TABLE 1.

Permeability (P_app, 10⁻⁶ cm·s⁻¹) for the six FQs in the absence and presence of PSC-833

Drug	Log D	In the absence of PSC-833 (total Papp)			In the presence of PSC-833 (passive Papp)			PSC-833-sensitive (active Papp) differenceb		% of active contribution (BL-AP secretory)
		AP-BL absorptive	BL-AP secretorya	Efflux ratio	AP-BL absorptive	BL-AP secretory	Efflux ratio	AP-BL absorptive	BL-AP secretory
CIP	−0.93	0.7 ± 0.02	2.7 ± 0.07**	4	0.8 ± 0.03	0.7 ± 0.01	0.9	0.1	2.0	73
NOR	−1.16	0.6 ± 0.05	2.0 ± 0.04*	3.3	0.7 ± 0.03	0.6 ± 0.01	0.8	0.1	1.4	70
LVX	−0.41	2.4 ± 0.10	6.2 ± 0.12**	2.6	4.2 ± 0.05	4.3 ± 0.10	1.0	1.8	1.9	30
MXF	−0.28	5.0 ± 0.20	10.4 ± 0.20**	2.1	8.3 ± 0.12	7.8 ± 0.09	0.9	3.3	2.6	25
GRX	0.03	3.1 ± 0.12	11.8 ± 0.78**	3.8	7.3 ± 0.26	7.2 ± 0.28	1.0	4.2	4.6	40
PFX	0.25	7.1 ± 0.28	9.8 ± 0.19**	1.4	8.7 ± 0.36	8.7 ± 0.20	1.0	1.6	1.1	11

^a*, P < 0.01, **, P < 0.001.

^bCalculated as the absolute difference between P_app in the presence and absence of PSC-833. Data are expressed as the means ± SEM of results of three experiments.