Parameter  D1 method DD1 method MCR method HPLC method **Reported HPLC method
At 290.4 nm At 332 nm At 288.5 nm At 328 nm
Mean 99.9 100.86 100.62 99.88 98.40 100.97 99.78
SD 1.031 0.962 0.455 0.500 1.185 0.509 0.852
n 4 4 4 4 4 4 4
Variance 1.063 0.925 0.207 0.250 1.404 0.259 0.726
Student's t 0.137  (2.45)* 1.284 (2.45)* 1.328 (2.45)* 0.155 (2.45)* 1.44 (2.45)* 1.028 (2.45)*  
F 1.464 (9.2766)*  1.274 (9.2776)* 3.507 (9.2766)* 2.904 (9.2776)*  1.934 (9.2776)* 2.803 (9.2776)*  
* The values in parentheses are the corresponding tabulated values at p=0.05.
** HPLC method (C-18, using acetonitrile: water 38:62 v/v consisting of triethylamine and adjusted to pH 3.6 with 5% O-phosphoric acid, flow rate 0.8 mL min1, 254 nm).
Table 5: Statistical comparison of the results obtained by the proposed methods and the reported HPLC Method [25] for the analysis of OZ in Tibezole® tablets.