Fabrication and in vitro characterization of HPMC-g-poly(AMPS) hydrogels loaded with loxoprofen sodium

The aim of this study was to prepare hydroxypropyl-methyl cellulose (HPMC)-K15 based hydrogels via free radical polymerization using 2‑acrylamido-2‑methyl propane sulphonic acid (AMPS) as a monomer and N,N′-methylene bisacrylamide (MBAAm) as a crosslinker. Loxoprofen sodium was chosen as a model drug and successfully loaded in hydrogel discs. Sol-gel, porosity, loading efficiency, and the in vitro drug release analysis were carried out to evaluate its drug delivery potential. HMPC-g-poly(AMPS) hydrogels were characterized by using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) approaches. Maximum swelling and drug release were observed at pH 7.4. Kinetic modelling suggested that drug release followed first-order kinetics with the non-Fickian mechanism. FTIR and DSC confirmed the formation of new hydrogels. SEM micrographs confirmed uneven, rough, and partially porous type of surface. These results suggested that HMPC-g-poly(AMPS) hydrogels can be a prospective pH-responsive carrier for delivery of water-soluble drugs, such as loxoprofen sodium.