In vivo animal models

The lung is a preferential site of drug delivery for new pharmaceuticals and particular biopharmaceuticals. Standard models for efficacy testing and the standard toxicology battery often fail to predict the value of inhalation therapy. Therefore new strategies have to be developed. The respective ICH guideline for biopharmaceuticals (S6) does not give universal guidance since it recommends case by case investigations. for inhalational drugs it is essential to have an animal model in whisch the test substance is biologically active, but in addition the delivery of the substance should be comparable tothe human application. The aim of this contribution was to enable the reader to select the "relevant species" for testing inhalational drugs. Therefore, several often used animal models were compared on the basis of their anatomical, physiological, toxicological and immunological properties. In addition, critical issues of lung application and bioavailability of inhaled biopharmaceuticals were discussed and techniques of measuring lung toxicology and determining pharmacokinetic data were described. Furthermore, relevant disease models like asthma and COPD were shortly introduced.