Table 4.

Stability of belinostat and metabolites under varying conditions.

Storage condition	Concentration (ng/mL)		Stability (%)	CV (%)	Replicates
Belinostat
Stock solution 6 h
Ambient temp.		1,000	102.1	9.5	6
Stock solution 10 months −80 °C
		1,000	100.6	10.4	6
Plasma 4 h
Ambient temp.	QCLL	30	97.8	9.3	4
	QCL	100	102.1	6.4	4
	QCM	2500	98.6	5.3	4
	QCH	4000	103	4.5	4
Plasma 3 freeze-thaw cycles −80 °C
	QCLL	30	98.2	6.5	6
	QCL	100	95.0	5.2	6
	QCM	2500	99.6	4.1	6
	QCH	4000	97.9	3.3	6
Plasma 9 months −80 °C
	QCLL	30	90.3	9.7	6
	QCL	100	86.4	9.3	6
	QCM	2500	88.2	5.2	6
	QCH	4000	91.1	7.6	6
Belinostat-glucuronide
Stock solution 6 h					6
Ambient temp.		1,000	96.1	9.3
Stock solution 10 months −80 °C					6
		1,000	106.7	4.1
Plasma 4 h					4
Ambient temp.	QCLL	30	98.3	11.1	4
	QCL	100	113.8	10.7	4
	QCM	2500	102.9	9.6	4
	QCH	4000	101.6	9.7
Plasma 3 freeze-thaw cycles −80 °C					6
	QCLL	30	93.1	9.4	6
	QCL	100	106.3	14.8	6
	QCM	2500	97.4	10.6	6
	QCH	4000	100.1	8.9
Plasma 9 months −80 °C					6
	QCLL	30	91.5	11.6	6
	QCL	100	95.7	11.4	6
	QCM	2500	100.7	8.7	6
	QCH	4000	97.7	8.1	6
Methyl-belinostat
Stock solution 6 h					6
Ambient temp.		1,000	95.6	9.0
Stock solution 7 months −80 °C					6
		1,000	104.0	9.4
Plasma 4 h					4
Ambient temp.	QCLL	30	99.6	10.9	4
	QCL	100	110.0	6.3	4
	QCM	2500	99.3	7.0	4
	QCH	4000	101.2	7.8
Plasma 3 freeze-thaw cycles −80 °C					6
	QCLL	30	99.3	11.4	6
	QCL	100	104.4	6.8	6
	QCM	2500	95.2	8.4	6
	QCH	4000	99.1	6.5
Plasma 9 months −80 °C					6
	QCLL	30	88.0	5.3	6
	QCL	100	93.4	10.8	6
	QCM	2500	100.2	6.0	6
	QCH	4000	96.0	4.8	6
M21
Stock solution 6 h
Ambient temp.		1,000	105.9	13.7	6
Stock solution 10 months −80 °C
		1,000	104.3	11.6	6
Plasma 4 h
Ambient temp.	QCLL	30	119.3	8.8	4
	QCL	100	104.6	13.2	4
	QCM	2500	104.0	10.8	4
	QCH	4000	95.3	8.5	4
Plasma 3 freeze-thaw cycles −80 °C
	QCLL	30	109.6	11.7	6
	QCL	100	106.6	8.4	6
	QCM	2500	106	8.5	6
	QCH	4000	103.2	11.0	6
Plasma 9 months −80 °C
	QCLL	30	95.3	12.7	6
	QCL	100	86.4	12.5	6
	QCM	2500	87.4	6.5	6
	QCH	4000	91.0	12.4	6
M24
Stock solution 6 h
Ambient temp.		1,000	103.8	9.5	6
Stock solution 10 months −80 °C
		1,000	104.5	9.7	6
Plasma 4 h
Ambient temp.	QCLL	30	106.3	13.0	4
	QCL	100	122.2	10.3	4
	QCM	2500	104.7	10.4	4
	QCH	4000	99.3	14.6	4
Plasma 3 freeze-thaw cycles −80 °C
	QCLL	30	92.2	10.1	6
	QCL	100	115.6	8.5	6
	QCM	2500	101.6	12.6	6
	QCH	4000	97.6	14.9	6
Plasma 9 months −80 °C
	QCLL	30	98.1	10.6	6
	QCL	100	96.5	10.5	6
	QCM	2500	101.3	9.0	6
	QCH	4000	100.7	12.2	6
M26
Stock solution 6 h
Ambient temp.		1,000	99.8	5.9	6
Stock solution 7 months −80 °C
		1,000	115.8	2.3	6
Plasma 4 h
Ambient temp.	QCLL	30	105.3	14.0	4
	QCL	100	107.6	13.1	4
	QCM	2500	106.7	13.4	4
	QCH	4000	100.3	12.1	4
Plasma 3 freeze-thaw cycles −80 °C
	QCLL	30	93.2	12.0	6
	QCL	100	103.8	14.6	6
	QCM	2500	103.1	10.5	6
	QCH	4000	100.8	12.1	6
Plasma 9 months −80 °C
	QCLL	30	100.5	11.8	6
	QCL	100	96.1	14.3	6
	QCM	2500	100.8	9.1	6
	QCH	4000	95.6	11.6	6