Nirma University, Institute of Pharmacy , Department of Pharmaceutics and Pharmaceutical Technology, Ahmedabad, Gujarat, India.
Expert Opin Drug Deliv. 2011 Jun;8(6):779-96. doi: 10.1517/17425247.2011.574121. Epub 2011 Apr 21.
Colon targeting has gained increasing importance for the topical treatment of diseases of the colon, such as Crohn's disease, ulcerative colitis, colorectal cancer and amebiasis. Various strategies used for targeting drugs to the colon include formation of a prodrug, coating with time or pH-dependent polymers, use of colon-specific biodegradable polymers, osmotic systems and pressure-controlled drug delivery systems. Among the different approaches used, polysaccharides that are precisely activated by the physiological conditions of the colon hold great promise, as they provide improved site specificity and meet the desired therapeutic needs.
This review aims to summarize the natural and modified properties of polysaccharides that are responsible for their colon targeting abilities. Emphasis is placed on describing formulation approaches that use polysaccharides as a strategy for targeting drugs to the colon.
Polysaccharide-based colon-targeted drug delivery systems are effective when they are precisely activated by the physiological conditions of the colon. Absence of enzymes during colonic disorders might hinder the activation of the delivery system. To guarantee delivery of the drug to the colon, it is preferable to combine polysaccharides with enteric or cellulose polymers.
结肠靶向在局部治疗结肠疾病（如克罗恩病、溃疡性结肠炎、结直肠癌和阿米巴病）方面的重要性日益增加。将药物靶向递送至结肠的各种策略包括前药形成、用时间或 pH 依赖性聚合物包衣、使用结肠特异性可生物降解聚合物、渗透系统和压力控制药物递送系统。在使用的不同方法中，通过结肠的生理条件精确激活的多糖具有很大的应用前景，因为它们提供了更好的靶向特异性并满足了所需的治疗需求。
本综述旨在总结负责多糖结肠靶向能力的天然和修饰性质。重点描述了将多糖用作将药物靶向递送至结肠的策略的制剂方法。
当多糖基于药物的结肠靶向递送系统通过结肠的生理条件精确激活时，该系统是有效的。在结肠疾病期间缺乏酶可能会阻碍递药系统的激活。为了确保药物递送至结肠，最好将多糖与肠溶性或纤维素聚合物结合使用。
