A sustainable HPLC method coupled with diode array detection for versatile quantification of telmisartan, chlorthalidone and amlodipine in a fixed-dose antihypertensive formulation and dissolution studies

Table 2 Method validation parameters of the proposed HPLC–DAD method for determination of a ternary mixture of Telmisartan, Chlorthalidone and Amlodipine in pure form

Method parameter	TEL	CHT	AML
Range	1.0–140.0 μg/mL	1.0–100.0 μg/mL	1.0–100.0 μg/mL
Regression equations parameters
Slope (b)^a	120.2	52.27	52.73
Intercept (a)^a	50.514	10.289	37.134
Correlation Coefficient (r)	0.9999	0.9999	0.9999
Accuracy^b (Mean ± SD)	100.52 ± 0.62	100.26 ± 1.05	100.09 ± 1.17
Precision
(%RSD)^c	0.65	0.14	0.92
(%RSD)^d	1.50	0.96	1.38
Specificity^e	100.30 ± 0.98	99.87 ± 1.22	100.39 ± 1.11
LOD^f	0.018	0.054	0.094
LOQ^f	0.061	0.177	0.313
Robustness^g	0.85	1.21	0.90

^aRegression equation for HPLC: A = a + bc, where ‘A’ is the average peak area and ‘c’ is the concentration (μg/mL). Six calibration points, each conducted three times
^bMean recovery ± SD for five concentration values in between the calibration points in μg/mL, each conducted three times
^cIntra-day precision [average of three different concentration of three replicates each (n = 9) within the same day], the concentrations were (5.0, 10.0, 40.0 μg/mL) for TEL, (5.0, 12.5, 40 μg/mL) for CHT, and (5.0, 20.0, 40.0 μg/mL) for AML
^dInter-day precision [average of three different concentration of three replicates each (n = 9) repeated on three successive days], the concentrations were the same as in intra-day precision
^e Mean recovery ± SD for determination of the drugs in laboratory prepared mixtures
^fLOD and LOQ were calculated according to signal to noise ratio
^g%RSD for the change in mobile phase ratio (± 2%), flow rate (± 0.1 mL/ min) and buffer pH (± 0.1)

ISSN: 2661-801X