摘要:
Colonic-targeted oral drug dosage forms composed of a drug confined within a crosslinked hydrogel that exhibits pH-dependent swelling and is composed of an ionizable comonomer such as acrylic acid, a nonionizable comonomer such as an acrylamide, and a crosslinking agent that contains an aromatic azobond. Selective drug release in the colon occurs by a combination of pH-dependent swelling of the hydrogel and degradation of the hydrogel by enzymatic cleavage of the azobonds by azoreductases.