Development and Validation of a Chromatography Method Using Tandem UV/Charged Aerosol Detector for Simultaneous Determination of Amlodipine Besylate and Olmesartan Medoxomil: Application to Drug-Excipient Compatibility Study

Table 3

Robustness study for AMLO and OLME determined by HPLC-DAD and HPLC-CAD.

Chromatographic condition	AMLO				OLME
	DAD		CAD		DAD		CAD
	Concentration (μg mL^−1)	(min)	Concentration (μg mL^−1)	(min)	Concentration (μg mL^−1)	(min)	Concentration (μg mL^−1)	(min)
Original method	176.4 ± 0.1	7.854	176.3 ± 0.1	7.926	300.3 ± 0.1	4.336	299.8 ± 0.1	3.987
Mobile phase: acetonitrile 62%	164.7 ± 0.1	7.556	165.3 ± 0.1	7.976	288.8 ± 0.1	4.327	287.5 ± 0.1	4.76
Mobile phase: acetonitrile 58%	165.5 ± 0.1	7.921	166.1 ± 0.1	8.341	309.2 ± 0.1	4.406	310.4 ± 0.1	4.755
Flow rate: 0.4 mL min^−1	172.5 ± 0.1	8.291	171.4 ± 0.1	8.711	295.9 ± 0.1	4.512	294.7 ± 0.1	4.860
Flow rate: 0.6 mL min^−1	173.1 ± 0.1	7.125	174.5 ± 0.1	7.545	298.2 ± 0.1	4.154	299.4 ± 0.1	4.500
Column temperature: 30°C	187.4 ± 0.1	7.601	188.6 ± 0.1	8.022	284.6 ± 0.1	4.391	285.4 ± 0.1	4.742
Column temperature: 20°C	181.3 ± 0.1	8.095	180.2 ± 0.1	8.514	280.1 ± 0.1	4.395	279.3 ± 0.1	4.745

: retention time.