Synthesis, characterization and controlled release characteristics of PEGylated hydrogels for diclofenac sodium

In this study, hydrogels of acrylamide with polyethylene glycol methyl ether (poly(AAmco-PEG)) have been prepared by using acrylamide, maleated PEG (MPEG), hydroxyethyl methacrylate (HEMA) and N,N′-methylenebisacrylamide (MBAAm) by redox polymerization in aqueous media. The effect of AAm/MPEG mol ratio, HEMA and MBAAm concentrations on hydrogel swelling has been investigated in water. The co-polymers formed and MPEG were characterized by Fourier transform infrared spectroscopy (FT-IR). Swelling of the hydrogel matrices was evaluated gravimetrically. The method adopted was simple and viable to prepare hydrogels of AAm/PEG to encapsulate diclofenac sodium (DS), an anti-inflammatory drug, without the use of tedious routes like emulsification in oil phase, spray drying, etc. X-ray diffraction (XRD) spectra and scanning electron micrographs (SEM) of the DS-loaded hydrogels have shown the amorphous nature. Microgels of this study were irregular in shape with the average particle size ranging between 157 and 265...