Technetium (99mTc) medronic acid

Technetium (^99mTc) medronic acid is a pharmaceutical product used in nuclear medicine to localize bone metastases^[1] as well as other diseases that can alter the natural turn-over in the bone by bone scintigraphy.^[2]

Technetium (^99mTc) medronic acid

Clinical data
Trade names	Mdp-Bracco
License data	US DailyMed: Medronate
Routes of administration	Intravenous
ATC code	V09BA02 (WHO)
Legal status
Legal status	US: ℞-only
Identifiers
IUPAC name Methylenebis(phosphonic acid) technetium (99mTc)
CAS Number	121524-79-6
PubChem CID	157443
DrugBank	DB09138 Y
ChemSpider	34995234
UNII	X89XV46R07
KEGG	D02029
ChEBI	CHEBI:32186
ChEMBL	ChEMBL2110576
CompTox Dashboard (EPA)	DTXSID80230782
Chemical and physical data
Formula	CH6O6P2 • x99mTc
Molar mass	unknown
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Chemistry

The drug is a complex of medronic acid (MDP, methylene diphosphonate), the simplest bisphosphonate, with technetium-99m (^99mTc), a radionuclide that emits gamma rays. The exact structure of the complex is not known.^[2][3]

Manufacture

^99mTc-MDP must be prepared in a radiopharmacy. It is usually supplied as a "cold kit" to which radioactive ^99mTc from a generator is added. Kit composition may vary between suppliers, but contents typically includes medronic acid, stannous chloride dihydrate and sometimes ascorbic acid.^[4] Pertechnetate, eluted from the generator is added to the kit vial, which is swirled and left to stand. The labelling efficiency, an indication of how much ^99mTc remains in pertechnetate form rather than bound to the MDP, can be measured using chromatography.^[5][6][7][8]