Poly(methylmethacrylate)-poly(vinyl pyrrolidone) (PMMA-PVP) microspheres loaded with cefadroxil (water-soluble) and indomethacin (water-insoluble) drugs have been prepared by the dispersion polymerization technique using PVP as a steric stabilizer. Microspheres have been characterized by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and X-ray diffraction (X-RD) studies. DSC studies indicated coating of PVP onto PMMA microspheres. SEM suggested the formation of microspheres in the size of around 5 mu m. X-RD confirmed that drug has been highly dispersed in polymer particles. Higher encapsulation efficiency of up to 84% was achieved for hydrophobic drug, indomethacin than for hydrophilic cefadroxil. In vitro release studies performed in pH 7.4 phosphate buffer saline indicated that release of indomethacin was controlled up to 12 h, whereas cefadroxil was released in a controlled manner up to 10 h. During in vitro release, properties of both the drugs remained unaltered. (c) 2007 Wiley Periodicals, Inc.