1. A/S Alfred Benzon, 29 Halmtorvet, DK-1700 Copenhagen, Denmark
2. Department of Pharmacy, University of Nottingham, Nottingham
3. Department of Medical Physics, Queen's Medical Centre, Nottingham
4. Department of Physiology and Pharmacology, Medical School, University of Nottingham, Nottingham
5. School of Pharmacy, Leicester Polytechnic, Leicester, UK