Item Irbesartan Losartan Telmisartan Valsartan
Linear range (μl/ml) 30-180 10-60 16-96 16-96
Detection limit (μg/ml) 0.007 0.06 0.01 0.13
Quantitation limit (μg/ml) 0.02 0.185 0.04 0.4
Regression data        
N 5 5 5 5
Slope (b) 116.98 133.95 193.23 113.1
Standard deviation of the slope 0.06 0.02 0.22 0.15
Intercept (a) 198.08 68.64 550.82 222.26
Standard deviation of the intercept 13.64 3.97 11.97 9.28
Correlation coefficient (r) 1.0 1.0 0.9997 0.9998
Standard error of regression 40.1 15.25 118 55.12
Table 5: Calibration data for analysis of the mixture by use of the proposed HPLC method of Irbesartan, Losartan potassium, Telmisartan and Valsartan respectively