Drug discovery is a process of discovering or designing new drugs or pharmaceutical molecules. In new approach or now a day's new drugs are discovered by understanding how disease or infection can be controlled at the molecular and physiological level and then target are identified based on this knowledge. New technologies like bioinformatics or data management are used to speed up the process of drug discovery.

Drug discovery is combined effort of chemist, scientist and pharmacologist, as they identify cellular or genetic factors, which are responsible for specific condition or disease. They search for substances that can target these cellular or genetic factors and will help in curing disease. Out of every 5,000 new compounds identified as effective therapeutic agent during discovery process, only five compounds are considered as safe to test on human volunteers after preclinical evaluation. At last only one of these compounds after testing in patients is marketed as drug for treatment.

Target Identification:

Scientists use various techniques to identify and learn more about cellular or genetic chemical that influence disease condition. Compounds are then identified that have strong interaction with drug target of a specific disease.

Target Prioritization:

Researchers compare each drug target on their association with a specific disease. Tests are conducted to confirm that the interactions with the drug target are associated with desired change in the disease condition. Scientists then identify compounds that have desired effect on the selected target.

Lead Identification:

Lead compound is the one that compound believed to have the required potential to treat and cure a specific disease. In the lab scientists compare effect of new substance to that of already known substance to determine the likelihood of success of this new compound.

Lead Optimization:

Lead optimization compares the effect of all the lead compounds and helps pharmaceutical and biotechnology companies to select the compound with greatest potential to be developed into effective and safe medicine to treat that particular disease. Often lead prioritizations are conducted in living organisms or in cell culture to know the effectiveness of these lead compounds.

Drug Development:

Only small fractions of compounds are approved as safe and effective drug to treat specific disease, hence it is a very costly and intensive process. Only after rigorous testing for around 12 to 15 years about safety, efficacy and effectiveness of the target compound, government authorities will give permission to pharmaceutical company to market and sell the drug.

Clinical Study:

Clinical study consists of three phases known as Phase-I, Phase-II and Phase-III. In each successive phase of clinical trial, number of patients being tested on target drug increases.


In phase-I clinical study safety and tolerability of target drug in humans are tested for six to nine months. Small group of healthy humans are used as subjects to test thepharmacokinetics and pharmacodynamics of target drug.


In phase-II clinical study targeted drug are being tested for its efficacy and tolerability on several hundred patients with the condition the drug is designed to treat. This verifies safety and effectiveness of the drug in treating condition and also maximum and minimum tolerable dosage is also determined.


Here safety and effectiveness of target drug is investigated in randomized and blinded clinical trials, depending upon the condition or disease it treats, this phase may require one to four years of testing. Testing is done on volunteer patients suffering from the same condition to which the target drug is designed as treatment.

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