Significance of Hydrophobic Polymer in Novel Drug Delivery System

Polymers, due to their diverse topology and chemistry, account for a significant portion of the materials used in controlled release formulations and drug-targeting systems. They have played an integral role in the advancement of drug delivery technology by providing controlled release of therapeutic agents in constant doses over long periods, cyclic dosage, and tunable release of both hydrophilic and hydrophobic drugs. Eudragit is the brand name for a diverse range of polymethacrylate-based copolymers. It includes anionic, cationic, and neutral copolymers based on methacrylic acid and methacrylic/acrylic esters or their derivatives. Eudragits are amorphous polymers having glass transition temperatures between 9 to > 150o C. Eudragits are non-biodegradable, nonabsorbable, and nontoxic. Anionic Eudragit L dissolves at pH > 6 and is used for enteric coating, while Eudragit S, soluble at pH > 7 is used for colon targeting. In this review, the physicochemical characteristics and applications of different grades of Eudragit in colon-specific/enteric-coated/ sustained release drug delivery and taste masking have been addressed.