subject: The Process Of Drug Discovery [print this page] Medicine has always existed - since the earliest ages of civilization healers have looked for efficient cures for the many diseases and conditions that affected mankind. In the beginning, all that was available came from the surrounding natural elements (minerals, plants, animal parts), and men have experimented with various ways in which to apply these remedies: ingesting them, rubbing them on their skin, inhaling their vapors etc. Some of these natural extracts went on to be used in modern medications, their properties having been discovered most often at the end of an intentional series of experiments, others having been stumbled upon.
The term widely approved of in the latter case is serendipitous discovery, a term invented by literary man Horace Walpole to name that type of discovery which comes by chance to a person while he or she were looking for something different. Walpole stresses the fact that, for serendipity to occur, the finder must be sagacious and ready to see what he has unintentionally discovered. Toward the end of the 18th century, British chemist Humphry Davy was conducting experiments on various gases, including nitrous oxide (laughing gas). While attempting to prove its efficiency in alleviating hangovers (incidentally reports were positive), he also found that laughing gas took away most of the pain in a conscious person. As chance would have it, it would be almost fifty years before nitrous oxide was used in dentistry as an anesthetic and that role it still plays even in our days.
However, in contemporary pharmaceutics, little room is left for serendipitous discovery, since researchers can now test hundreds of new derivatives and their effect on hundreds of targets, old or new. Target is a simple and somewhat generic term for any cellular structure that has been found to blame for any particular disease. These targets are dubbed old or new depending on how much information there is on said malady. Once a series of pure chemical substances have been isolated, they are run against hundred of targets, to see which ones react the most - this process is known as high-throughput screening or HTS.
When such a test has shown that a certain candidate has an above-the-line effect on a target, that molecule goes on to be assessed from other, equally important, points of view. The most crucial aspect is that of toxicity, the negative impact on various organs in the human body - initially test are run on samples of tissue, and afterward, should the result be positive, on experimental animals. Other things researchers test for during this phase of drug discovery are: stability in various environment conditions (light, humidity, temperature), the most efficient form of administration (tablets, capsules, spray, drops etc.) and dosage possibilities.
The end phase of drug discovery is also the most important and relevant one - clinical trials on human beings. The institutions empowered to approve a new drug on the market impose very strict regulations that include four levels of clinical trials, starting from a small echelon of subjects and ending with as much as 3000, from multiple centers across the globe. The persons who sign up for these trials are not told whether they are actually taking the drug or are part of the witness group (given placebo or a different drug, for comparison), and most often not even the doctors administering the drug know which patients belong to which group - this is known as the double-blind method. Overall, the emergence of a new drug, on average, takes around 10 years and costs around 800 million US dollars.
