Diabetes mellitus is a chronic disease with high and growing prevalence worldwide. Therefore, the development of fast and efficient methods for the QC of antidiabetic drugs is of fundamental importance. Two ultra-fast methods, using a conventional (C18 100 × 2.1 mm, 5 μm fully porous particle) column or a fused-core (C18 100 × 2.1 mm, 2.7 μm fused-core particle) column, were developed for the simultaneous determination of four antidiabetic drugs (chlorpropamide, glibenclamide, gliclazide, and glimepiride). The developed methods were compared in terms of efficiency, speed of analysis, resolution, and peak symmetry. Both methods were validated with respect to selectivity, system suitability, linearity, precision, accuracy, LOD, LOQ, and robustness, using glibenclamide as model. Conventional and fused-core methods were shown to be appropriate for the determination of glibenclamide in tablets; however, the fused-core column presented higher efficiency, detectability, and resolution. Also, it enabled faster analysis, with separation of the four drugs in less than 1 min.