## 3 Results and Discussion
### Method Validation
#### 3.2.5 Method Robustness
\begin{table}
\begin{tabular}{c|c c c|c c c c c c c c} \hline \hline  & \multicolumn{3}{c|}{**Retention Time**} & \multicolumn{3}{c}{**Tailing Factor**} & \multicolumn{3}{c}{**Tinetical Plates**} & \multicolumn{3}{c}{**Resolution**} & **Resolution** \\ \cline{2-11}  & **M** & **Gp** & **Gc** & **Mt** & **Gp** & **Gc** & **Mt** & **Gp** & **Gc** & **Mt** & **Gp** & **Gc** & **Between Mt** & **Between Cp** \\  & & & & & & & & & & & & **and GP Graphs** & **and GC Paths** & **and GC Paths** \\ \hline Condition.1 & 1.004 & 3.145 & 4.867 & 1.208 & 1.083 & 1.117 & 1427 & 2903 & 3690 & 7.078 & 6.216 \\ Mobile plane & 1.007 & 3.148 & 4.862 & 1.203 & 1.081 & 1.12 & 1425 & 2915 & 3716 & 7.119 & 6.209 \\ composite A5 ratio & 4.752 & 1.029 & 3.147 & 4.86 & 1.202 & 1.081 & 1.124 & 1880 & 2916 & 3697 & 7.114 & 6.198 \\ \hline Mean & 1.002 & 3.147 & 4.863 & 1.204 & 1.082 & 1.120 & 1427.333 & 2911.333 & 3071.000 & 7.104 & 6.208 \\ \hline SD & 0.002 & 0.002 & 0.004 & 0.003 & 0.001 & 0.004 & 2.517 & 7.224 & 13.454 & 0.022 & 0.009 \\ \hline \(\times\) RSD & 0.001 & 0.000 & 0.001 & 0.003 & 0.001 & 0.003 & 0.002 & 0.002 & 0.004 & 0.003 & 0.001 \\ Condition.2 & 1.002 & 2.647 & 3.804 & 1.202 & 1.076 & 1.086 & 1410 & 2611 & 3419 & 5.095 & 4.95 \\ Mobile phase & 1.665 & 2.648 & 3.805 & 1.205 & 1.075 & 1.096 & 1414 & 2620 & 3458 & 5.123 & 4.967 \\ composition.A8 ratio & 1.071 & 2.631 & 3.807 & -1.204 & 1.075 & 1.089 & 1421 & 2632 & 3452 & 5.106 & 4.961 \\ \hline Mean & 1.668 & 2.649 & 3.805 & 1.204 & 1.075 & 1.090 & 1415.000 & 2621.000 & 3443.000 & 5.108 & 4.959 \\ SD & 0.003 & 0.002 & 0.002 & 0.002 & 0.001 & 0.005 & 5.568 & 10.536 & 2.1000 & 0.014 & 0.009 \\ \hline \(\times\) RSD & 0.002 & 0.001 & 0.000 & 0.001 & 0.001 & 0.005 & 0.004 & 0.004 & 0.006 & 0.003 & 0.002 \\ \hline \(\times\) RSD & 1.802 & 2.885 & 3.544 & 1.208 & 1.089 & 1.119 & 1281 & 2468 & 3290 & 5.638 & 5.277 \\ \hline Condition.3 & 1.399 & 2.282 & 3.554 & 1.207 & 1.084 & 1.115 & 1283 & 2471 & 3265 & 5.648 & 5.248 \\ Row rate 1.2 mL/min & 1.398 & 2.374 & 3.521 & 1.203 & 1.089 & 1.123 & 1280 & 2445 & 3244 & 5.604 & 5.222 \\ \hline Mean & 1.400 & 2.800 & 3.553 & 1.206 & 1.087 & 1.119 & 1283.333 & 2643.333 & 3266.333 & 5.630 & 5.249 \\ \hline SD & 0.002 & 0.006 & 0.012 & 0.003 & 0.003 & 0.004 & 1.528 & 14.224 & 23.079 & 0.023 & 0.028 \\ \hline \(\times\) RSD & 0.001 & 0.002 & 0.003 & 0.002 & 0.003 & 0.004 & 0.001 & 0.006 & 0.007 & 0.004 & 0.005 \\ \hline \(\times\) RSD & 2.084 & 3.366 & 5.533 & 1.195 & 1.074 & 1.121 & 1.974 & 3015 & 3831 & 6.375 & 5.823 \\ Condition.4 & 2.08 & 3.993 & 5.37 & 1.206 & 1.073 & 1.12 & 1570 & 3012 & 3826 & 6.41 & 5.836 \\ Row rate 0.8 mL/min & 2.08 & 3.996 & 5.379 & 1.199 & 1.073 & 1.121 & 1571 & 3009 & 3814 & 6.419 & 5.841 \\ \hline Mean & 2.081 & 3.992 & 5.857 & 1.200 & 1.073 & 1.121 & 1571.667 & 3012.000 & 3823.647 & 6.401 & 5.833 \\ \hline SD & 0.002 & 0.005 & 0.013 & 0.006 & 0.001 & 0.001 & 2.002 & 3.000 & 8.757 & 0.023 & 0.009 \\ \hline \(\times\) RSD & 0.001 & 0.001 & 0.002 & 0.005 & 0.001 & 0.001 & 0.001 & 0.001 & 0.002 & 0.004 & 0.002 \\ \hline \end{tabular}
\end{table} 
Table 5: Robustness results showing the chromatographic parameters of metforminin (Mt), glipizide (CP) and glizzide (Gc) following the changes made to the pH of the mobile phase, changes made to the ratio of the mobile phase components (A and B) and the flow rate of the chromatographic run. \begin{table}
\begin{tabular}{|c|c|c|c|c|c|c|c|c|c|c|c|} \hline  & \multicolumn{2}{c|}{**Retention Time**} & \multicolumn{4}{c|}{**Tailing Factor**} & \multicolumn{4}{c|}{**Theoretical Plates**} & \multicolumn{1}{c|}{**Resolution**} \\ \cline{2-13}  & **Mr** & **Gp** & **Gc** & **Mt** & **Cp** & **Gc** & **Mt** & **Gp** & **Gc** & **Mt** & **Gp** & **Gc** & **Requation