Oct 09, 2002· 1. Pharmaceutical composition based on rhein or diacerein for administration by oral, rectal or cutaneous (percutaneous or transdermal) route, having improved bioavailability, characterized in that it comprises rhein or diacerein, or one of their pharmaceutically acceptable salts or esters, and sodium lauryl sulfate, comicronized, in a weight ratio comprised between 3:1 and 10:1.