Item HCTZ Irbesartan Losartan Telmisartan Valsartan Linear range (µg/ml) 2.5-15 30-180 10-60 16-96 16-96 Detection limit (µg/ml) 0.04 0.14 0.08 0.03 0.04 Quantitation limit (µg/.ml) 0.11 0.44 0.24 0.10 0.11 Regression data           N 5 5 5 5 5 Slope (b) 223.09 122.54 138.95 197.86 33.45 Standard deviation of the slope 1.11 0.26 0.20 0.20 0.20 Intercept (a) 4.00 0.88 9.99 120.99 122.07 Standard deviation of the intercept 3.71 16.4 5.91 8.24 7.14 Correlation coefficient® 0.9999 1.0 1.0 0.9997 1.0 Standard error of regression 9.85 18.46 11.19 125.95 26.75 (Y = a + bC, where C is the concentration of the compound (μg/ml) and Y is the drug peak area)

Table 5: Calibration data was resulted from method validation of Hydrochlorothiazide (HCTZ), Irbesartan, Losartan potassium, Telmisartan and Valsartan respectively.