Table 1.

Fraction Unbound (f_u) of 36 TB Drugs and TB-Inactive Compounds^a

	rPlasma fu (%)	rCaseum fu (%)	surrogate fu (%)
Ethambutol	80.2 ± 5.5	35.2 ± 4.4	38.8 ± 5.6
Isoniazid	>99.9	>99.9	>99.9
Acetyl-isoniazid	89.4 ± 4.7	>99.9	>99.9
Pyrazinamide	>99.9	>99.9	62.0 ± 3.5
p-aminosalicylic acid	43.9 ± 1.8	54.7 ± 1.4	51.1 ± 11.2
Ethionamide	29.6 ± 2.5b	52.8 ± 2.4b	27.8 ± 11.9
Rifampicin	6.05 ± 0.2	5.13 ± 0.2	7.3 ± 0.6
Rifapentine	0.59 ± 0.04	0.5 ± 0.1	1.1 ± 0.1
Moxifloxacin	64.5 ± 2.2	13.5 ± 3.7	16.8 ± 1.8
Levofloxacin	44.0 ± 6.0	8.34 ± 0.4	16.3 ± 3.1
Gatifloxacin	65.4 ± 5.1	16.3 ± 4.2	18.8 ± 2.9
Linezolid	56.7 ± 3.1	29.3 ± 3.6	27.9 ± 2.2
Posizolid	8.64 ± 0.9	10.7 ± 1.7	17.6 ± 4.5
Sutezolid	20.5 ± 0.2	30.1 ± 8.7	21.7 ± 1.7
Radezolid	3.05 ± 0.1	5.2 ± 0.8	7.6 ± 1.9
Tedizolid	30.7 ± 2.0	8.8 ± 1.8	13.7 ± 2.7
Clofazimine	<0.01	<0.01	<0.01
Bedaquiline	<0.01	<0.01	<0.01
PA-824	11.1 ± 0.2	7.31 ± 2.2	3.6 ± 0.2
OPC67683	<0.01b	0.04 ± 0.02b	0.02 ± 0.002
LLY001		44.7 ± 3.6	63.2 ± 7.3
LLY002		9.6 ± 0.8	15.3 ± 0.9
LLY003		31.8 ± 4.6	34.0 ± 5.1
LLY004		7.9 ± 0.4	22.8 ± 3.9
LLY005		26.8 ± 1.9	28.1 ± 6.2
LLY006		56.4 ± 6.6	79.05 ± 4.4
LLY007		4.1 ± 0.5	10 ± 2.6
LLY008		1.9 ± 0.1	1.78 ± 0.5
LLY009		3.1 ± 0.3	2.37 ± 0.5
LLY010		0.3 ± 0.04	0.11 ± 0.01
LLY011		0.5 ± 0.1	0.08 ± 0.03
LLY012		0.25 ± 0.04	0.75 ± 0.1
LLY013		0.21 ± 0.05	0.4 ± 0.01
LLY014		0.29 ± 0.05	0.21 ± 0.03
LLY015		9.75 ± 1.23	12.1 ± 3.16
LLY016		13.8 ± 2.8	24.4 ± 2.39

^aCompounds were tested in rabbit plasma (rPlasma), rabbit caseum (rCaseum) and the surrogate matrix produced from human THP1 macrophages. RED assays were conducted in triplicates and f_u is expressed as the mean ± SD.

^bAssays that had <70% recovery.