Division of Product Quality Research, Office of Testing and Research, Office of Pharmaceutical Science, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Springs, MD 20993, USA.
Pharm Dev Technol. 2012 Sep-Oct;17(5):521-40. doi: 10.3109/10837450.2012.696268. Epub 2012 Jun 8.
Colorectal cancer (CRC) is the third most common cause of cancer-related death in both men and women. Often, surgical intervention remains the choice in treating CRC. Traditional dosage forms used for treating CRC deliver drug to wanted as well as unwanted sites of drug action resulting in several adverse side effects. Targeted oral drug delivery systems are being investigated to target and deliver chemotherapeutic and chemopreventive agents directly to colon and rectum. Site-specific delivery of a drug to colon increases its concentration at the target site, and thus requires a lower dose with reduced incidence of side effects. The major obstacle to be overcome for successful targeting of drug to colon through oral route is that drug absorption/degradation must be avoided in stomach and small intestine before the dosage form reaches colon. The review includes discussion of physiological factors that must be considered when targeting drugs directly to colorectal region, an outline on drugs used for treatment and prevention of CRC, and a brief description of various types of colon-targeted oral drug delivery systems. The focus is on the assessment of various formulation approaches being investigated for oral colon-specific delivery of drugs used in the treatment and prevention of CRC.
结直肠癌（CRC）是男性和女性癌症相关死亡的第三大常见原因。通常，手术干预仍然是治疗 CRC 的选择。用于治疗 CRC 的传统剂型将药物输送到需要药物作用的部位以及不需要药物作用的部位，导致许多不良反应。目前正在研究靶向口服药物传递系统，以便将化疗药物和化学预防剂直接靶向并递送到结肠和直肠。将药物靶向递送到结肠特定部位可增加其在靶部位的浓度，因此需要降低剂量，减少不良反应的发生。通过口服途径成功靶向药物到达结肠的主要障碍是，在剂型到达结肠之前，必须避免药物在胃和小肠中的吸收/降解。本综述包括讨论在将药物直接靶向结直肠区域时必须考虑的生理因素，概述用于治疗和预防 CRC 的药物，并简要描述各种类型的结肠靶向口服药物传递系统。重点是评估正在研究的各种制剂方法，以实现用于治疗和预防 CRC 的药物的口服结肠特异性递送。
