Advances in Polysaccharide-Based Oral Colon-Targeted Delivery Systems: The Journey So Far and the Road Ahead

Abstract

Various colon-targeted oral delivery systems have been explored so far to treat colorectal diseases, including timed-release systems, prodrugs, pH-based polymer coatings, and microflora-triggered systems. Among them, the microbially triggered system has gained attention. Among various oral colon-targeted delivery systems discussed, the polysaccharide-based colon-targeted delivery system has been found to be quite promising as polysaccharides remain unaffected by gastric as well as upper intestine milieu and are only digested by colonic bacteria upon reaching the colon. The major bottleneck associated with this delivery is that non-suitability of this system during the diseased state due to decrease in bacterial count at that time. This causes the failure of delivery system to release the drug even at colonic site as the polysaccharide matrix/coat cannot be digested properly due to lack of bacteria. The co-administration of probiotics is reported to compensate for the bacterial loss besides facilitating site-specific release. However, this research is also limited at the preclinical level. Hence, efforts are required to make this technology scalable and clinically applicable. This article entails in detail various oral colon-targeted delivery systems prepared so far, as well as the limitations and benefits of polysaccharide-based oral colon-targeted delivery systems.

Anti-oxidant and anti-inflammatory potential of different polymer-based mesalamine delayed-release granules in TNBS-induced ulcerative colitis in wistar rats

“…In comparison to others, the polysaccharide-based colon-targeted delivery system remains unaffected by gastric and/or intestinal milieu. This delivery mechanism is based on the bacterial count as the polysaccharides are digested by the bacteria when they reach the colon ( Ibrahim, 2023 ). However, the efficacy of this system is limited by the reduction in bacterial count in UC.…”

“…Treatment of UC focuses on the lower part of the large bowel which can be targeted by localized drug delivery in the colon ( Kayal and Shah, 2019 ). Several physiological hurdles, including different pH, transit time, microflora, drug breakdown, and absorption in the stomach and small intestine, must be overcome for the drug to reach the colon ( Ibrahim, 2023 ). Often drug delivery in the colon is hampered by several gastrointestinal (GIT) disorders.…”

Colon Delivery of Nutraceutical Ingredients by Food-Grade Polymeric Systems: An Overview of Technological Characterization and Biological Evaluation

“…Due to these numerous advantages, the scientific community has shown considerable interest in their use in the development of modified delivery systems not only for drugs, but also for nutraceuticals, pro-and prebiotics, phytoextracts, phytotherapeutics, and other natural biomolecules. The interest is in the potential use of modified delivery systems for highly biocompatible and biodegradable colon-specific drugs, as well as in the development of smart food supplements and new fortified foods useful or adjuvant to conventional therapy against major colon disorders [8][9][10][11].…”

“…Co-administration of probiotics could compensate for the bacterial loss. However, this research is limited to the preclinical level and further studies are needed for industrial scalability and clinical use of these technologies [11].…”