Hydrogel as a Drug Delivery System

Abstract

Hydrogels are hydrophilic three-dimensional, polymeric networks system. Hydrogel are hydrophilic system and capable of absorbing large amounts of aqueous solvent. It behaves like a semisolid system and generally follow non-Newtonian property. Hydrogel provide easy application, good spreadibility, non-grease, non-staining properly etc. Moreover, hydrogels can be converted to variety of forms apart depending upon the requirement including Newtonian and non-Newtonian slabs, microparticles, nanoparticles, topical gel, films etc. Hydrogels are commonly used as dosages form and protective materials. Hydrogels are equally useful for diagnostic and cosmetic purpose. In last two decades, the mucoadhesive or bio-adhesive and biodegradable properties of hydrogels  is advantageous in immobilizing the drug at the site of application. Most common hydrogel are obtained from cellulose polymer, acacia, tragacanth, acrylate polymers, eudragit polymers etc. Method of preparation and evaluation of hydrogel is also easy and economic as they do not require any specific and costly equipment. Hydrogels are also useful in making targeted and novel drug delivery system. They also offer unique opportunity for the dispensing of various drug available in the form of nanoparticles, liposomes, nanosomes, microparticles, solid lipid particles. Hydrogel provide opportunity for the delivery of drug in solution form or base for various dosages forms. Hydrogel is compatible for variety of drugs and skin, more over it is non-irritant, non-greasy and non-staining.  Development, formulation and evaluation of hydrogel is also easy. Pharmaceutical technique offers to design a desired three-dimensional structure like thixotropic, dialatent, Newtonian, non-Newtonian and other property. Study of mechanism of drug release and release kinetics can be studies using usual method of mathematic modelling.