Progress in Establishing In Vitro Alternatives to Animal Experiments - Ethical and Scientific Challenges

Abstract

A short description of the history of the 3Rs concept is given, which was developed as the scientific concept to refine, reduce and replace animal experiments by Russel and Burch more than 40 years ago. In addition, the legal framework in Europe for developing alternatives to animal experiments is given and the current status of in vitro systems in pharmacology and toxicology is described including an update on metabolising systems. The decrease in experimental animal numbers during the past decade in Europe is illustrated by the situation in Germany and the contribution of international harmonisation of test guidelines on reducing animal numbers in regulatory testing is described. A review of the development of the principles of experimental validation is given and the 3T3 NRU in vitro phototoxicity test is used as an example for a successful validation study, which led to the acceptance of the first in vitro toxicity test for regulatory purposes by the OECD. In addition, a promising QSAR approach to identify the skin irritation potential of chemicals is described, which was developed at the BfR and is proposed for regulatory acceptance after critical evaluation by the European Commission. Finally, the currently accepted alternative methods for standardisation and safety testing of drugs, biologicals and medical devices are summarised.