Improvement of solubility and targetability of radioiodinated hypericin by using sodium cholate based solvent in rat models of necrosis

AbstractHypericin (Hyp) is newly recognized as a necrosis avid agent, but its poor solubility imposes a great hindrance in clinical application. The aim of this paper was to explore sodium cholate (NaCh) as a potential solvent for Hyp and assess the targetability of 131I-Hyp in rat necrosis models. Hyp solubility in NaCh solutions was evaluated by equilibrium solubility measurement. Biodistribution of 131I-Hyp in NaCh solutions and mixed organic solvents was investigated in rat models of liver and muscle necrosis examined with MRI and SPECT/CT in vivo. In addition, pharmacokinetics of 131I-Hyp in NaCh solutions was studied in healthy rats. Results showed NaCh could improve Hyp solubility and 131I-Hyp incubated in NaCh solutions/rat plasma was stable up to 120 h. On SPECT/CT images at 24 h post injection, liver infarction location appeared as hot spots. Liver necrosis-to-liver ratios were 12.2, 10.0, 9.6 and 8.2 in 60, 15, 2 mmol/L of NaCh solutions and organic solvents, and muscle necrosis-to-liver ratios...