Biomedical Polymers Group, Department of Pharmaceutics, The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, UK; Centre for Polymer Therapeutics, Welsh School of Pharmacy, University of Wales, King Edward VII Avenue, Cardiff, CF10 3XF UK; and A. P. Pharma, 123 Saginaw Drive, Redwood City, California 94063 (At 2001-12-18)