Parameters Flow  Rate PH Acetonitrile % Wavelength
Value 1.1 1.3 5.2 5.8 33 37 238 242
Amlodipine Besylate 4.9 4.53 4.42 5.26 8.39 3.37 5.45 5.43
Amlodipine impurity A 6.29 5.86 8.87 3.94 6.93 3.34 4.96 4.92
Atorvastatin impurity A 13.99 13.35 16.7 11.07 16.12 11.03 13.56 13.51
Atorvastatin Calcium 4.61 4.48 5.15 4.25 5.39 3.86 4.61 4.62
Atorvastatin impurity C 2.77 2.69 2.92 2.82 3.41 2.33 2.87 2.87
Amlodipine impurity B 8.97 8.6 14.83 14.37 9.66 12.22 11.29 11.25
Table 4: Effect of Changes of Some Parameters on Resolution during Method Robustness.