Effect of Sodium alginate in Combination With HPMC K 100 M in Extending the Release of Metoprolol Succinate from its Gastro-Retentive Floating Tablets

Abstract

Abstract: Aim of work: The aim of present study was to convert Metoprolol Succinate (MS) into Gastro Retentive Floating Tablet (GRFT) and simultaneously to determine the effect of Sodium Alginate (SA) in combination with HPMC K 100M in extending the release of MS. Method: The drug- excipients compatibility studies of MS and the polymers were carried by FTIR studies. The effervescent GRFT of MS was prepared by non aqueous wet granulation. All Formulations were evaluated for pre-compression, post-compression, in vitro buoyancy and accelerated stability studies: for the best formulation for 3 months. Results: The drug- excipients compatibility studies reveals that MS and the polymers used are compatible. Evaluation parameters were within the acceptable limits for all formulations. In-vitro dissolution studies, showed the formulation F4 having the combination of 20% HPMC K100M and 10% SA is exhibiting better extended release up to 12 h, with a Floating Lag Time (FLT) of 20 s, Total Floating Time (TFT) and Matrix Integrity (MI) maintained up to 12 h than other formulations. Regression Coefficients of Zero order and Higuchi equations suggested the drug release follows Zero order and is predominantly by diffusion respectively. The Diffusion exponent (n) of Korsmeyer-Peppas model suggested the release mechanism is by non- Fickian transport. DSC studies further confirmed the drug is in the same state even in the optimized formulation F4 with out interacting with the polymers and excipients in the formulation. Accelerated stability studies indicate no significant differences in the optimized formulation F4. Conclusion: In conclusion, by optimizing the right ratios of the release-retarding gel-forming polymers HPMC K100M and SA, GRFT of MS with a better extended release up to 12 h was formulated. Key words: Gastro retentive floating tablets (GRFT), HPMC K100M, In vitro buoyancy studies, Metoprolol Succinate (MS), Sodium alginate.