RESUMO
The wide use of chitosan microspheres in pharmaceutical applications, mainly in the controlled release of drugs and as a bactericidal agent, has been widely reported in the literature. However, these important biomaterial applications with multifunctionality is still scarce. In this study, epichlorohydrin-crosslinked chitosan microspheres were prepared and evaluated for Ag+ adsorption and formation of silver nanoparticles. The hybrid material obtained was used to antibacterial activity and controlled drug release. The optimal pH for adsorption of Ag+ ions in aqueous medium was pH 5-7; the best fit was the Langmuir model; the optimal time for maximum adsorption was 10 h. The highest release of the drug occured at neutral pH of the intestinal fluids and remained constant for 6 h. Silver ion microspheres demonstrated activity against E. coli and S. aureus. The concentration of ibuprofen incorporated in the chitosan microspheres was 7.9 × 10-3 mol L-1 and in the microspheres with AgNPs the concentration was 1.8 × 10-2 mol L-1. The microspheres with AgNPs released more drug (77%) than the material without AgNPs.