Drug name             Recovery ± SD Calculated t- values Calculated F- values Proposed methods Reference method X-tension plus tablets IRB (%) 99.46±1.33 98.98 ±1.10 1.54 1.46 HCTZ (%) 97.77 ±1.02 98.15 ±0.96 2.04 1.13 Losazide tablets LOS (%) 100.35±0.62 100.19±0.45 0.54 1.94 HCTZ (%) 99.88 ±0.31 100.33±0.60 1.31 0.27 Micardis plus tablets TEL (%) 99.90 ±0.16 99.77±0.28 0.71 0.32 HCTZ (%) 99.89 ±0.39 100.02±0.18 0.82 4.74 Disartan co tablets VAL (%) 99.61 ±1.19 99.77 ±1.28 0.20 0.86 HCTZ (%) 100.27±1.94 100.81±1.78 0.41 1.20 (Where the Tabulated t-values and F -ratios at p = 0.05 are 2.57 and 5.05)

Table 8: Statistical comparison of the proposed and published methods for determination of Irbesartan (IRB), Losartan potassium (LOS), Telmisartan (TEL) and Valsartan (VAL) in presence Hydrochlorothiazide (HCTZ) respectively in their dosage forms by reported method (T- student test) and (F –test for variance).