Abstract:

Ibuprofen-poly(3-hydroxybutyrate-co-3-hydroxyvalerate)nanoparticles with the diameter of 500 to 800 nm were fabricated by means of the solvent evaporation method. The effects of the type and concentration of the emulsifier,the pH value of the water phase,the mass ratio of drug to polymer and the hydroxyvalerate(HV)con-tent of the polymer on the encapsulation efficiency and drug loading of the nanoparticles were also investigated. The optimized conditions were then chosen as:the pH value of water phase 4.0,the mass ratio of drug to polymer 10:50,the HV mass fraction 6% to 10%,and the polyvinyl alcohol concentration 1%(volume fraction). Moreo-ver,chitosan and sodium alginate were absorbed on the IBU-PHBV nanoparticles via the layer-by-layer(LbL)selfa-ssembly technique,resulting in a decrease in the burst amount of nanoparticles from 70% to 15% respectively be-fore and after coating polyelectrolyte in 6 layers,thus coming to the conclusion that the combination of the solvent evaporation and the LbL self-assembly is an effective way to overcome the initial burst release of drugs.

Key words: nanoparticle, solvent evaporation method, layer-by-layer self-assembly, ibuprofen, poly(3-hydroxy-butyrate-co-3-hydroxyvalerate)