Patent ID: 6383470
Filing Date: 2002-05-07
Classification: A61K

Abstract:
Microcapsules having a core defined by a wall material comprising a copolymer of at least one synthetic polymeric material and at least one biopolymer, whereina) the biopolymer exhibits site-specific, structure-specific or tissue-specific properties or b) the biopolymer has functional groups, by which, optionally, chelating ligands or their metal complexes and/or site specific, structure-specific or tissue-specific substances are bound, c) the synthetic polymeric material has a hydrophobic alkylbackbone, and d) optionally, the wall material contains one or more pharmaceutically active ingredient(s) and wherein the core of the microcapsules comprisesa) a gas or gas mixture, b) one or more pharmaceutically active ingredients or c) the same material as the capsule wall, provided that the synthetic polymeric material is not made of polymerizable aldehydes, and wherein the weight ratio of biopolymer to synthetic polymeric material is in the range of 10:90 to 80:20 and wherein the microcapsule size is 0.5 to 8 &mgr;m.