Metformin is a first-line oral antihyperglycemic agent widely prescribed for managing type 2 diabetes mellitus (T2DM), due to its proven safety, efficacy, and cost-effectiveness. This research article provides a comprehensive review of essential pre-formulation studies for developing an optimized metformin tablet. Key parameters such as solubility, polymorphism, particle size distribution, pH-dependent stability, hygroscopic nature, and excipient compatibility are evaluated to support robust formulation, improved bioavailability, and consistent therapeutic outcomes. These studies also inform manufacturing and storage decisions. Additionally, the article presents a comparative analysis of commonly used antidiabetic drugs—including sulfonylureas, DPP-4 inhibitors, SGLT2 inhibitors, thiazolidinediones, GLP-1 receptor agonists, and insulin therapies—based on their mechanisms, efficacy, side effects, cardiovascular benefits, cost, and patient adherence. Data were gathered from literature and clinical surveys across hospitals and pharmacies. Findings reaffirm metformin’s central role in T2DM treatment while highlighting the importance of alternative or combination therapies when needed. The study emphasizes the value of pre-formulation and comparative drug profiling in optimizing personalized treatment strategies and enhancing patient outcomes.