Journal of Pharmaceutical Sciences and Drug Development

Advanced Technologies; Clinical Translation of Colonic Drug Delivery

Mathieu Diniz^{* *}Correspondence: Mathieu Diniz, Editorial Office, Journal of Pharmaceutical Sciences and Drug Development, France, Email:

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Introduction

Targeting drugs directly to the colon is advantageous in the topical treatment of colonic diseases such as ulcerative colitis and Crohn’s disease and has shown potential in gaining the oral delivery of peptides and other labile drugs. A colonic drug delivery system is required to protect a drug during its transit through the upper Gastro-Intestinal (G.I.) tract and allow its release in the colon. Several methods of colonic targeting have been proposed. These include taking advantage of the apparent consistency of small intestinal transit times, the utilization of pH changes within the G.I. tract, and the exploitation of bacterial enzymes localized in the colonic region of the G.I. tract. A system relying on transit time will be dependent on gastric emptying, small intestinal transit, passage across the Ileocecal Junction (ICJ), and factors affecting this transit. Since gastric emptying times and passage across the ICJ have been shown to be extremely variable, site specificity from a timed-release dosage form would be expected to be poor. Original gastrointestinal pH data suggested a progressive increase in pH from the stomach to the rectum. This led to several drugs being coated with pH-dependent polymers to target the colonic region.

More recent G.I. pH measurements have revealed variability and a fall in pH from the ileum to the colon. Detailed and systematic in vitro and in vivo investigations using Eudragit S as a model pH-dependent polymer coat has demonstrated that poor site specificity is gained with this method of targeting. Additional interest in targeting the colon has stemmed from the potential of this region as a site for the entry of drugs into systemic circulation. Compared with the stomach and small intestine, the colon is believed to contain lower levels of luminal and mucosal digestive enzymes. Molecules that are degraded and/or poorly absorbed in the upper gut, such as peptides and proteins, could therefore be bioavailable via the colon. Moreover, drug delivery to the colon could be beneficial when an intentional time delay in absorption is required for the treatment of diseases that are sensitive to circadian rhythms (chronotherapy), such as asthma, angina pectoris, and arthritis. The gastrointestinal tract is essentially a hollow muscular tube, which functions to take in nutrients and eliminate waste by such physiological processes as secretion, motility, digestion, absorption, and excretion. Based on function and morphology, the gastrointestinal tract is divided into the mouth pharynx, esophagus, stomach, small intestine, and large intestine. The large intestine is approximately 1.5 m in length and extends from the ileocecal junction to the anus. It is divided into four sections: caecum, colon, rectum, and anal canal. The colon is further subdivided into ascending, transverse, descending, and sigmoid regions. The colon is involved in the fermentation of polysaccharides and proteins, absorption of water and electrolytes, and the formation, storage, and elimination of fecal material. Focusing on medications and conveyance frameworks to the colonic locale of the gastrointestinal plot has gotten significant interest lately. Logical undertaking in this space has been driven by the need to all the more likely treat neighborhood problems of the colon like provocative gut illness (ulcerative colitis and Crohn's sickness), badtempered gut condition, and carcinoma. The colon is likewise getting critical consideration as a gateway for the passage of medications into the fundamental course. Different conveyance techniques and frameworks have been proposed for colonic focusing. These by and large depend on the abuse of at least one of the accompanying gastrointestinal highlights for their usefulness: pH, travel time, tension, or microflora. Covered frameworks that use the pH differential in the gastrointestinal lot and prodrugs that depend on colonic microbes for discharge have been marketed. Both approaches have their innate impediments. Numerous frameworks being developed have advanced no farther than the seat, while others are costly or complex to produce or miss the mark on wanted siteparticularity. The general polysaccharide frameworks seem, by all accounts, to be the most encouraging because of their common sense and abuse of the most unmistakable property of the colon, plentiful microflora.

Conclusion

The colonic locale of the gastrointestinal lot is an alluring organ for the end goal of focusing on. Focusing on the colon using the oral course offers significant restorative prizes, both regarding neighborhood treatment and foundational treatment. Conveyance frameworks that depend on pH, travel time, strain, or microflora to start discharge in the colon have been proposed. While a portion of these frameworks has arrived at the market, most come up short on the essential characteristics of site particularity. Large numbers of the frameworks right now being developed are either intricate or costly to produce, accordingly restricting their future business potential. Oral for-transformations because of polysaccharides that are helpless to assimilation within the sight of colonic microbes show specific commitment, albeit no such arrangement is financially accessible. In outline, while certain advances have been made around here, much still needs to be finished to understand the clinical capability of colonic medication conveyance completely.