A success of formulation depends on how efficiently it makes the drug available at the site of action. The solubility is the one of the most challenging aspects in formulation and development of dosage forms 40% of the new chemical entities currently being are poorly water soluble drug or lipophilic. Poorly water soluble drugs after oral administration often require high doses to reach therapeutic plasma concentration. Solubility is the phenomenon of dissolution of solid in liquid phase to give a homogenous system. There are various techniques which are used to improve or enhance the solubility of poorly soluble drugs, which include physical and chemical modification and other methods like salt formation, particle size reduction, solvent evaporation solid dispersion and so forth. Solid dispersion is the one of the techniques adopted for formulation of such drugs.