Amorphization is a commonly used method to enhance the dissolution of poorly water-soluble drug. In this study Kollicoat IR , a new pharmaceutical excipient developed as a coating polymer for instant release tablets, was evaluated as a carrier in solid dispersions of Indomethacin. The solid dispersions of indomethacin with kollicoat IR were prepared at ratio 1:1 by different methods such as co-grinding, solvent drop co grinding, kneading and solvent evaporation method to achieve dissolution rate enhancement. Fourier transform infra red spectroscopy, Differential scanning calorimetry, X-ray powder diffraction and nuclear magnetic resonance spectroscopy were used to evaluate the interaction or miscibility between the drug and the carrier. The pharmaceutical performance was evaluated by dissolution experiments, performed in 1 part phosphate buffer pH 7.2 and 4 parts water. The X-ray diffractogram and nuclear magnetic resonance spectroscopy indicates indomethacin transformed from the crystalline state to the amorphous state. Differential scanning calorimetry revealed molecular dispersion of drug within polymer as disappearance of characteristic melting point of crystalline drug. In stability study, amorphous IMC in the solid dispersion did not crystallize under storing room temperature for 6 month due to antiplasticizing effect of polymer. The transformation of indomethacin from crystalline to amorphous state by using Kollicoat IR is considered a promising way to improvement of drug dissolution.
