Formulation and evaluation of polyelectrolyte complexbased matrix tablet of Isosorbide Mononitrate

Introduction: The polyelectrolyte Complexes (PECs) are based on ionic cross-linking. They have been employed to prepare a sustained release matrix tablets. These systems are based upon the fact that their structure can entrap the drug within them. Isosorbide Mononitrate (ISMN) is an anti-anginal organic nitrate vasodilator used in the treatment of various cardiovascular disorders and prophylaxis of angina Pectoris, which is poorly absorbed from the upper GIT, hence CR formulation is desirable. Materials and Methods: Chitosan (CH)/Sodium alginate (SA), Guar gum (GG), and Xanthan gum (XG) were used as PECs, and were prepared using different proportions i.e., in 1:1 and 1:2 ratio. The optimum ratio of CH: SA, CH: GG and CH: XG was in the ratio was 1:2; these are formed due to electrostatic interaction between oppositely charged poly ions. These normally employ a hydrophilic matrix system. Matrix tablet of ISMN was formulated by using PECs as matrix forming agent by wet granulation technique. Results: The tablets were evaluated for hardness, wt variation, drug content, and in-vitro dissolution studies and found to be within limits. Release kinetics data indicated that ISMN released from the PECs-based matrix tablets of CH-SA, CH-GG and CH-XG CP in 1:1 and 1:2 ratio, followed Fickian and non-Fickian diffusion mechanism respectively. Thus, the drug release rate was extended for over a period of more than 12 h stability studies. There is no signifi cant difference in the mean % drug released from formulation CH-X2 after storing for 3 months at 40°C/75% RH. The FT-IR spectra revealed that there was no interaction between polymers and drug, Statistical analysis showed a signifi cant differences (P < 0.05) for the amount of ISMN released from the formulations (MXG) and formulations (CH-X2). Conclusion: Formulation CH-XG2 (1:2) showed better sustained release of highly water-soluble ISMN with the desired release rate. Thus, the formulated PECs-based matrix tablets seems to be a potential candidate for sustained drug delivery of highly soluble drug ISMN in the symptomatic therapy of angina pectoris.