Solid dispersion is a strategy to improve solubility of poorly water soluble drug. Solid dispersion is refers as dispersion of active ingredient in a carrier at solid state which is prepare by melting method , solvent evaporation method, melt solvent method, kneading method, spray drying method, freeze drying method, hot melt extrusion method, supercritical fluid method, melt agglomeration process, co evaporation method, co-precipitation method etc. on the basis of carriers solid dispersion is classified as first generation, second generation, third generation solid dispersion. Solid dispersion can be evaluated for various characterizations like drug carrier interaction, drug carrier miscibility, surface property, stability, amorphous content, dissolution rate.
