Parameters S.D.[peak area) % R.S.D. S.E.
TLC densitometric method Mobile phase composition  0.415 0.021 0.169
Mobile phase volume [± 10%] 0.799 0.040 0.326
Time of saturation [± 10 minutes] 0.225 0.011 0.092
Time from spotting to development [±10 min] 0.309 0.015 0.126
Time from chromatography to scanning [±10 min] 0.319 0.016 0.130
HPLC method Change in organic phase percent in mobile phase [±3.00%] 0.383 0.542 0.156
Change in mobile phase pH [± 0.20] 0.187 0.265 0.076
Change in wavelength of detection [± 2.00] 0.137 0.194 0.056
Change in flow rate [± 0.1] 0.375 0.531 0.153
Change column supplier 0.467 0.661 0.191
Table 4: Robustness of TLC densitometric and HPLC methods [n=6].