Herbal remedies serve a vital role in developing therapeutic agents due to their proven effectiveness in treating various ailments. However, identifying active compounds from plant sources presents significant challenges in herbal medicine research. Authenticating these compounds and studying interactions between different herbs, in addition to between herbs and drugs, especially in polypharmacy, are crucial steps. This leads to the re-evaluation and enhancement of agents for improved efficacy and reduced side effects, promoting the development of safer drugs for different disorders. This study employed a 2² factorial design to optimize a polyherbal suspension formulation using Bael (Aegle marmelos) and Bay (Cinnamomum tamala) leaves. This design enabled the exploration of interactions between two key factors: the concentrations of sodium CMC and Tween 20. The study assessed phytochemical properties, sedimentation volume, redispersibility, rheology, viscosity, pH, and crystal growth. Based on optimisation results batch 2 was considered to be optimised batch, demonstrating excellent stability, redispersibility, appropriate viscosity, and stable physicochemical properties. This study underscores the importance of using suitable excipients to enhance the stability of herbal formulations, offering a model for future herbal product development. Key words: Polyherbal, Suspension, Factorial Design, Optimization