How are medicines made?
In the past, all medicines came from plants or animals. Although some important medicines still come from plants or animals (e.g. morphine), most medicines used today in the developed world are manufactured through chemical processes. All new medicines must undergo thorough testing before being approved for use. Before a new medicine can be tried in humans it must undergo extensive testing in the laboratory, to assess its safety and biological activity. This ‘pre-clinical’ development stage may last as long as 3 or 4 years. Then clinical trials in human volunteers, determine if a medicine is safe and effective, at what doses it works best and what side effects it causes. A typical clinical trial development programme Stage Number and type of patients Typical duration Purpose Phase I 20-100 — healthy volunteers up to 1 year — To ensure the medicine is safe and find the most suitable dose Phase II — Up to several hundred patients 1-2 years — To assess effectiveness and look for side
