Evaluation of Hydrophilic Polymers and their Combinations in Formulation of Sustained-Release Matrix Tablets of Water-Soluble Drug

Abstract

Aim of the work: The present study was aimed to investigate matrix-forming property of gum olibanum for sustained-release tablets of tramadol, a freely water-soluble drug. The possible synergistic effect of gum olibanum with hydroxypropyl methylcellulose (HPMC) and xanthan gum, and widely used pharmaceutical excipients on tablet properties was investigated. Methods: Matrix tablets were prepared containing polymers, either alone or in combinations, by wet granulation. Tablets were evaluated for their physico-mechanical properties, drug release and hydration properties. Results: Tablets swelling increased till ~3-4 h this was followed by a decline phase. Drug release from the matrix tablets was dependent on the concentration of gum olibanum. Formulation with drug: gum olibanum in 1:2 released 94.37±2.37% drug in 6 h. The drug release data was analyzed by model dependent and model independent equations. Combination of gum olibanum with HPMC or xanthan gum matrices significantly (p<0.05) modulated drug release, which was reflected by the mean dissolution times (MDTs). Incorporation of lactose induced faster drug release compared to dicalcium phosphate and microcrystalline cellulose. Drug release largely followed first-order kinetics and non-Fickian type of diffusion.