1. Pharmaceutical Physics Laboratory, Boehringer Ingelheim Pharma GmbH and Co. KG, Ingelheim, Germany.
2. Children's Hospital, Evangelisches Krankenhaus Hamm, Germany.
3. Clinical Pharmacokinetics, Translational Medicine and Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH and Co. KG, Ingelheim, Germany.
4. Children's Hospital, Allergology, Pneumology and Cystic Fibrosis, Goethe-University, Frankfurt am Main, Germany.