Abstract Solubility enhancement is a technique used for the hydrophobic drugs. Low aqueous solubility is the major problem, due to which drugs cannot reach the therapeutic level. Most of drugs weakly acidic and weakly basic with poor aqueous solubility. Low aqueous solubility is the major problem encountered with formulation development of new chemical entities as well as for the generic development. Among all newly discovered chemical entities about 40% drugs are lipophilic and fail to reach therapeutic range due to their poor water solubility. Drug with poor water solubility cause slow dissolution rates, generally show erratic and incomplete absorption leading to low bioavailability when administered orally. The Biopharmaceutics Classification System (BCS) reflects that Class II and IV drugs have low water solubility, poor dissolution, and low bioavailability. In this article various techniques are described to increase the solubility of drugs.
Keywords Dissolution rate, BCS Classification, Solubility.