Microparticles solvent effects

Meng FT, Ma GH, Qiu W, Su ZG. W/O/W double emulsion technique using ethyl acetate as organic solvent effects of its diffusion rate on the characteristics of microparticles. J Control Release 2003 91(3) 407-416. 

Birnbaum DT, Kosmala JD, Henthorn DB, Brannon-Peppas L. Controlled release of beta-estradiol from PLAGA microparticles The effect of organic phase solvent on encapsulation and release. Journal of Controlled Release. April 3, 2000 65(3) 375-387. PubMed PMID 10699296. 

Precipitation/Crystallization to Produce Nano- and Microparticles Because fluids such as C02are weak solvents for many solutes, they are often effective antisolvents in fractionation and precipitation. In general, a fluid antisolvent may be a compressed gas, a gas-expanded liquid, or a SCF. Typically a liquid solution is sprayed through a nozzle into CO2 to precipitate a solute. As CO2 mixes with the liquid phase, it... 

In the other procedure, Rojas et al. [215] optimized the encapsulation of BLG within PLGA microparticles prepared by the multiple emulsion solvent evaporation method. The role of the pH of the external phase and the introduction of the surfactant tween 20, in the modulation of the entrapment and release of BLG from microparticles were studied. Better encapsulation of BLG was noticed on decreasing the pH of the external phase. Addition of tween 20 increased the encapsulation efficiency of BLG and considerably reduced the burst release effect. 

It was soon found that HPH is more effective for the production of submicronsized dispersions of solid lipids than is high-shear mixing or ultrasound [11-13], Dispersions obtained in this way are called SLN. Most SLN dispersions produced by HPH are characterized by an average particle size of around 100 to 200 nm and a low microparticle content. Alternative production procedures were also investigated, including the combination of organic solvents and HPH (HPH/solvent evaporation) [14], the dilution of microemulsions [15,16], and solvent injection [17],... 

Lee SC, Oh JT, Jang MH, Chung SI. Quantitative analysis of polyvinyl alcohol on the surface of poly(D, L-lactide-co-glycolide) microparticles prepared by solvent evaporation method Effect of particle size and PVA concentration. Journal of Controlled Release. May 20, 1999 59(2) 123-132. PubMed PMID 10332048. 

In another example of a hybrid DDS, ranitidine hydrochloride, the H2 histamine receptor inhibitor, was intercalated in MMT and coated with the cationic polymer Eudragit ElOO using an oil-in-water solvent evaporation method. The material obtained had the form of microparticles. It vras found that in the presence of Eudragit ElOO, both the release rate and the amount of drug released noticeably increased, because of the effective exchange of the polycation with intercalated drug molecules. In a similar... 

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