Table 1 In vitro characterisation results of [⁶⁸Ga]Ga-FR and [⁶⁸Ga]Ga-FRH complexes. Log P, protein binding (expressed as a percentage of plasma protein-bound activity of the total activity used) and stability in human serum, 6 mM DTPA, PBS, 0.1 M FeCl₃ and 0.1 mM FeCl₃

Log P (n = 3)

− 2.72 ± 0.12

− 1.91 ± 0.11

Incubation time (min)

30

60

120

30

60

120

Protein binding (%) (n = 2)

5.78 ± 2.26

6.55 ± 1.97

6.7 ± 2.52

50.77 ± 1.53

47.24 ± 3.83

51.11 ± 2.90

Stability in human serum (%) (n = 3)

94.26 ± 4.86

94.48 ± 4.61

90.35 ± 8.46

98.55 ± 2.47

99.08 ± 1.54

98.88 ± 1.89

Stability in 0.1 M FeCl₃ (%) (n = 3)

5.67 ± 2.91

4.13 ± 2.49

4.90 ± 1.81

3.93 ± 3.85

0.40 ± 0.52

0.80 ± 0.46

Stability in 0.1 mM FeCl₃ (%) (n = 3)

95.97 ± 0.85

96.63 ± 0.25

94.70 ± 0.62

98.75 ± 1.18

98.77 ± 1.20

99.47 ± 1.89

Stability in 6 mM DTPA (%) (n = 3)

94.57 ± 3.04

94.37 ± 1.88

93.77 ± 1.62

98.00 ± 1.05

98.63 ± 1.80

97.98 ± 2.53

Stability in PBS (%)(n = 3)

94.30 ± 2.91

95.93 ± 1.50

95.40 ± 0.68

98.34 ± 1.76

99.33 ± 0.56

99.41 ± 1.02