Table 4.

PPBs and C_u among different in vitro samples grouped by C_p.

Sample Type	Cp (g/L)	Ct (ng/ml)	n	PPB (Mean ± SD%)	p
VRC spiked with human ALB	Total	–	42	42.9 ± 6.3
	30	Total	14	40.0 ± 7.1
		25,000	8	36.8 ± 6.0	0.047
		400	6	44.3 ± 6.6
	40	Total	14	42.8 ± 5.3
		25,000	8	45.5 ± 4.1	0.017
		400	6	39.1 ± 4.6
	50	Total	14	46.0 ± 5.0
		25,000	8	48.7 ± 3.9	0.015
		400	6	42.5 ± 4.3
VRC spiked with human AAG	Total	–	36	46.5 ± 7.6
	0.01	Total	12	38.9 ± 6.0
		25,000	6	37.0 ± 7.7	>0.05
		400	6	40.9 ± 3.3
	0.1	Total	12	47.8 ± 4.0
		25,000	6	45.6 ± 4.0
		400	6	50.0 ± 2.7
	1	Total	12	52.8 ± 5.1
		25,000	6	54.0 ± 3.7
		400	6	51.5 ± 6.3
VRC spiked with human GLB	Total	–	24	37.8 ± 4.1
	10	Total	12	37.4 ± 4.1	>0.05
		25,000	6	35.2 ± 4.3
		1,500	6	39.5 ± 2.7
	30	Total	12	38.3 ± 4.3
		25,000	6	37.2 ± 2.0
		1,500	6	39.3 ± 5.8
VRC spiked with ALB+AAG+GLB	Total	–	24	56.1 ± 4.6
	40.01	Total	12	51.7 ± 4.3
		25,000	6	55.7 ± 0.9	<0.01
		400	6	47.8 ± 1.4
	81	Total	12	57.5 ± 2.6
		25,000	6	59.6 ± 1.6	<0.01
		400	6	55.4 ± 1.5

ALB, albumin; AAG, α1-acid glycoprotein; GLB, globulin; C_p, protein concentration; C_t, total drug concentration; C_u, unbound drug concentration; PPB, plasma protein binding rate