Hydrogel

ABSTRACTAqua gel is a polymeric gel formulated by using crosslinking agent to form a network of crosslinked polymer chains. It is a hydrophilic structure with capability of holding water in their three-dimensional networks. Formulation and comparative evaluation of Diclofenac aqua gel by using various polymers have been carried out to check efficient concentration of various polymers as well as to choose an appropriate polymer. Diclofenac has chosen as an active pharmaceutical ingredient which have tendency to cause acidity or GI irritation when comes in contact with GI fluid. Avoidance of such side effect is one of the motives of this research. Administration of Diclofenac trans dermally will avoid to get contact with GI fluid as well as avoid GI irritation. In this research various concentration of polymer has been taken to compare between polymer concentration as well as various polymer efficiency.Keywords: Aqua gel, Hydrogel, topical gel, Diclofenac gel, hydrophilic gel.  

The present work aimed to develop a novel chitosan–PVA-based hydrogel sheet which forms an immobilizing matrix for silver nanoparticles (AgNPs). Silver nanoparticles were prepared by chemical reduction method. Silver nitrate was taken as the metal precursor and tri-sodium citrate as a reducing agent. These AgNPs were incorporated in to chitosan-PVA hydrogels in different concentrations (1%, 2%, 4% and 6%) to form F1, F2, F3 and F4 formulations respectively. The prepared chitosan and silver nanoparticle composite hydrogel sheets were characterized using U.V, FTIR, water absorption studies, SEM and Anti-microbial studies. The data shows the average diameter of AgNPs is in the range of 60-70 nm and is roughly spherical in shape. The AgNPs incorporated hydrogel sheets were bactericidal against Escherichia Coli (gram positive) and staphylococcus aureus (gram negative) and it showed good antibacterial effect by disc diffusion method. These results suggested that AgNPs incorporated chitosan hydrogel sheet could be a promising candidate for wound dressing applications.

A pH sensitive hydrogel using Carbopol-PEG 400 combination was prepared and loaded with amoxicillin trihydrate drug to study its sustained release. The hydrogel prepared was of physical nature. Two types of hydrogel were prepared with and without drug. The drug used was amoxicillin trihydrate. This drug is used to treat peptic ulcer in gastrointestinal tract. This drug becomes unstable in acidic environment of stomach. A pH sensitive hydrogel can be designed which can retain the drug in the polymer core at low pH values and release it at high pH value environment like gastrointestinal tract. Characterization of the hydrogel was done by SEM and FTIR and performance was studied by swelling method and in vitro drug release. FTIR studies gave the backbone structure of hydrogel carrying the drug. The surface morphology study by SEM showed that the prepared hydrogel was porous in nature. The swelling studies showed that the hydrogel swelled more in basic medium as the components were anionic in nature. The release profile showed 83.93% sustained drug release after 10hours. The carbopol-PEG400 hydrogel is suitable for the delivery of amoxicillin trihydrate as the drug is not stable in the stomach and can be delivered satisfactorily to the intestine where the pH is favourable.

The nanoparticulate systems are materials having less than 100 nm at least in one dimension. Various nanoparticulate drug delivery systems include biodegradable polymeric nanoparticles, polymeric micelles, solid nanoparticles, lipid-based nanoparticles, nano liposomes, nano hydrogel, magnetic nanoparticles, quantum dots etc. As a family of nanoscale particulate materials, hydrogel nanoparticles (recently referred to as nanogels) have been the points of convergence of considerable amount of efforts devoted to the study of these systems dealing with drug delivery approaches. Interestingly, hydrogel nanoparticulate materials would demonstrate the features and characteristics hydrogels and nanoparticles separately posses, at the same time. Thus, there are many advantages of the nanoparticles including hydrophilicity, flexibility, versatility, high water absorptivity, and biocompatibility. The specific properties which help use of nanogel in medicine, especially dentistry, are the long life span of the drug and the possibility of it being directed to the desired area. Owing to the fact that the concept of nanogels in dentistry is in its infancy, the need arises to disseminate the available information so as to spurt activity in this important area. Here we review the properties, advantages, disadvantages, classification and application of nanogel in dentistry and specifically in periodontics.