Application of Chitosan in Oral Drug Delivery

Abstract

Oral drug delivery is counted as the preferable route of drug administration due to its convenience, safety, and cost-effectiveness. However, many drugs are not good candidates for oral application mainly because of drug degradation within the gastrointestinal system. Overcoming the obstacles for effective oral delivery of drugs is currently one of the chief goals driving drug delivery research. Recently, remarkable advances in drug delivery technology have led to the increase in the use of various carriers for oral drug delivery. Polymers, as one of the most widely utilized tools, have demonstrated a considerable number of benefits of which stable physicochemical properties and cost-effectiveness are the prominent ones. Along with the mentioned features, an ideal polymeric delivery vehicle should be biocompatible and protect the incorporated drug from enzymatic degradation in the gastrointestinal tract. Chitosan has been extensively studied by many researchers, and a massive data is now available upon its distinctive benefits and restrictions as well as its unique characteristics appreciable for oral drug delivery. It is safe, biocompatible, low cost, and readily available. In addition, intrinsic mucoadhesion ability of chitosan urges its use as an oral drug delivery vehicle. The goal of this chapter is to focus on the application of chitosan as an oral delivery carrier for therapeutic molecules and drugs. Current conventional formulations of chitosan are first reviewed, and the related limitations are investigated to lead readers to the next sections in which novel approaches for improved delivery system are explained as fully as possible. Application of chitosan in oral gene and peptide delivery is explained as separate sections since these two areas have been attracting much attention in recent years due to the intrinsic properties of chitosan making it a promising candidate in the areas. Different strategies employed to improve chitosan polymers regarding physicochemical and targeting properties are covered throughout the script. Diverse modification approaches as well as their limitations are explained, exemplified, and illustrated within the body of the chapter. In the end, the future concept of chitosan oral drug delivery is argued followed by a concise summary.