Formulation and Evaluation of Interpenetrating Polymer Network Microparticles of Diclofenac Sodium

Abstract

Diclofenac sodium, a model anti-inflammatory drug, has adverse effects like gastric irritation and hepatic toxicity. To overcome these problems Interpenetrating Polymer Network microparticles can be used as a controlled drug delivery system. Preparation of Interpenetrating Polymer Network microparticles using two or more polymer is a novel approach as the polymers produce synergistic effect which could increase the mechanical strength and resilience of the microparticles. The aim of the study was to prepare Interpenetrating Polymer Network microparticles of Diclofenac Sodium using chitosan and Ghatti gum which were used to deliver Diclofenac Sodium to the intestine. Microparticles prepared by emulsion-cross-linking method using gluteraldehyde as a cross-linker were characterized by Fourier Transform Infrared Spectroscopy, Differential scanning calorimetry, Scanning electron microscopy and evaluated for in vitro dissolution rate. Fourier Transform Infrared Spectroscopy studies confirmed the absence of chemical interactions between drug, polymers and cross-linking agent. Differential scanning calorimetric results indicated amorphous dispersion of Diclofenac Sodium into Interpenetrating Polymer Network matrix. Scanning electron microscopy pictures showed that microparticles did not agglomerate and had a rough surface. Hydrated surface after swelling showed spongy porous surface which indicated the mechanism of drug release as diffusion. Particle size ranged between 294 to 366 µm. DS percentage encapsulation efficiency ranged from 84.09 to 96.81%. In vitro release studies indicated a dependence of drug release rates on both the amount of CS and GG used in preparation of microparticles. The release was extended up to 12 h and release rates indicated a non-Fickian and super case II mechanism.