Alternatives to In vivo Studies in Toxicology

Toxicology or its appplied product evaluation function (also called safety assessment) has now been in the forefront of the public's interest and expectations since at least the Second World War. As our understanding increased, a range of test designs and experimental methods using intact higher animals rapidly developed and came to be accepted in regulation and law. However, as we have come to understand more of both how biological systems work and of the molecular and cellular mechanisms that underlie specific toxicities, we have also come to understand that intact higher animals may not be the only model system that allows us to identify and evaluate adverse effects resulting from exposure to a drug or chemical. Since the early 1980s, this has lead to extensive efforts to develop and validate non-animal methods. And to use these to the extent possible to take the place of intact animals in the identification and evaluation of hazards for regulatory purposes. This chapter seeks to capture the current breadth and status of that journey. Keywords: In Vitro Models; Alternative Models; 4 Rs; Regulatory acceptance