Intravenous Administration (iv)
Compound Cpa (mg/mL) tmax (h) AUClast (h·mg/mL) AUCinf (h·mg/mL) MRTlast (h) Cl (mL/h/kg) V (L/kg) t½ (h)  
Free acid 134 ± 29 0.14 ± 0.10 102 ± 34 102 ± 34 0.89 ± 0.13 435 ± 165 0.48 ± 0.21 0.76 ± 0.06  
Citric acid salt 177 ± 40 0.08 ± 0.00 122 ± 24 122 ± 24 0.76 ± 0.06 340 ± 65 0.34 ± 0.08 0.69 ± 0.06  
Gentisic acid salt 116 ± 9 0.08 ± 0.00 99 ± 23 99 ± 23 0.81 ± 0.11 424 ± 104 0.40 ± 0.08 0.65 ± 0.06  
Meglumine saltb 192 0.08 149 149 0.60 273 0.27 0.69  
Tromethamine salt 184 ± 54 0.08 ± 0.00 131 ± 23 131 ± 23 0.74 ± 0.07 317 ± 52 0.34 ± 0.07 0.75 ± 0.05  
Oral Administration (po)
Compound Cmax (mg/mL) tmax (h) AUClast (h·mg/mL) AUCinf (h·mg/mL) MRTlast (h) Clc(mL/h/kg) Vc (L/kg) t½ (h) Fd (%)
Free acid 1.7 ± 2.0 0.50 ± 0.00 3.8 ± 4.6 4.0 ± 4.6 1.66 ± 0.08 405 ± 6 0.71 ± 0.06 1.22 ± 0.10 3.9 ± 4.5
Citric acid salt 2.8 ±3.3 1.17 ± 0.76 3.9 ± 4.1 4.1 ± 4.1 1.46 ± 0.29 334 ± 7 0.47 ± 0.20 0.97 ± 0.41 3.3 ± 3.4
Gentisic acid salt 0.8 ± 0.2 0.83 ± 0.29 1.5 ± 0.3 1.6 ± 0.3 1.53 ± 0.46 411 ± 3 0.67 ± 0.33 1.13 ± 0.55 1.6 ± 0.3
Meglumine salt 3.7 ± 5.3 0.83 ± 0.29 6.3 ± 9.0 6.5 ± 9.1 1.40 ± 0.66 267 ± 9 0.50 ± 0.22 1.27 ± 0.54 4.3 ± 6.1
Tromethamine salt 2.7 ± 3.5 0.50 ± 0.00 3.6 ± 4.0 3.7 ± 4.0 1.24 ± 0.35 318 ± 6 0.57 ± 0.36 1.23 ± 0.77 2.8 ± 3.0

a Cp is the first measurable concentration in plasma after dose administration.
b One rat died immediately after iv dose administration, and results are derived from samples collected in two animals; no standard deviation is available.
c For po administrations, V and Cl were calculated from V/F·F and Cl/F·F, respectively.
d The bioavailability F is expressed as a percentage.

Table 2: Mean pharmacokinetic parameters of 5-LIO(Me-3,2-HOPO) and four salt forms after a single 100 mmol/kg iv and po administration in male Sprague-Dawley rats (n = 3).