Author: Sinha, V.R.; Kumria, R.
Polysaccharides are bacterial enzymes have been used extensively in targeting of the drugs. Various polysaccharides have been investigated for colon specific drug delivery, natural polymers exhibit potential for drug delivery as they are comprised of polymers with a wide range of molecular weights resembles in the indigestion in the stomach and the small intestine, a large number of derivatizable groups, moreover, the polysaccharides are inexpensive, naturally occurring, abundantly available and varying chemical compositions, the most favorable property of these materials is their approval as pharmaceutical excipients, here we provide an overview on polysaccharide-based colon specific drug delivery system, drug delivery that involve a general overview of the gastrointestinal tract, the pH of different gastrointestinal regions, digestive enzymes that are secreted in mouth, stomach and intestines, and the microflora that are presented in colon region. Properties, mechanisms, applications, and patents of various polysaccharides that can be used to target the colon, gastrointestinal tract begins in the mouth, then the esophagus and reaches to the stomach, small and large intestine, and finally to the anus. The tube that initiates from the mouth to the anus in which the movement of muscles took place and release of hormones exist and digestion of enzymes took place. The gastrointestinal tract initiates with the mouth and goes through the esophagus, stomach, duodenum, small intestine then moves to the large intestine (colon), rectum and, finally, the anus, which is also known as alimentary canal, digestive tract and, perhaps commonly known as the GI tract. In an adult male human, the Gastrointestinal (GI) tract is 5 meters (20 ft) long, or up to 9 meters (30 ft) without the effect or action of muscle tone, and comprises of the upper and lower GI tracts, with regard to the rectal route, the drugs do not always reach the specific sites of the colonic disease and the sites of colonic absorption. To reach the colon and to be able to specifically deliver and absorbed there, the dosage form must be formulated taking into account the likely obstacles of the gastrointestinal tract. That is, pH, microflora, enzymes, reducing medium and transit time, pH dependent system, formulation which is coated with enteric polymers release the specified drug when pH moves towards alkaline side, Time released system, Based on the conceptual mode of delaying the release of drug after a lag time of 3-5 hours that is equivalent to small intestine transit time, Pressure dependent system, Based on conceptual mode of the strong peristaltic waves that lead to a temporary increase in luminal pressure in the colon, Microbially triggered system Polysaccharides, Drug are released following degradation of the polymer due to the action of colonic bacteri, Osmotic controlled delivery, Based on the utilization of chitosan gelable properties at acid condition to produce osmotic pressure and its colon specific biodegradation to form in-situ delivery pores for drug reléase, Bioadhesive system, Drug coated with bioadhesive polymer they provide adhesive property at colonic mucosa, Micro particulate carrier system, Based on microparticles which absorb through macrophages present in colon and increase resident time of drug, Dosage Form, Matrices, Compression coated/matrix tablet, Beads, Microparticle, Compression coat, Matrix Tablet, Enteric-coated microsphere, Coating with polymers, Coating with pH sensitive polymers, Coating with biodegradable polymers
