Fabrication and optimization of extended-release beads of diclofenac sodium based on Ca++ cross-linked Taro (Colocasia esculenta) stolon polysaccharide and pectin by quality-by-design approach

Abstract

The present investigation was aimed to fabricate and optimize extended-release beads of diclofenac sodium based on an ion-cross-linked matrix of pectin (PTN) and taro (Colocasia esculenta) stolon polysaccharide (TSP) with 23 full factorial design. Total polysaccharide concentration (TPC), polysaccharide ratio (PR), and cross-linker concentration ([CaCl2]) were taken as independent factors with two levels of each. Initially, TSP was extracted, purified, and characterized. Fourier-transform infrared spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) showed drug-polymer compatibility. The study also revealed the significant positive effect of TSP on drug entrapment efficiency (DEE) and sustaining drug release. The response variables (DEE, cumulative % drug-release at 1, 2, 4, 6, and 10 h, release-constant, time for 50 % and 90 % drug release (T50%, T90%), release-similarity factor (f2), and difference factor (f1) were analyzed, and subsequently, independent fabrication variables were numerically optimized by Design-Expert software (Version-13; Stat-Ease Inc., Minneapolis). The optimized batch exhibited appreciable DEE of 88.5 % (± 2.2) and an extended-release profile with significantly higher T50%, T90%, and release-similarity factor (f2) of 4.7 h, 11.4 h, and 71.6, respectively. Therefore, the study exhibited successful incorporation of the novel TSP as a potential alternative adjunct polysaccharide in the pectin-based ion-cross-linked inter-penetrating polymeric network for extended drug release.