Quantification of Niacin and Its Metabolite Nicotinuric Acid in Human Plasma by LC-MS/MS: Application to a Clinical Trial of a Fixed Dose Combination Tablet of Niacin Extended-Release/Simvastatin (500 mg/10 mg) in Healthy Chinese Volunteers

Table 1

Precision and accuracy for the analysis of NA and NUA in quality control (QC) samples ( days, 6 replicates per day) in human plasma.

	Concentration (ng/mL)		RSD (%)		Relative; error (%)
	Added	Found	Intraday	Interday
NA	10.0	9.72	6.4	2.8	−2.8
	60.0	61.4	8.7	9.4	2.3
	600.0	587.3	5.0	7.4	−2.2
NUA	10.0	10.3	7.6	5.8	3.2
	60.0	58.2	5.5	5.1	−2.9
	600.0	596.0	5.7	3.7	−0.6