14 - Pathology Issues in the Design of Toxicology Studies

Abstract

This chapter describes pathology issues that develop in the design of toxicology studies. Toxicologic studies are carried out for compounds being developed for human use to assure the safe exposure of humans to new chemical entities (NCE). These studies should define the toxicity or hazards associated with the NCE to adequately assure safety in humans. Additionally, the effects of compounds are also studied in target animal species for compounds developed for veterinary use. NCEs that have the potential to become part of the food chain or to be present in the environment of humans or animals are also studied in order to identify their toxic effects and their possible impact on humans or other at-risk species. The number of studies that a toxicologic pathologist gets involved with is large and varied. This chapter highlights issues concerning studies leading to the registration of compounds for human use, either as a treatment or as a preventive for disease and some aspects of studies of compounds to be used in animals that may become part of the human food chain or that share the environment with humans. Major landmarks in the development of a human pharmaceutical development are the discovery and patenting of a new chemical entity, application to the regulatory agency for approval to test the drug in human clinical trials, and an application for authorization to market the drug. The chapter explores specific issues regarding the role of the pathologist in discovery, exploratory, toxicology, regulatory, mechanistic, and carcinogenicity studies.