1.3. Toxicological aspects

Publisher Summary Discussion of the toxicological aspects of impurity profiles for pharmaceutical products requires that several tenets of safety assessment be reiterated, as a baseline for building the edifice of a reasoned and rational argument that seeks to limit both the number and amount of impurities on safety grounds. Firstly, the licensing of medicinal products for sale in most countries of the world is based upon three premises, that the product will be efficacious in the disease to be treated, it will be sufficiently safe and will be of as good a quality as can reasonably be achieved, even if this is not an absolute requirement for safety. Secondly, the route and formulation by which a medicine is delivered can profoundly affect safety. Thirdly, the dose of active substance administered will vary considerably between products—at least two orders of magnitude are necessary to cover the range, which extends from micrograms to grams.