1. Department of Chemical Engineering, Massachusetts Institute of Technology, Building E25, Room 342, Cambridge, MA 02139
2. Lehrstuhl für Pharmazeutische Technologie, Universität Erlangen-Nürnberg, Cauerstrasse 4, 91058 Erlangen, Germany
3. Laboratoire de Chimie Physique Macromoleculaire, Ecole Nationale Supérieure des Industries Chimiques, 1 rue Grandville, 54001 Nancy Cedex, France
4. Laboratorio de Farmacia Galénica, Facultad de Farmacia, Universidade de Santiago de Compostella, 15706 Santiago de Compostella, Spain
5. Research Center for Biomedical Engineering, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606, Japan