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Comparative evaluation of ammoniated aqueous and organic-solvent-based cellulose ester enteric coating systems: a study on free films

Abstract:

The permeability and mechanical properties of ammoniated aqueous and organic-solvent-based enteric films were evaluated with free films and with the films applied to tablets. The enteric coating materials studied were cellulose acetate phthalate (CAP), cellulose acetate trimellitate (CAT) and hydroxypropyl methylcellulose phthalate (HPMCP, HP-50) plasticized with triacetin. Enteric films prepared from organic-solvent-based solutions showed lower permeability to basic drug (caffeine) and hydronium ions, and the permeability decreased in the sequence CAT, HP-50, CAP. As regards mechanical and stress-strain properties, ammoniated aqueous enteric films appeared to be somewhat weaker and more brittle than corresponding films prepared from acetone-based solutions. The results suggest very acceptable resistance of organic-solvent-based enteric films against short-term storage under tropical conditions. © 1994.