Development and Validation of Stability-Indicating Method for Estimation of Chlorthalidone in Bulk and Tablets with the Use of Experimental Design in Forced Degradation Experiments

Table 1

Experimental matrix of 2³ factorial design for acid and alkali degradation.

Expt. number

Levels of factor in experiment

Interaction

Total

⁢%; ⁢acid deg.

⁢%; alkali deg.

1

−1

−1

−1

+1

+1

+1

−1

+1

7.14

5.43

2

+1

−1

−1

−1

+1

−1

+1

+1

5.03

7.66

3

−1

+1

−1

−1

−1

+1

+1

+1

22.61

25.43

4

+1

+1

−1

+1

−1

−1

−1

+1

20.27

27.69

5

−1

−1

+1

+1

−1

−1

+1

+1

10.00

11.69

6

+1

−1

+1

−1

−1

+1

−1

+1

10.07

10.25

7

−1

+1

+1

−1

+1

−1

−1

+1

36.23

32.51

8

+1

+1

+1

+1

+1

+1

+1

+1

35.24

36.42

+1 indicates the high level for each factor and −1 indicates the low level for each factor.