 455 Capsules. See also Microencapsulation extruding, 16 446 pharmaceutical, 18 708 produced by spray drying, 16 447-448 Capsule standard platinum resistance thermometers, 24 445 Captafol, 23 629, 647 Captan, 23 628 Captiva camera, 19 307 Captive hydrogen, 13 841 Captopril, 5 148... 

Microencapsulation using extrusion is mainly described for glassy carbohydrate matrices [14-16, 28-29]. The glassy carbohydrates, such as starch and maltodextrins, are melted at elevated temperature and low water contents and are intensively mixed with the active in the extrusion barrel. Extrusion has been used for volatile and unstable flavours. The shelf life of flavour oils could be extended from several months to 5 years, compared with 1 year for spray-dried materials. The main drawbacks of the technology are the high investments costs and the formation of rather large particles (500-1,000 pm). 

Desai, K.G., Park, H.J. (2005). Encapsulation of vitamin C in tripolyphosphate cross-linked chitosan microspheres by spray drying. Journal of Microencapsulation, 2, 179-192. 

Keogh, M.K., O Kennedy, B.T., Kelly, J., Auty, M.A., Kelly, P.M., Fureby, A., Haahr, A.-M. (2001). Stability to oxidation of spray-dried fish oil powder microencapsulated using milk ingredients. Journal of Food Science, 66, 217-224. 

Giunchedi P, Gavini E, Bonacucina G, Palmieri GF. Tabletted polylactide microspheres prepared by a w/o emulsion-spray drying method. J Microencapsul 2000 17(6) 711-720. 

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... 

G. A. Reineccius, The Spray Drying of Food Ingredients, in Microencapsulation of Food Ingredients, edited by B. Per Vilstrup (Leatherhead Food RA, Leatherhead, UK, 2000), pp. 151-185. 

Freitas, S., Merkle, H. P., and Gander, B. (2004), Ultrasonic atomisation into reduced pressure atmosphere—envisaging aseptic spray drying for microencapsulation, /. Controlled Release, 95,185-195. 

Favanetto, F., Genta, I., Giunchedi, E, Conti, B., and Conte, U. (1994), Spray dried albumin microspheres for the intra-articular dehvery of dexamethazone, I. Microencapsul., 11,445 154. 

Martinac, A., Filipovic-Grcic, J., Perissutti, B., Voinovich, D., and Pavelic, Z. (2005), Spray-dried chitosan/ethylcellulose microspheres for nasal drug delivery Swelling study and evaluation of in vitro drug release properties,/. Microencapsul., 22, 549-561. 

Spray drying is the most commonly used method in the food industry. Bioactive ingredients microencapsulated by this method include fats and oils, flavours, essential oils and other oil-soluble bioactives. Water-soluble bioactives can also be encapsulated by spray drying, where the encapsulant forms a matrix structure rather than a film surrounding the core. This process typically involves the dispersion of the core material into a solution of the encapsulant (e.g., protein, carbohydrate) and atomization of the mixture into the drying chamber. This leads to evaporation of the solvent... 

Hogan SA, O Riordan, E.D., and O Sullivan, M. (2003). Microencapsulation and oxidative stability of spray-dried fish oil emulsions. J. Microencapsulation 20,675-688. 

Jimenez, M., Garcia, H.S., and Beristain, C.I. (2004). Spray-drying microencapsulation and oxidative stability of conjugated linoleic acid. Eur. Food Res. Technol. 219, 588 592. 

Reineceius, G.A. (2001). The spray drying of food ingredients. In P. Vilstrup (eAI), Microencapsulation of Food Ingredients. Leatherhead Publishing, Surrey, UK, pp. 151-179. 

For polymorphic compounds, such as sulfa drugs, talc excipients induced polymorphic transformation of sulfamethoxazole during the process of microencapsulation by spray-drying,... 

Takenaka, H. Kawashima, Y. Lin, S.Y. Polymorphism of spray-dried microencapsulated sulfamethoxazole with cellulose acetate phthalate and colloidal silica, montmoril-lonite, or talc. J. Pharm. Sci. 1981, 70, 1256-1260. 

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