Microencapsulation solvent extraction

Freitas S, Walz A, Merkle HP, Gander B (2003) Solvent extraction employing a static micromixer a simple, robust and versatile technology for the microencapsulation of proteins. J Microencapsulation 20 67-85 FZK Press release 13 (2005) http //www.fzk.de/fzk/idcplg IdcService=FZK node=2374 document=ID 050927. Cited 6 July 2005 Gavriilidis A, Angeli P, Cao E, Yeong KK, Wan YSS (2002) Trans IChemE 80/A 3... 

Dittrich, M. Hampl, J. Soukup, F. Branched oligoester microspheres fabricated by a rapid emulsion solvent extraction method. J. Microencapsul. 2000,17 (5), 587-598. 

Bleich J, Mueller BW. Production of drug loaded microparticles by the use of supercritical gases with the aerosol solvent extraction system (ASES) process. J Microencapsul 1996 13 131-139. 

Ereitas S, Merkle H P, Gander B (2005). Microencapsulation by solvent extraction/ evaporation reviewing the state of the art of microsphere preparation process technology. /. Control. Rel. 102 313-332. 

Elkharraz K, Ahmed AR, Dashevsky A, Bodmeier R. Encapsulation of water-soluble drugs by an o/o/o-solvent extraction microencapsulation method. International Journal of Pharmaceutics. May 16, 2011 409(l-2) 89-95. PubMed PMID 21356287. 

A 5% (w/v) solution of PLGA in DCM was fed through a nozzle to form a cylindrical jet. The nozzle was excited by an ultrasonic transducer of adjustable frequency. The particles were collected in 1% (w/v) PVA solution for solvent extraction/evaporation. Figure 47.10 gives the schematic representation of microencapsulation by jet excitation. 

Bleich, J. and Muller, B.W. (1996) Production of Drug loaded microparticles by the Use of Supercritical Gases with the Aerosol Solvent Extraction System (ASES) Process, Microencapsulation 13,131-139. 

Biodegradable copolymers of fumaric anhydride and isophthalic anhydride were synthesised by the melt condensation polymerisation of purified prepolymer mixtures and formulated into microspheres loaded with theophylline and diltiazem hydrochloride using a solvent extraction procedure. The important parameters of the microencapsulation process were identified and in vitro... 

Modified Conventional Methods The w/o/w solvent evaporation or extraction is probably one of the most widely used methods for peptide and protein microencapsulation [44], despite its many drawbacks. Improvements and alternatives have therefore been proposed such as oil in water (o/w), o/w (the asterisk including cosolvent) and oil in oil (o/o) [50],... 

Sah, H. Microencapsulation techniques using ethyl acetate as a dispersed solvent effects of its extraction rate on the characteristics of PLGA microspheres. J. Controlled Release 1997, 47 (3), 233-245. 

Ilic et al. (2009) used a mixture of acetonitrile and water (80 20, v/v) as the solvent for the extraction of the drug from the microparticles. Then, the drug was quantified by high efficiency liquid chromatography—HPLC. In a study of insulin microencapsulation, the authors proposed that microparticles were initially stirred in a vortex with chloroform, and then insulin was extracted with HCl 0.01 M. After that, the solution was centrifuged and, in the end, insulin was quantified by HPLC (Maschke et al., 2007). 

Rational for Microencapsulation by Solvent Evaporation/Extraction Method.982... 

This is another innovative emulsion technique proposed for the efficient encapsulation of hydrophilic drug compounds involves the formation of double emulsions (multiple emulsions). In this technique, an aqueous core solution (W,) is emulsified in a polymer-organic solvent solution (O) to form the primary W/0 emulsion, which is further emulsified in an external aqueous solution (Wn), giving rise to the double emulsion of Wi/O/Wu type. Evaporation or extraction of the organic solvent yields a solid microcapsule with an aqueous core. The organic phase in (O) acts as a barrier between the two aqueous compartments, W, and Wu, to prevent the diffusion of hydrophilic drug compounds out of the core toward the external aqueous solution. Figure 45.5 depicts the microencapsulation by the Wi/O/Wn emulsion technique. 

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