Colon specific delivery of therapeutics have gained much attention of pharmaceutical researchers in the recent past. Colonic specific targeting of drugs is used not only for facilitating absorption of protein or peptide drugs, but also localization of therapeutic agents in colon to treat several colonic disorders. Among various biopolymers, guar gum (GG) exhibits pH dependent swelling, which allows colon specific release of drug. GG also shows microbial degradation in the colonic environment which makes it a suitable excipient for developing colon specific drug delivery systems. The uncontrolled swelling and hydration of GG can be controlled by structural modification or by grafting with another polymeric moiety. Several graft copolymerized guar gum derivatives are investigated for colon targeting of drugs. The efficacy of various guar gum derivatives are evaluated for colon specific delivery of drugs. The reviewed literature evidenced the potentiality of guar gum in localizing drugs in the colonic environment. This review focuses on the synthesis of several guar gum derivatives and their application in developing various colon specific drug delivery systems including matrix tablets, coated formulations, nano or microparticulate delivery systems and hydrogels.

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瓜尔胶衍生物在结肠特异性药物输送中的最新进展

近年来，结肠特异性治疗递送引起了药物研究人员的广泛关注。药物的结肠特异性靶向不仅用于促进蛋白质或肽药物的吸收，而且还用于将治疗剂定位在结肠中以治疗多种结肠疾病。在各种生物聚合物中，瓜尔胶 (GG) 表现出 pH 依赖性溶胀，从而允许结肠特异性释放药物。 GG 还显示出结肠环境中的微生物降解作用，这使其成为开发结肠特异性药物递送系统的合适赋形剂。 GG 不受控制的膨胀和水合可以通过结构修饰或接枝另一个聚合物部分来控制。研究了几种接枝共聚瓜尔胶衍生物用于药物的结肠靶向。评估了各种瓜尔胶衍生物在结肠特异性药物递送方面的功效。回顾的文献证明了瓜尔胶在结肠环境中定位药物的潜力。本综述重点关注几种瓜尔胶衍生物的合成及其在开发各种结肠特异性药物递送系统中的应用，包括骨架片、包衣制剂、纳米或微粒递送系统和水凝胶。