According to a first embodiment, there is provided a sustained-release preparation comprising a water-insoluble or slightly water-soluble polyvalent metal salt of a water-soluble physiologically active substance which is not an endothelin antagonist, and a biodegradable polymer. The sustained-release...http://www.google.fr/patents/US6087324?utm_source=gb-gplus-shareBrevet US6087324 - Sustained-release preparation
