An aromatic polyanhydride having a repeating unit with structure (I) wherein Ar is a substituted or unsubstituted aromatic ring and R is a difunctional organic moiety substituted on each Ar ortho to the anhydride group. Ortho-substituted bis-aromatic dicarboxylic acid anhydride monomers and ortho-substituted bis-aromatic dicarboxylic acid intermediates thereof are also disclosed, as well as implantable medical devices, such as scaffolding implants for tissue reconstruction, drug delivery systems prepared from the aromatic polyanhydrides, as well as therapeutic oral dosage forms and treatment methods.