Drug is a chemical which alters the processes in the organism, which is used in the medicine for prevention, diagnosis and treatment of the diseases (Farlex, 2011). Drug discovery is a long term process that needs money investment. The process of drug investigation takes approximately from 9 to 15 years during which the number of chemicals that can become drug is reduced from 10,000 to 1-2 (Saparov, 2011). Even after manufacturing the drug is studied by scientists for modifying its structure, delivery and effects on the organism. Drug discovery consists of several stages which help to examine its effectiveness and side effects.
Pre-discovery process is the first stage of drug discovery. During Pre-discovery stage chemists and pharmacologists endeavor to understand and identify the factors which can play a significant role in the particular disease. After revealing the cause of disease or understanding it a target molecule against which drug will act is being chosen. In order to understand the structure the target molecule is eliminated, isolated and its various interactions are inquired. Understanding interactions of the molecule can be helpful in finding treatment of a specific disease. Next stage includes the demonstration that the chosen molecule is relevant to the disease and proof that the drug target is associated with a desired change in the behavior of diseased cells (PPD, 2011).
The second stage of the discovery process is a drug discovery itself. Its main goal is to find a lead compound. Lead molecule is a promising compound that has a potential to become drug. There are several ways to find the lead compound, they include nature, de novo, high- throughput screening and biotechnological methods. For many centuries drugs used for treating diseases were found in nature. However, even though nature offers possible sources for drugs, currently, new methods of drug discovery are used. For instance, de nova method uses chemistry knowledge and advanced computer technologies for designing and creating the drug molecule. Another method by which lead compounds can be found is high-throughput screening method that analyses thousands of possible molecules, and among them only several ones are selected. Biotechnological methods are also used for finding lead compounds by genetic engineering of living systems to produce disease fighting biological molecules (Innovation, 2007). Next stage of drug discovery includes safety tests in vivo or in vitro. They help to study drug absorption, distribution, metabolism and secretion. After acquiring the results scientists can alter the lead compound to make it safer, by decreasing its reactivity with other compounds to reduce side effects. Next, the optimization of the structure of lead compound comes, then preclinical testing is conducted on animals to understand whether drug is safe for testing in humans (Saparov, 2011).
The stage of drug development during is next to drug discovery during which...