ABSTRACT

The process of drug discovery involves the identification of candidates, synthesis, characterization, screening and finally, the assays of their therapeutic efficacy. The history of drug discovery is as old as that of human being. The history of drug discovery goes back in parallel as mankind itself. In ancient time, majority of human societies have used drugs for their treatment. Through simple trial and error approach, man discovered that berries, roots, leaves and barks could be used for medicinal purposes to alleviate symptoms of illness. Scientists have found evidence of using herbal mixtures by the Stone Age humans from Caribbean island of Carriacou. These types of drugs were discovered in South America between 100 BC and 400 BC. In that age, the drug discovery was also accompanied with drug delivery system in the form of ceramic bowls, tubes for inhaling drug fumes or powders. Even Indian subcontinent has a very rich history of using drugs. Archeologists and anthropologists helped to dig out the history of drugs, whereas biochemists, biotechnologists, molecular biologists, pharmacists, geneticists and computational biologists have contributed in designing and developing new drugs. While people during 19th and early centuries used crude plants or their extracts as folk medicine, modern society is using semisynthetic and synthetic drugs along with purified herbal medicines. Isolation of biologically active organic molecules started in the latter part of the 19th century in relatively pure form for medicinal use. Salicylic acid (precursor of aspirin from willow bark), morphine, codeine (from opium poppy), antimalarial agent quinine (cinchona, china bark) are among the first naturally occurring drugs that made a breakthrough in therapeutics. Therapeutic drugs have made a major contribution in healing the life threatening diseases and thus, increase average life expectancy almost all over the world.