Evaluation of Critical Quality Attributes of Sustained-Release Isosorbide Mononitrate Tablets: An Experimental Study

Abstract

Background: Isosorbide Mononitrate tablets are taken as sustained-release medication and are widely used for the long-term treatment of chronic stable angina, maintaining the benefits of the medicine and reducing the need for frequent doses. Methods: Three brands of sustained-release Isosorbide Mononitrate tablets were evaluated in compliance with USP and IP requirements. The organoleptic properties, weight variations, tablet dimensions, friability, active ingredient content, in vitro dissolution and drug-release kinetics were investigated using common analytical methods. The dissolution data were analyzed using the zero-order and first-order kinetic models, Higuchi model and Korsmeyer–Peppas model. One-way ANOVA was used for statistical evaluation. Result: All formulations met the physical characteristics, weight discrepancy, friability and concentration of the active ingredient standards outlined in the Pharmacopoeia. The tablets had outstanding dimensional stability and strength. In vitro dissolution test showed the dissolution of the drug was regulated in the range of 95.87 – 98.43% after 24 hours. The Higuchi model was the best fit for the drug-release kinetics (R² = 0.991–0.995), and the “Korsmeyer–Peppas model indicated that anomalous (non-Fickian)” diffusion was present (n = 0.50–0.61). For most physical quality characteristics, no significant differences (p > 0.05) were found across the brands. Conclusion: Analysed sustained-release Isosorbide Mononitrate tablets were found to be of pharmaceutical quality and exhibited consistent pharmaceutical quality, drug release and reliable sustained-release properties, demonstrating their pharmaceutical equivalence and therapeutic reliability.