Colorectal cancer management: strategies in drug delivery

Introduction Colorectal cancer (CRC) is the third most common cancer leading to death worldwide following breast and lung cancer with the incidence rate of 10%. The treatment comprises surgery, radiation, and ablation therapy depending upon the stage of cancer. Areas covered The review focuses on various drug delivery strategies explored to circumvent the major constraints associated with the conventional drug delivery systems-poor bioavailability, intra- and inter individual variability, exposure of normal cells to antineoplastic agents, and presence of efflux pump. All these attributes impact the effective delivery of chemotherapeutic agents at the tumor site. The various target specific drug delivery systems developed for colorectal cancer include pH-dependent, microbiologically triggered, time-dependent, magnetically driven, pressure-dependent, prodrug/polysaccharide-based, osmotic and ligand-mediated systems. This review enumerates novel target specific approaches developed and investigated for potential utility in CRC therapeutics. Expert opinion The limitations of conventional delivery systems can be overcome by the development of colon-specific targeted drug delivery systems that overcome the obstacles of nonspecific biodistribution, drug resistance, and unwanted adverse effects of conventional drug delivery systems. In addition, nanotechnology approaches help to increase drug solubility, bioavailability, reduce side effects, and provide superior drug response in CRC.