Development and Validation of Spectrophotometric Methods for Simultaneous Estimation of Valsartan and Hydrochlorothiazide in Tablet Dosage Form

Table 5

Summary of validation parameters.

Methods	Method 1		Method 2
	VAL	HCT	VAL	HCT
𝜆max	249.4 nm	272.6 nm	258.4 nm	272.6 nm
Linearity range (𝜇g/mL)	12.8–76.8	2–12	12.8–76.8	2–12
Regression equation	𝑌=0.150𝑥+0.081	𝑌=0.181𝑥+0.079	𝑌=0.0269𝑋+0.064	𝑌=0.0542𝑋+0.013
Slope (m)	0.150	0.181	0.0269	0.0542
𝑌 – intercept (𝑐)	0.081	0.079	0.064	0.013
Correlation coefficient (𝑟^2)	0.998	0.998	0.999	0.999
% recovery (𝑛=3)	100.20	100.19	100.40	100.20
LOD (𝜇g/mL)	1.60	0.37	1.60	0.32
LOQ (𝜇g/mL)	4.87	1.12	4.86	0.97
Molar absorptivity (lit/mole/cm)	14894.78	16613.89	12242.19	16643.66
Sandell’s sensitivity (𝜇g/sqcm/0.001)	0.02924	0.01793	0.03558	0.01789
Standard error	1.196×10^−3	2.468×10^−3	0.8381×10^−3	2.8324×10^−3
Precision (% RSD)
Intra- day (𝑛=3)	0.334	1.361	1.143	1.044
Inter-day (𝑛=3)	0.931	1.402	0.920	1.210
Specificity (% RSD)
Addition of MCC	1.6	1.8	0.9	1.2
Addition of starch	0.5	0.8	0.3	0.7
Ruggedness (% RSD)
Analyst I (𝑛=3)	0.5	0.6	0.2	0.5
Analyst II (𝑛=3)	1.2	1.1	1.1	0.9
Robustness (% RSD)
0.2 N NaOH (𝑛=3)	0.8	1.2	1.6	1.5
0.5 N NaOH (𝑛=3)	0.5	1.3	0.8	1.2