Table 2. Drug concentration in plasma and brain 2 and 24 h after SC administration of an equivalent molar dose rate of MLs in Mdr1ab(−/−) mice.

	Drug concentration in plasma (pmol/ml)		Drug concentration in brain (pmol/g)		Brain-to-plasma concentration ratio (ml/g)
	2 h	24 h	2 h	24 h	2 h	24 h
Ivermectin	57.9±22.9	22.0±8.1	43.9±15.7	100.2±29.7	0.8±0.4	4.8±1.6
Moxidectin	60.0±14.5	42.8±9.3***	18.8±2.8*	93.0±28.9	0.3±0.1*	2.2±0.7**

Ivermectin (IVM) or moxidectin (MOX) was administered subcutaneously in Mdr1ab(−/−) mice (6 per drug) at similar molar dose rate (0.23 µmol/kg, corresponding to 0.20 mg/kg and 0.15 mg/kg for IVM and MOX, respectively). Mice were sacrificed at 2 or 24 h after treatment. Drug concentrations were determined in plasma and brain, and the brain/plasma concentration ratios were calculated.

^*p<0.05,

^**p<0.01,

^***p<0.001 vs IVM.