Nano based enemas for colon targeting

Colon-specific drug delivery systems (CDDSs) are pivotal for addressing localized drug delivery for ulcerative colitis, Crohn's disease, irritable bowel syndrome, chronic pancreatitis, and colonic cancer. Moreover, the colon offers a method of absorption of drugs that can be used to treat ailments beyond the colon. Proteins and peptides, susceptible to degradation in the harsh gastric environment, can be absorbed systemically if delivered intact to the colon's mucosa. Targeting drug delivery specifically to the colon is crucial for effective therapeutics. Various formulation strategies have been explored to prepare colon-targeted drug delivery systems. These approaches leverage formulation components interacting with gastrointestinal physiology aspects such as pH gradients, colonic microflora, and enzymes. Most research focuses on oral administration for colon targeting, whereas limited investigation centers on nano-based enemas, which may circumvent oral route limitations. This chapter summarizes the factors impacting colon-specific drug delivery, colonic bioavailability, and associated CDDS limitations. Furthermore, it offers a comprehensive analysis of conventional and emerging formulation approaches and technologies currently deployed in enema-based CDDS development.