SYNTHESIS AND CHARACTERIZATION OF SITE SPECIFIC SUPERPOROUS HYDROGEL HYBRIDS OF LORATADINE

The aim of present study is to formulate and optimize the site specific controlled release formulation for release of loratadine in upper gastrointestinal tract. Superposrous hydrogel hybrids (SPHH) were prepared by using ferric chloride as crosslinking agent and sodium carboxymethyl cellulose as composite agent. The Superporous Hydrogels were evaluated for swelling ratio, mechanical strength, density, porosity, scanning electron microscopic studies. Statistical software, Design Expert was used for optimization and chosing the final formulation. Loratadine hydrochloride was loaded in optimized formulation and characterized by Fourier Transform Infrared Spectroscopy, X-Ray Diffraction, Differential Scanning Calorimetry and in vitro drug release studies. Superporous Hydrogel Hybrids were prepared with desired mechanical strength and sufficient swelling ratio. Equilibrium Swelling Ratio of hydrogels followed the pattern SPHH < SPHC < CSPH.   The pattern may be attributed to the additional crosslinking and decreased poresize. Reduced swelling ratio may be because of restricted polymeric chain flexibility. H- bonds between poly (AM-co-AA) and NaCMC reduced the polymer ability to form H-bonds with water molecules, limiting water absorption.  Increase in mechanical strength is due to crosslinking with composite agent. FTIR, XRD and DSC studies confirmed the drug integrity in hydrogel polymeric network. Drug release studies showed that initial burst release followed by sustained effect.