Parameters SD  of peak area for ropinirole standard % RSD  of peak area for ropinirole  standard 
Mobile phase composition 16.12 0.53
Mobile phase volume 17.23 0.56
Development distance 30.40 1.01
Relative humidity 31.84 1.05
Duration of saturation 22.14 0.73
Activation of prewashed
TLC plates
18.36 0.60
Time from spotting to chromatography 32.45 1.07
Time from chromatography to scanning 41.29 1.37
*each parameter was repeated for six times
Table 2: Robustness of the method*.