Table 2: Experimental design matrix (23) for robustness test.

Experiment no. Acetaminophen content ( ) mg · tablet−1 in tabletsa
P1P2P3

1+++++++499.0494.5501.2
2+++454.2451.6459.8
3+++496.4494.1496.7
4+++485.1481.4488.2
5+++501.1501.3503.4
6+++495.8491.5492.5
7+++478.0477.9485.6
8+++485.9477.2483.5

Effect of the drug
 P1−6.5251.17513.375−15.32511.67514.6755.075
 P2−6.5792.07816.521−16.7779.80411.2975.278
 P3−4.7750.72515.725−12.67510.4259.2256.025

Product 1 (P1), Product 2 (P2), Product 3 (P3).