Gel Based Formulations in Oral Controlled Release Drug Delivery

Gel-based formulations may be classified as hydrogels, emulgels, and organogels or oleogels. This categorization depends on the polarity of the liquid component present in it. Hydrogels offer excellent potential to be used in oral drug delivery due to inherent biocompatibility, diversity of both natural and synthetic components. In particular, stimuli-responsive hydrogels can meet the physiological changes along the gastro intestinal tract to achieve site-specific, controlled release of protein, peptide and many other molecules for systemic treatment. There are many different techniques for the preparation of different sort of customized hydrogel. In recent years the popularity of oleogels is also in increasing order due to the easy method of preparation and inherent long-term stability of these products to provide the ideal drug delivery matrix. Oleogels are comprised of non-polar dispersion medium like fixed oil, mineral oil, organic solvents which are gelled with organogelator. Most of the studies on oleogels has been conducted on their use in food applications. Hydrogel and oleogel both have good acceptance in the field of oral drug delivery. This review work highlights brief description about both Hydrogels and Oleogels focusing their characteristics, advantages, disadvantages, application, some major techniques of the preparations and modifications of the same in oral drug delivery.