Poly polylactide microsphere

Figure 2. Solvent evaporation method for production of polylactide microspheres. The polymer (PLGA or PLA) is dissolved in an organic solvent (e.g., methylene chloride or ethyl acetate). The aqueous or solid dmg is then added, and the solution is mixed by sonication or homogenization to form the primary emulsion (solid or water in-oil), This emulsion is then transferred to water containing an emulsifying agent [e.g., poly(vinyl alcohol)]. Mixing of the primary emulsion in the water phase produces the microspheres, resulting in a secondary emulsion (solid or water in-oil-in-water). The final emulsion is diluted with excess water to facilitate removal of the organic solvent in the oil phase. The microspheres are then dried. (Reproduced om Cleland, 1995, cop)Tight Plenum Press.)...

The use of polylactides for delivery of insect hormone analogs and other veterinary compounds (115,116) has been studied. Microspheres, pellets, and reservoir devices based on polyglycolide, poly-(DL-Iactide), poly(L-lactide), and various copolymers have been used to deliver methoprene and a number of juvenile hormone analogs. ... 

Keywords. Controlled drug delivery, Drug release, Microspheres, Degradation, Erosion, Polylactide, Poly(glycolide-co-lactide), Poly(e-caprolactone), Poly(hydroxyalkanoates) Polyanhydrides, Polycarbonates, Poly(orthoesters), Poly( l,5-dioxepan-2-one)... 

Zhu KJ, Jiang HL, Dn XY, Wang J, Xu WX, Liu SF. Preparation and characterization of hCG-loaded polylactide or poly(lactide-co-glycolide) microspheres using a modified water-in-oil-in-water (w/o/w) emulsion solvent evaporation technique. Journal of Microencapsulation. March-April 2001 18(2) 247-260. PubMed PMID 11253941. 

K.J. Zhu, et al.. Preparation, characterization and in vitro release properties of ibuprofen-loaded microspheres based on polylactide, poly(e-caprolactone) and their copolymers, J. Microencapsul. 22 (1) (2005) 25-36. 

Polycondensation of aUgrl/atyl phosphoric dichlorides with hydro -telechelic oligomers [poly(glycolic acid), polylactide, and copolymers] has been used for the preparation of various PPEs with biomedical applications such as nerve guidance conduits and microspheres for drug delivery systems. ... 

The remaining polymers listed in Table I are not soluble in aqueous solutions and require organic solvents or elevated temperatures for fabrication into microspheres and encapsulation of proteins. Two recent reviews describe the use of polylactides, poly(ortho esters), and polyanhydrides, all of which have been used for the controlled release of several proteins and peptides (Langer, 1993 Heller, 1993). Polyiminocarbonates are relatively new biodegradable polymers that, like polycaprolactones, have not yet been extensively characterized as controlled release matrices for therapeutic proteins (Pulapura et al, 1990). While all of these polymers require relatively harsh conditions for entrapment of the protein, their release properties may allow for a prolonged delivery (e.g., up to one year) because... 

Polylactide is a kind of biodegradable polyester that possesses many desirable properties such as non-toxicity, hydrolyzability and biocompatibility for use for varied biomedical purposes such as sutures, fracture fixation, oral implant and drug delivery microspheres.It is popularly synthesized by the ringopening polymerization of lactide monomers which are the cyclic dimers of lactic acid. Polymerization of racemic D,L-lactide typically results in atactic, amorphous polymers named poly(D,L-lactide) (rg 60 °C), whereas polymerization of L-lactide or D-lactide results in isotactic, semicrystalline polymers called poly(L-lactide) or poly(D-lactide) (7" 180 PLA fractures... 

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