Table 1.

[¹¹C]CS1P1 specifications and validation data

Quality control test	Release criteria	Validation 1	Validation 2	Validation 3	Validation 4d
Product activity
(GBq, decay corrected to EOB)	> 5.0	16.2	12.5	12.9	14.6
Appearancea	Clear, particle-free and colorless	Pass	Pass	Pass	Pass
pH	4.5 – 7.5	5.0	5.0	5.0	5.0
Filter integrity	Meet manufacturer’s requirement	Pass	Pass	Pass	Pass
Radionuclidic identity	19.32 – 21.35 min	20.35 min	20.36 min	20.36 min	20.35 min
Radiochemical identityb	Retention time of [11C]CS1P1 and injected CS1P1 must be within ± 10%	Pass	Pass	Pass	Pass
Radiochemical purityb	≥ 90%	96.6%	100%	100%	98.2%
Radiochemical stability	Purity > 90% at 1.0 h	Pass	Pass	Pass	Pass
Molar activity (GBq/μmol, decay corrected to EOB)	> 500	2289	1818	5281	1172
Chemical purity: Mass of CS1P1	≤ 10.0 μg/injected dose	3.63 μg/total volume	3.53 μg/total volume	1.25 μg/total volume	6.40 μg/total volume
Total unidentified mass impurities	All to be ≤ 1.0 μg/injected dose	0.50 μg/total volume	0.41 μg/total volume	0.65 μg/total volume	0.21 μg/total volume
Residual solvent: acetonitrilec	≤ 0.41 μg/mL (4.1 μg/day max)	< 0.050 μg/mL	< 0.050 μg/mL	< 0.050 μg/mL	< 0.050 μg/mL
Residual solvent: ethanolc	≤ 100 μg/mL	85.8 μg/mL	72.4 μg/mL	67.5 μg/mL	72.1 μg/mL
Bacterial endotoxin	≤ 175 EU/total dose	< 46.5 EU	< 53.5 EU	< 52.0 EU	< 48.0 EU
Sterility test	No visible microorganism growth	Pass	Pass	Pass	Pass

^aVisual inspection for color and particulates;

^bdetermined by HPLC;

^cdetermined by GC;

^d[¹¹C]CS1P1 was synthesized using the [¹¹C]CO₂ generated from the RDS-111 cyclotron with bombardment of 45 min at beam of 60 μA.