Abstract

SUPERPOROUS HYDROGEL (SPH): A NOVEL AND ADVANCED TECHNIQUE OF ORAL CONTROLLED RELEASE DRUG DELIVERY SYSTEM

Manish Keshavlal Ladola*

ABSTRACT

Gastroretentive drug delivery is an approach to prolong gastric residence time, thereby targeting site specific drug release in the upper part of GIT for local or systemic effect. Gastroretentive drug delivery system involves various approaches like: High–density system, bioadhesive system, swelling and expanding system, magnetic system, superporous hydrogel, incorporation of passage delaying food agents, ion exchange resins, bioadhesive liposomal system and floating systems. Superporous hydrogels (SPHs) were developed as novel oral controlled release drug delivery system for those drugs having absorption window in stomach and upper part of gastrointestinal tract (GIT) and to retain drug in the gastric medium. Superporous hydrogels (SPHs) are different from superabsorbent polymers (SAPs) in their very fast swelling property, within minutes, to the equilibrium swollen state regardless of their size. The fast swelling property is based on water absorption through open porous structure by capillary action. The poor mechanical strength of conventional SPHs (CSPHs) was overcome by developing the second-generation SPH composites (SPHCs) and the third-generation SPH hybrids (SPHHs) and superporous hydrogel interpenetrating network (SPHs-IPN). This review includes the differences between SAPs and SPHs, advantages, disadvantages, various generations, methods of preparation, techniques of drug loading, ingredients required for synthesis with their role, methods for synthesis, characterization and applications of SPHs.

Keywords: Superabsorbent polymers, Superporous hydrogels, Mechanical strength, Pore structure, Elasticity.