The responsibility for obtaining this approval lies with the company or research group carrying out the trial (called the “sponsor” in the legislation). This type of trial must be approved by the authorities in the country where it is to be conducted. If the trial has demonstrated an adequate effect and there have been no signs of unacceptable side effects in the tested animal species, the next development phase can begin, which is testing the medicine in human beings. Many trials are stopped during this development phase because the results fail to show any effect or produce unacceptable side effects. This phase is extremely costly and time-consuming and could take several years. Pharmacokinetic properties include absorption, distribution, metabolism and excretion, etc. They assess the medicine’s safety, efficacy and mechanism of action (which cells and/or processes of the body is affected by the medicine) as well as the pharmacokinetic properties in animals. Such trials must be approved by an animal ethics committee in the country concerned. These trials are called non-clinical trials or pre-clinical trials.
If the results are convincing, the next step is in vivo trials where the medicine is tested in laboratory animals. The first step in the development of a medicine is to prove the mechanism of action in a laboratory trial, a so-called in vitro trial, which means “in the glass”. Once an idea for a new medicine is born, several years of work in the laboratory proceeds before the medicine can be tested in human beings.