Background: Anti-reflux formulation is one of the popular formulations across the globe in the pharmaceutical industry used specifically for the management of gastro-oesophageal reflux disease. But, this formulation is less explored with respect to research. Anti-reflux formulation has challenges to show its antacid functionality, which could have synergies in the management of re-fluxes in gastro-oesophageal reflux disease. Alkalizing agents act as antacid and improve the acid neutralization capacity in the anti-reflux formulation, and can be used appropriately as they affect raft strength beyond certain (optimum) limits. Objective: The objective of this work is to investigate the significance of alkalizing agent in sodium alginate based on oral liquid anti-reflux suspension for the management of Gastro-oesophageal Reflux Disease (GERD). Methods: In the present study, the formulation was prepared using sodium alginate along with different alkalizing agents like calcium carbonate and sodium bicarbonate at different levels. The formulation was further studied for in-vitro characterization like pH, viscosity, Acid Neutralization Capacity (ANC), thickness, formation speed, flotation, and raft strength. Results: The formulation with a higher level of calcium carbonate as the alkalizing agent showed a positive effect on the acid neutralization capacity (20.83mEq) and raft strength (16.95g) as well. Whereas, the formulation with a higher level of sodium bi-carbonate (4.01%) showed improved acid neutralization (22.31mEq) but showed a negative effect on raft strengths (10.08g). Conclusion: Based on the study, the optimum levels include 5% sodium alginate, 1.6% calcium carbonate and 2.67% sodium bicarbonate to achieve good liquid suspension formulation possessing good acid neutralization capacity as well as raft strength. © 2020 Bentham Science Publishers.