Simultaneous Determination of Amlodipine, Hydrochlorothiazide, and Valsartan in Pharmaceutical Products by a Combination of Full Spectrum Measurement and Kalman Filter Algorithm

Table 6

Method repeatability.

	Mixture	AML			HYD			VAL
		Rep 1	Rep 2	Rep 3	Rep 1	Rep 2	Rep 3	Rep 1	Rep 2	Rep 3
H1	C (µg/mL)	0.253	0.252	0.254	0.320	0.320	0.321	3.990	3.980	4.010
	Cmean (µg/mL)	0.253			0.320			3.993
	RSDmea (%)	0.4			0.3			0.4
	1/2 RSDHorwitz (%)	9.9			9.5			6.5
H2	C (µg/mL)	0.511	0.510	0.514	0.646	0.645	0.650	8.060	8.044	8.109
	Cmean (µg/mL)	0.5120			0.647			8.071
	RSDmea (%)	0.4			0.5			0.4
	1/2 RSDHorwitz (%)	6.3			8.6			5.9
H3	C (µg/mL)	1.016	1.013	1.020	1.290	1.286	1.296	16.050	15.994	16.114
	Cmean (µg/mL)	1.016			1.291			16.053
	RSDmea (%)	0.4			0.4			0.4
	1/2 RSDHorwitz (%)	8.0			7.7			5.3
H4	C (µg/mL)	4.981	4.971	5.008	5.064	5.054	5.089	4.821	4.811	4.844
	Cmean (µg/mL)	4.987			5.069			4.825
	RSDmea (%)	0.4			0.4			0.4
	1/2 RSDHorwitz (%)	6.3			6.3			6.3

RSD_mea: RSD calculated from standard mixture measurement.