This study aimed to establish an optimization strategy to address delayed tablet disintegration and hardness reduction observed during the scale-up process. Valsartan, a BCS Class II drug with low aqueous solubility, exhibits dissolution and disintegration characteristics that significantly influence its bioavailability. During scale-up process, delayed disintegration led to reduced dissolution, and adjustment of high shear mixer (HSM) process parameters alone showed limited improvement. Consequently, a formulation-based approach was applied by modifying excipient composition in the pre-blending stage. Increasing the proportion of microcrystalline cellulose (MCC 101) while reducing lactose content improved tablet hardness at the same compression force, shortened disintegration time, and enhanced dissolution. Tablets prepared with the optimized composition demonstrated dissolution equivalence with the reference product, achieving a similarity factor (f₂) greater than 50. Furthermore, dissolution equivalence was maintained after hydroxypropyl methylcellulose (HPMC)-based film coating. These results indicate that excipient ratio optimization can effectively resolve disintegration delay and hardness issues during scale-up, providing a foundation for future bioequivalence studies and large-scale manufacturing process development of valsartan tablets.