The enhancement of the oral bioavailability is currently one of the greatest challenges in the development of poorly water soluble drugs. The main objective of work to enhance solubility of Simvastatin (SIM) by use of natural polymer, chitosan (CHI) to produce cost effective formulation.Physical mixture, co-grinding method, spray drying method are compared.Co-grinding method applied for preparation of drug polymer complex and compared with the solubility and dissolution of marketed preparation.