TABLE 3

IC₅₀ values for inhibition of CYP2C8-catalyzed amodiaquine N-deethylation by gemfibrozil analogs and their glucuronide conjugates after incubation with NADPH-fortified HLM for 0 and 30 min

Structure	Substance	Average IC₅₀^{^a}		Ratio: IC₅₀₍₀₎/IC₅₀₍₃₀₎
Structure	Substance	IC₅₀₍₀₎	IC₅₀₍₃₀₎	Ratio: IC₅₀₍₀₎/IC₅₀₍₃₀₎
		μM
	Gemfibrozil	72 ± 7.2	72 ± 6.2	1.0
	Gemfibrozil acyl-β-d-glucuronide	13 ± 2.7	1.0 ± 0.06	13
	BTFM gemfibrozil	13 ± 2.1	17 ± 2.5	0.7
	BTFM gemfibrozil acyl-β-d-glucuronide	37 ± 3.2	43 ± 3.1	<1.0
	o-Me gemfibrozil	>80 (15 ± 7)^{^b}	>80 (14 ± 7)^{^b}	1.0
	o-Me gemfibrozil acyl-β-d-glucuronide	55 ± 6	17 ± 0.3	3.2
	m-Me gemfibrozil	>80 (10 ± 6)^{^b}	>80 (9 ± 5)^{^b}	1.0
	m-Me gemfibrozil acyl-β-d-glucuronide	>120 (29 ± 6)^{^c}	>120 (40 ± 3)^{^c}	>1.0

↵a Data are reported as the mean ± S.D. of n = 4 determinations. IC₅₀₍₀₎ and IC₅₀₍₃₀₎ represent the IC₅₀ determined after 0 and 30 min of incubation with NADPH-fortified HLM.
↵b %inhibition observed at 80 μM ± S.D.
↵c %inhibition observed at 120 μM ± S.D.