Nanolátices poliméricos com baixa concentração de surfactante para liberação controlada de fármaco

Abstract

The synthesis of polymeric nanoparticles with different compositions and their application as nanocarriers for controlled release of the hydrophobic drug ibuprofen were investigated. The method used for the preparation of the nanometric polymeric material and the encapsulation of the drug was the emulsion polymerization technique, stabilized by a low concentration of sodium dodecylsulfate. The monomers used were methacrylic monomers, such as methyl methacrylate (MMA), methacrylic acid (MAA) and 2-hydroxyethyl methacrylate (HEMA). The effect of several reaction parameters on the systems was investigated in order to obtain small nanoparticles and high efficiency of drug encapsulation. In this way, latex particles as small as 28 nm (analyzed by the dynamic light scattering technique) and an encapsulation efficiency of up to 99.6% of ibuprofen (measured by ultraviolet and visible spectroscopy) were achieved. However, in vitro controlled released experiments revealed that nanolatexes containing ibuprofen were not stable in a system with pH which simulated the intestinal pH.