1. Department of Pharmaceutics, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland, Technical Research Centre of Finland (VTT), Chemical Technology, Materials Technology, P.O. Box 21, FIN-05201 Rajamäki, Finland, Technical Research Centre of Finland (VTT), Biotechnology, P.O. Box 1500, FIN-02044 VTT, Finland, and The School of Pharmacy, University of Bradford, Bradford, West Yorkshire, BD7 1DP, U.K.