COLON TARGETED DRUG DELIVERY SYSTEMS APPLICATION AND FORMULATION CONSIDERATION: A REVIEW
Satyam Pahariya, Akanksha Tiwari, Rekha Rani, Priyanka Keshri
ABSTRACT
Colon targeted drug delivery systems (CTDDS) have emerged as an effective approach for the site-specific delivery of therapeutic agents to the colon, thereby improving treatment efficacy and minimizing systemic side effects. The oral route remains the most preferred method for colon targeting due to its convenience, patient compliance, and formulation flexibility. Conventional drug delivery systems often fail to deliver adequate drug concentrations to the colon for the treatment of disorders such as ulcerative colitis, Crohn’s disease, colon cancer, and amoebiasis. Therefore, specialized colon-specific delivery systems are required to achieve localized and controlled drug release. Various physiological factors, including colonic pH, transit time, microflora, and enzymatic activity, play a crucial role in the design and performance of CTDDS. Different approaches such as pH-dependent, time-dependent, bacterial enzyme-triggered, pressure-controlled, osmotic-controlled, and combined systems have been extensively investigated for effective colon targeting. Natural polysaccharides such as chitosan, pectin, guar gum, alginate, and dextran have shown promising potential due to their biodegradability and susceptibility to colonic bacterial degradation. In vitro and in vivo evaluation techniques are essential for assessing the performance and site specificity of CTDDS. Colon-targeted systems offer several advantages including reduced dosing frequency, improved bioavailability, minimized gastric irritation, and enhanced local therapeutic action. However, challenges such as variable gastrointestinal conditions, limited drug absorption, and lack of ideal in vitro models still remain. Recent advances in nanotechnology and polymer science may further enhance the development of efficient and reliable colon-targeted drug delivery systems in the future.
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