Drug research is a specific process toward the development of new therapeutic agents in this era to meet the current medical needs. Drug discovery and development are the two major stages in the development of new therapeutic drug substance. Drug discovery involves identification and characterization of new targets (enzymes or receptors), synthesis of new lead molecules, screening of new lead molecules for its in vitro and/or in vivo biological activities, and physicochemical characterization of leads. The drug discovery and development process requires close interaction among the different scientific discipline members for as many as 10–12 years. It is estimated that only 1 out of 5000 screened compounds is approved as a new drug. On an average, every new drug molecule requires 12±15 years to reach the patient and costs a staggering amount of US $ 400±650 million .Active pharmaceutical ingredient (API): Any substance or mixture of substances intended to be used in the manufacture of a pharmaceutical dosage form and that, when used so, becomes an active ingredient of that pharmaceutical dosage form