A Liquid Chromatography-Tandem Mass Spectrometry Method for Evaluation of Two Brands of Enalapril 20 mg Tablets in Healthy Human Volunteers

Table 5

Stability of enalaprilat under different storage conditions ().

Storage Condition	QC	Measured QC at	Mean ± SD	Accuracy	Stability
	(ng/ml)	0.0 h (ng/ml)	(ng/ml)	(%)	(%)
Autosampler stability 24 h at 4°C	3			99.19	100.94
	100			95.90	99.93
	160			92.72	102.09
Freeze and thaw stability at −20°C (3 cycles)	3			106.33	95.31
	100			103.29	96.70
	160			103.13	101.18
Room temperature stability for 10 h	3			102.97	98.02
	100			100.29	98.47
	160			97.71	100.17
Accelerated stability at −30.0°C for 30 days	3			102.99	110.47
	100			97.53	103.62
	160			92.25	96.68