1. Laboratory of Drug Analysis, Department of Pharmaceutical Analysis, Ghent University, Harelbekestraat 72, B-9000 Gent, Belgium, Department of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians-University, Butenandtstrasse 5-Building B, D-81377 Munich, Germany, Freeze Drying Department, GSK Biologicals, Rue de l’Institut 89, B-1330 Rixensart, Belgium, and Laboratory of Pharmaceutical Technology, Department of Pharmaceutics, Ghent University, Harelbekestraat 72, B-9000 Gent, Belgium