ABSTRACT
There has been an enormous effort within the pharmaceutical and biopharmaceutical industries to discover active drugs that include small molecules and therapeutic proteins for the treatment of life-threatening diseases. The R&D investment by global pharmaceutical companies amounted to approximately $90 billion as reported in 2005, up roughly by 56% from 2001 [1]. These investments may have increased further over the last 3 years. The advances made in pharmaceutical and medical
research have signifi cant impact in improving the treatment of common diseases such as heart disease, diabetes, and cancer in particular, as well as rare disorders such as cystic fi brosis and sickle cell anemia. Over 300 new medicines have been approved by Food and Drug Administration (FDA) in the last decade alone [2]. The drug discovery process, however, is encountering more challenges in the successful translation of emerging drug concepts into successful marketed products. Some of the marketed products were withdrawn due to adverse side effects. The overall development process has become more diffi cult because of expanded regulatory and marketing requirements that necessitate additional preclinical and clinical studies prior to a new drug application submission. The attrition rate of the recommended drug candidates during clinical trials is continuing to rise with about 60% of the compounds leading to the termination of drug development programs [3]. The discovery and development of a new drug costs about $1.7 billion, and it may take up to 10-12 years for the drug to reach the market [4].
