Pulmonary Deposition | bioequivalence.eu

Pulmonary Deposition

Pulmonary deposition can be investigated by imaging studies or pharmacokinetic studies, but the clinical relevance of pulmonary deposition studies is limited by lack of accuracy and from the lack of evidence on the importance of the distribution of drug within different zones of the lung.

Imaging studies are not recommend in children due to radiation from the tracer and due to unknown impact on the properties of the active substance and the excipients from the radiolabeling. Currently the experience with such studies would appear to be insufficient for documenting bioequivalence.

Pharmacokinetic studies from plasma or urine have the advantage of being able to demonstrate linear dose-response relationships. In addition, pharmacokinetic studies measure total systemic exposure (for assessment of safety), and pulmonary absorption (for assessment of pulmonary deposition and efficacy) can be separated from gastrointestinal absorption.

Professor Hans Bisgaard • Copenhagen • Denmark • Bisgaard@copsac.com