Indian Journal of Science and Technology

Abstract

Objectives: We aimed to formulate and optimize bilayer tablets of metoprolol tartrate consisting of both immediate and sustained release layer. Methods: A 2³ factorial design was employed in formulating the GFDDS in which parameters, such as amount of HPMC (X₁), sodium bicarbonate + citric acid (X₂), and crospovidone (X₃) were characterized as independent variables, whereas percent metoprolol release at 30 min (Y₁), 4 hr (Y₂), 8 hr (Y₃), floating lag time (Y₄), and total floating time (Y₅) were considered as dependent variables. Findings: The formulations showed the biphasic release of metoprolol, where the immediate layer was completely disintegrated within 30 min and the release of the sustained layer was extended to 8 hr. Prompt disintegration of the immediate layer was facilitated by the combined effects of sodium starch glycolate and sodium bicarbonate + citric acid, whereas the extended release was assisted by HPMC. Formulations, where HPMC played the major role, were considered the best formulations. A good correlation was displayed between the experimental and predicted values that confirm the practicability of the model. Application/improvements: This study shows the effect of various variables in the release of metoprolol tartrate and formulates the bilayer tablets of metoprolol tartrate for the immediate and sustained drug release.
Keywords: Metoprolol, Floating Drug Delivery System, Bilayer, Immediate Release Layer, Sustained Release Layer