The aim of this study was to prepare and characterize a novel type of starch-coated microparticles (MPs) allowing site-specific delivery of bioactives to the colon. An oral colon-specific controlled-release system was developed in the form of MPs coated with a resistant starch (RS2/RS3) film (RS@MPs) through an aqueous suspension coating process. The RS2 was chosen from a high-amylose cornstarch with 88.5% digestion resistibility. The RS3 was prepared by a high-temperature/pressure (HTP) treatment, with the following of enzymatic debranching, and retrogradation, resulting in a dramatic increase in enzymatic resistance (RS3 content: 76.6%). RS@MPs showed 40.7% of 5-aminosalicylic acid release within 8 h. The in vivo study of fluorescein-loaded RS@MPs indicated the high acidic and enzymatic resistibility of RS@MPs and a restrained release in the upper GIT. Therefore, RS@MPs has revealed to be a high potential system for accurately targeting bioactive compound delivery to the colon.

这项研究的目的是准备和表征新型的淀粉包覆的微粒（MPs），允许将生物活性物质定点递送至结肠。通过水性悬浮液包衣工艺开发了以抗性淀粉（RS2 / RS3）膜（RS @ MPs）包被的MP形式的口服结肠特异性控释系统。RS2选自具有88.5％消化抗性的高直链玉米淀粉。通过高温/高压（HTP）处理制备RS3，随后进行酶促支化和回生，导致酶抗性显着提高（RS3含量：76.6％）。RS @ MPs显示8小时内释放了40.7％的5-氨基水杨酸。在体内荧光素的RS @ MPs的研究表明，RS @ MPs具有很高的酸性和酶抗性，并且在上部的GIT中抑制释放。因此，RS @ MPs已被揭示为一个高潜力的系统，可以准确地将生物活性化合物靶向结肠。