Pharmacokinetics in Intact Rats of N,N,N′,N′-Ethylenediaminetetrakis-(Methylenephosphonic Acid) Labeled with Gallium-68

• Published in: Pharmaceutical chemistry journal Vol. 51; no. 5; pp. 331 - 336
• Main Authors: Petriev, V. M., Tishchenko, V. K., Smoryzanova, O. A., Skvortsov, V. G.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.08.2017; Springer
• Subjects: Cancer metastasis; Cytokinins; Medicine; Molecular-Biological Problems of Drug Design and Mechanism of Drug Action; Organic Chemistry; Pharmacology/Toxicology; Pharmacy; Phosphonates; pharmacokinetics; ′; ethylenediaminetetrakis(methylenephosphonic acid); gallium-68; ,
• ISSN: 0091-150X; 1573-9031
• DOI: 10.1007/s11094-017-1608-1

Pharmacokinetic studies of the new bone-seeking radiopharmaceutical (RP) 68 Ga-labeled N , N , N ′, N ′-ethylenediaminetetrakis(methylenephosphonic acid) (EDTMP) for PET diagnosis of bone metastases showed that 68 Ga-EDTMP accumulated rapidly in bone 1 h after i.v. injection, e.g., up to 3.55 ± 0.20%/g in femur, 2.24 ± 0.13%/g in vertebrae, 2.00 ± 0.21%/g in rib, and 1.81 ± 0.10%/g in skull, was cleared rapidly from blood, and had minimal uptake in internal organs and tissues. Most of the activity was excreted through the urinary tract. Knee joints also had significant 68 Ga-EDTMP accumulations. It was found that the bone concentration of 68 Ga-EDTMP was significantly greater than that of 68 GaCl 3 ( p < 0.001 – 0.05). The ratios of specific activity in bone to those in organs and tissues (differential accumulation factors, DAFs) were greater than unity at all time points. For example, the maximum femur/blood and femur/muscle ratios were 8.00 ± 1.31 and 43.1 ± 7.4. Thus, 68 Ga-EDTMP could be considered a potential RP for PET imaging of bone damage.