Application of design of experiments to study the robustness of a HPLC method was carried out, where six factors were selected: the percentage of acetonitrile (ACN) in the mobile phase, the pH of mobile phase, the detector wavelength, the column temperature, the flow rate and the strength of the buffer. These factors are examined in two-level screening experimental designs created using JMP@ (SAS Institute) software. The system suitability parameters like the capacity factor, tailing factor, resolution were calculated and analyzed using the ANOVA method by least squares fitting. The results are within the acceptance criteria showing that the method is robust within the established limits. Forced degradation studies were also conducted for sitagliptin and pioglitazone.