A small practice, at my very own level, just to answer some questions regarding to the basic characteristics of drug molecules, having specific characteristics ,described as: Gastro-irritant Nature High First-pass effect Short t1/2, In need of Sustained action. Therefore Diclofenac Sodium works here as a Prototype drugmolecule for all such drugs. On the other hand, this work is based onto the Chronobiologic pattern of the disease Rheumatoid Arthritis. Work performed at R&D scale and the entire hard work and designing resulted in the form of an enteric-coated Bilayer Tablet,having a single drug in both the layers. Это и многое другое вы найдете в книге Design & Evaluation of Pulsatile Release System of Diclofenac Sodium (Minaxi Uniyal)