TABLE 2.

Population PK parameter estimates for unbound polymyxin B after pulmonary and intravenous administration in neutropenic infected mice

Parameter	Description	Unit	Estimated value	SEa (%)
VE1	ELF1 vol of distribution	Liters/kg	3.32 × 10−4	11.7
VE2	ELF2 vol of distribution	Liters/kg	1.49 × 10−2	14.5
VC	Vol of distribution of central plasma compartment	Liters/kg	3.06	2.05
VP	Vol of distribution of peripheral plasma compartment	Liters/kg	1.56	1.15
CLD, ELF	ELF intercompartmental clearance	Liters/h/kg	3.97 ×10−3	2.07
CLD, Plasma	Plasma intercompartmental clearance	Liters/h/kg	3.51	6.62
CLTotal	Total clearance	Liters/h/kg	3.54	0.48
CLELF, Plasma	Intercompartmental clearance ELF to plasma	Liters/h/kg	4.08 × 10−3	6.18
CLPlasma, ELF	Intercompartmental clearance plasma to ELF	Liters/h/kg	1.14 × 10−4	4.69
fu	Unbound fraction	%	4.60 × 10−2 (fixed)	NA
F	Bioavailability	%	99.3	6.89
t1/2	Elimination half-lifeb	h	0.60	ND

^aNA, not applicable; ND, not determined.

^bCalculated using t_1/2 = ln(2) · V_C/CL_Total.