Interpenetrating polymer network (IPN) hydrogel microspheres for oral controlled release application

Interpenetrating polymer network (IPN) hydrogel microspheres of sodium carboxymethyl cellulose (NaCMC) and poly(vinyl alcohol) (PVA) were prepared by water-in-oil (w/o) emulsion crosslinking method for oral controlled release delivery of a non-steroidal anti-inflammatory drug, diclofenac sodium (DS). The microspheres were prepared with various ratios of NaCMC to PVA, % drug loading and extent of crosslinking density at a fixed polymer weight. The prepared microspheres with loose and rigid surfaces were evidenced by scanning electron microscope (SEM). Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the IPN formation. Differential scanning calorimetry (DSC) study was performed to understand the dispersion nature of drug after encapsulation. The in vitro drug release study was extensively evaluated depending on the process variables in both acid and alkaline media. All the formulations exhibited satisfactory physicochemical and in vitro release characteristics. Release data indicated a non-Fickian trend of drug release from the formulations. Based on the results of this study suggest that DS loaded IPN microspheres were suitable for oral controlled release application. (C) 2011 Elsevier B.V. All rights reserved.