Technetium-99m-alendronate: a new radiopharmaceutical for bone scanning.
The purpose of this paper is to report the preparation of a new technetium-99m-radiopharmaceutical for bone scanning. The chelating agent for 99mTc is a new bisphosphonate, alendronate, 4-amino-1-hydroxy-butylidene-1, 1-bisphosphonate (ABP) used as a treatment for osteoporosis. ABP, because of its amino group, seems to be better suited to form a strong and stable complex with technetium-99m and therefore might be better than 99mTc-etidronate (HEDP) or 99mTc-medronate (MDP) for bone scanning. A sterile dry kit containing APB, a reducing agent and a stabilizer was prepared. The parameters studied were molar concentrations, pH, shelf life, labeling efficiency and radiochemical purity. The oven dried sterile kit was formulated with 5 mg ABP, 0.25 mg stannous fluoride and 0.025 mg gentisic acid at pH 2.5-3.5. The labeling efficiency with 20-1500 MBq of pertechnetate (99mTcO4-) was over 95% at room temperature and was stable for 5 h. Technetium-99m-alendronate was tested in two rabbits and it proved to be a promising new radiopharmaceutical for bone scanning. Work is underway to study 99mTc-ABP biodistribution in a statistically significant number of laboratory animals and, later on, to determine radiopharmacokinetic parameters in normal volunteers.
Arteaga de Murphy
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C
Departamento de Medicina Nuclear y Clinica de Tiroides, Instituto Nacional de la Nutrición Salvador Zubirán, México, D.F.
Meléndez-Alafort
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L
Montoya-Molina
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Sepúlveda-Méndez
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J
D019386:Alendronate / Q000494:pharmacology; D000818:Animals; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D006863:Hydrogen-Ion Concentration; D007553:Isotope Labeling / Q000379:methods; D015609:Organotechnetium Compounds / Q000494:pharmacology; D011817:Rabbits; D011868:Radioisotopes; D011877:Radionuclide Imaging; D011933:Reagent Kits, Diagnostic
D015609:Organotechnetium Compounds; D011868:Radioisotopes; D011933:Reagent Kits, Diagnostic; D019386:Alendronate