Spectrophotometric Method for Determination of Five 1,4-Dihydropyridine Drugs Using N-Bromosuccinimide and Indigo Carmine Dye

Table 4

Ruggedness studies for NBS/INC method.

Drugs^b	Recovery% ± SD^a
	Instrument		Interday variation
	Shimadzu	Jenway	Day 1	Day 2	Day 3
NIF	99.72±0.85	98.90±0.64	100.10±0.85	100.31±0.68	99.51±1.30
NIC	100.31±0.78	99.37±0.69	98.51±0.82	99.20±1.02	99.74±0.65
NIM	101.81±0.82	100.62±1.15	100.20±1.06	99.80±0.75	100.26±0.60
FEL	99.40±0.96	100.21±1.18	101.50±0.51	100.42±1.40	99.80±1.04
AML	100.30±1.32	99.80±0.76	99.52±0.97	100.68±0.59	99.60±1.15

aMean of three determinations.
^bConcentration of the drugs is 10.0 μg/mL.