Drug discovery is a process in which a new drug is designed and developed. Generally a drug is discovered based on the knowledge of properties such as molecular geometry, activity of functional groups and electronic structure. During the drug discovery dosage analysis and pharmacokinetics are not included. Modern drug discovery involves the identification of screening hits, medicative chemistry and improvement of these hits to extend the affinity, property efficacy/potency, metabolic stability and oral bioavailability. Once a compound that fulfills all of those needs has been known, itll begin the method of drug development before clinical trials. One or additional of those steps could, however not essentially, involve computer-aided drug style. Modern drug discovery is so typically a capital-intensive method that involves massive investments by pharmaceutical business companies also as national governments. Despite advances in technology and understanding of biological systems, drug discovery remains a prolonged, "expensive, difficult, and inefficient process" with low rate of latest therapeutic discovery. Drug discovery is completed by pharmaceutical firms, with analysis help from universities. The final product of drug discovery could be a patent on the potential drug. The drug needs terribly costly clinical test, II and III clinical trials, and most of them fail. Little firms have an essential role, usually then commerce the rights to larger firms that have the resources to run the clinical trials.